https://www2.icp.uni-stuttgart.de/~icp/mediawiki/api.php?action=feedcontributions&user=Intern&feedformat=atom
ICPWiki - User contributions [en]
2022-08-14T06:23:20Z
User contributions
MediaWiki 1.35.7
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=File:Sim_Meth_II_SS_10_11_msd.pl.txt&diff=9520
File:Sim Meth II SS 10 11 msd.pl.txt
2011-06-24T11:56:10Z
<p>Intern: </p>
<hr />
<div></div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=File:Sim_Meth_II_SS_10_11_tutorial5-2.tcl.txt&diff=9519
File:Sim Meth II SS 10 11 tutorial5-2.tcl.txt
2011-06-24T11:56:05Z
<p>Intern: </p>
<hr />
<div></div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=File:Sim_Meth_II_SS_10_11_tutorial5-1.tcl.txt&diff=9518
File:Sim Meth II SS 10 11 tutorial5-1.tcl.txt
2011-06-24T11:55:59Z
<p>Intern: </p>
<hr />
<div></div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=File:Sim_Meth_II_T5_SS_10_11.pdf&diff=9517
File:Sim Meth II T5 SS 10 11.pdf
2011-06-24T11:55:51Z
<p>Intern: </p>
<hr />
<div></div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Simulationsmethoden_in_der_Physik_2_/_Simulation_methods_in_physics_2_(SS_2011)&diff=9516
Simulationsmethoden in der Physik 2 / Simulation methods in physics 2 (SS 2011)
2011-06-24T11:55:08Z
<p>Intern: /* Tutorials */</p>
<hr />
<div>== Overview ==<br />
<br />
;Type<br />
:Lecture (2 SWS) and Tutorials (1 SWS)<br />
: <br />
;Lecturer<br />
:Prof. Dr. [[Christian Holm]], JP Dr. [[Axel Arnold]], Dr. [[Marcello Sega]] (Lecture); [[Olaf Lenz]] and [[Peter Košovan]] (Tutorials)<br />
;Course language<br />
:Deutsch oder Englisch, wie gewünscht - German or English, by vote<br />
<br />
;Lectures<br />
:Time: Thursdays, 11:30 - 13:00, Room V 57.06 <br />
;Tutorials<br />
:Time: Friday, 14:00-15.30, 2 hours/(every other week), Room U 104<br />
<br />
The lecture is accompanied by hands-on-tutorials which will take place in the CIP-Pool of the ICP, Pfaffenwaldring 27, U 108. They consist of practical exercises at the computer, like small programming tasks, simulations, visualization and data analysis.<br />
The tutorials build on each other, therefore continuous attendance is expected.<br />
<br />
Note: students from the COMMAS master will have to attend tutorials every week, and one extra tutorial is expected. Course can count then as 2SWS plus 2SWS tutorials<br />
<br />
=== Scope ===<br />
<br />
The course intends to give an overview about modern simulation methods<br />
used in physics today. The stress of the lecture will be to introduce different<br />
approaches to simulate a problem, hence we will not go too to deep into specific details but rather try to cover a broad range of methods. For an idea about the content look at the lecture schedule.<br />
<br />
=== Prerequisites ===<br />
We expect the participants to have basic knowledge in classical and statistical mechanics, thermodynamics, electrodynamics, and partial differential equations, as well as knowledge of a programming language (preferably C or C++). The knowledge of the previous course Simulation Methods I is expected.<br />
<br />
=== Certificate Requirements ===<br />
:1. Attendance of the exercise classes<br />
:2. Obtaining 50% of the possible marks in the hand-in exercises<br />
<br />
There will be a final grade for the Module "Simulation Methods" (this module consists of both lectures, Sim I plus Sim II) determined at the end of lecture Simulation Methods II.<br />
<br />
The final grade will be determined in the following way: There will be an oral examination performed at (or after) the end of the course Simulation Methods II (SS 2011).<br />
<br />
NOTE: students from the COMMAS master will have to present, at the end of the course, a supplementary project (topic to be discussed with tutors). <br />
<br />
=== Recommended literature ===<br />
<bibentry>frenkel02b,allen87a,rapaport04a,landau05a ,newman99a</bibentry><br />
<br />
=== Useful online resources ===<br />
<br />
* E-book: D.P. Landau and K. Binder: [http://www.netlibrary.com/urlapi.asp?action=summary&v=1&bookid=139749 A guide to Monte Carlo Simulations in Statistical Physics]<br />
<br />
* Linux cheat sheet {{Download|Sim_Meth_I_T0_cheat_sheet_10_11.pdf|here}}.<br />
<br />
* A good and freely available book about using Linux: [http://writers.fultus.com/garrels/ebooks/Machtelt_Garrels_Introduction_to_Linux_3nd_Ed.pdf Introduction to Linux by M. Garrels]<br />
<br />
* [http://t16web.lanl.gov/Kawano/gnuplot/index-e.html Not so frequently asked questions about GNUPLOT] (Often used by myself as a cheat sheet)<br />
<br />
* [http://homepage.tudelft.nl/v9k6y/imsst/index.html Introduction to Molecular Simulation and Statistical Thermodynamics]<br />
<br />
* Be careful when using Wikipedia as a resource. They may contain a lot of useful information, but also a lot of nonsense, because anyone can write into them.<br />
<br />
== Lecture ==<br />
{| class="prettytable"<br />
|-valign="top"<br />
!Date !! Subject<br />
|-<br />
| 28.04.2011 || Ab initio methods, Quantum mechanics <br />
|-<br />
| 05.05.2011 || Hartree-Fock, Density functional theory, Carr-Parinello MD<br />
|-<br />
| 12.05.2011 || Classical force fields, Atomistic simulations, Biomolecules<br />
|-<br />
| 19.05.2011 || Water models, Born model of solvation<br />
|-<br />
| 26.05.2011 || Coarse-grained models, simulations of macromolecules and soft matter<br />
|-<br />
| 02.06.2011 || Holiday (Christi Himmelfahrt)<br />
|-<br />
| 09.06.2011 || Long range interactions in periodic boundary conditions<br />
|-<br />
| 16.06.2011 || '' Holiday (Pfingsten) ''<br />
|-<br />
| 23.06.2011 || '' Holiday (Fronleichnam) ''<br />
|-<br />
| 30.06.2011 || Hydrodynamic methods: Lattice-Boltzmann, Brownian Dynamics, DPD, SRD<br />
|-<br />
| 01.07.2011 || Poisson-Boltzmann '' Extra lecture in tutorial time''<br />
|-<br />
| 07.07.2011 || Hydrodynamic methods II<br />
|-<br />
| 14.07.2011 || Advanced MC methods<br />
|-<br />
| 21.07.2011 || Advanced MC/MD methods<br />
|-<br />
| 28.07.2011 || Free energy methods<br />
|}<br />
<br />
== Tutorials ==<br />
<br />
;Obtaining extra points<br />
:The first person who identifies a bug in the code provided by the tutors gets an extra point and one additional extra point if he/she can fix the bug. The same applies to finding a mistake in the worksheets which significantly changes the meaning. We are also thankful for pointing out misprints, but these are not awarded extra points.<br />
<br />
;Scheduling of tutorials<br />
:Tutorials are scheduled every two weeks (see table below). In the week between the tutorials, the tutors will be available to help the you with any problems. Since participation is optional, it is recommended that you notify the tutors that you are intending to come and seek their assistance.<br />
<br />
=== Tutorial 1 - Error analysis ===<br />
* '''Tutorial on 6.5.2011''' ([[Peter Košovan]])<br />
* {{Download|Sim_Meth_II_T1_SS_10_11.pdf|Worksheet for tutorial 1}}<br />
* {{Download|Sim_Meth_II_T1_SS_10_11.tar.gz|Code for tutorial 1|tar}}.<br />
<br />
=== Tutorial 2 - GROMACS ===<br />
* '''Tutorial on 13.5.2011''' ([[Peter Košovan]])<br />
* '''Optional tutorial on 20.5.2011''' ([[Peter Košovan]])<br />
* {{Download|Sim_Meth_II_T2_SS_10_11.pdf|Worksheet for tutorial 2}}<br />
* {{Download|Sim_Meth_II_T2_SS_10_11.tar.gz|Code for tutorial 2|tar}}<br />
<br />
=== Tutorial 3 - {{es}}: Simulation of a coarse-grained polymer ===<br />
* '''Tutorial on 27.5.2011''' ([[Olaf Lenz]])<br />
* No optional tutorial on 3.6.2011 (almost holiday)<br />
* {{Download|Sim_Meth_II_T3_SS_10_11.pdf|Worksheet for tutorial 3}}<br />
* {{Download|Sim_Meth_II_T3_SS_10_11.tar.gz|Material for tutorial 3|tar}}<br />
* {{Download|Sim_Meth_II_SS_10_11_tutorial3.tcl.txt|tutorial3.tcl|text_x_tcl}}<br />
* {{Download|Sim_Meth_II_SS_10_11_KremerGrest86.pdf|Article of Kremer and Grest, 1986}}<br />
<br />
=== Tutorial 4 - {{es}}: Simulation of a charged rod with counterions ===<br />
* '''Tutorial on 10.6.2011''' ([[Olaf Lenz]])<br />
* No optional tutorial on 17.6.2011 (holiday)<br />
* '''Hand in report until 22.6.2011'''<br />
* {{Download|Sim_Meth_II_T4_SS_10_11.pdf|Worksheet for tutorial 4}}<br />
* {{Download|Sim_Meth_II_SS_10_11_tutorial4.tcl.txt|tutorial4.tcl|text_x_tcl}}<br />
* {{Download|Deserno00a.pdf|Article of Deserno, 2000}}<br />
<br />
=== Tutorial 5 - {{es}}: Lattice-Boltzmann fluid ===<br />
* '''Tutorial on 24.6.2011''' ([[Olaf Lenz]])<br />
* no tutorial on 1.7.2011: replacement lecture ''Poisson-Boltzmann''<br />
* '''Optional tutorial on 8.7.2011''' ([[Olaf Lenz]])<br />
* {{Download|Sim_Meth_II_T5_SS_10_11.pdf|Worksheet for tutorial 5}}<br />
* {{Download|Sim_Meth_II_SS_10_11_tutorial5-1.tcl.txt|tutorial5-1.tcl|text_x_tcl}}<br />
* {{Download|Sim_Meth_II_SS_10_11_tutorial5-2.tcl.txt|tutorial5-2.tcl|text_x_tcl}}<br />
* {{Download|Sim_Meth_II_SS_10_11_msd.pl.txt|msd.pl|application_x_perl}}<br />
<br />
=== Tutorial 6 - Advanced MC/MD ===<br />
* '''Tutorial on 15.7.2011''' ([[Peter Košovan]])<br />
* '''Optional tutorial on 22.7.2011''' ([[Peter Košovan]])<br />
<br />
=== Tutorial 7 - Closing ceremony ===<br />
* Might involve experiments of the effect of dilute alcoholic watery solutions on the human body<br />
* '''Tutorial on 29.7.2011''' ([[Peter Košovan]], [[Olaf Lenz]])<br />
<br />
=== Guidelines for submitting tutorial reports ===<br />
<br />
Homework for the tutorials should be submitted in the form of a report. It has to be submitted via e-mail as a '''single pdf document''' or alternatively as a paper printout. Handwritten reports will also be accepted. Source code should always be sent via e-mail. If the code concerns only a few lines, it may be included in the text of the report. Reports clearly not meeting these requirements may be rejected without evaluation.<br />
<br />
Identical pieces of reports annihilate when submitted by different people producing anti-points for both. The amount of anti-points grows exponentially with the similarity. It is fine if you help each other and discuss your results, but each part of the report has to be an original, not a copy from your neighbour.<br />
<br />
If you have a technical problem on the CIP pool computers, e.g. a missing program or library or something else which does not allow you to perform a certain task, ask the tutor for assistance. Saying in your report "I was not able to run program XXX, therefore I do not provide answer to Task YY." cannot be awarded any points.<br />
<br />
;Deadline<br />
:Approximately 10 days after the tutorial, but no later than Wednesday 8:00 of the week when the next worksheet is going to be handed out. Reports on paper can be handed in personally until lunch break on the same day.<br />
:In case of special circumstances (illness, accident, ...) contact the tutor immediately via e-mail to agree on an alternative deadline.<br />
<br />
;Text of the report<br />
:Has to contain author name, student ID and date.<br />
:Should be subdivided into sections, each section being clearly related to one task of the homework.<br />
:Must be written in sentences, not points like in a presentation. <br />
:All conclusions must be explained and when appropriate, supported by data (plots, tables). In case a derivation is required, all intermediate steps have to be clearly understandable or explained in the text.<br />
:For each simulation, it has to be clear, what were the input parameters, so that it can be re-run.<br />
<br />
;Figures and plots<br />
:Each figure has to have a number and a caption or title saying what is in the figure.<br />
:In text, refer to figures by the number or title, so that it is clear which figure you are referring to.<br />
:Each plot has to have labels on axes with font size comparable to other text. Plots without labels will not be considered.<br />
:Data points should fill a major part of plot area. The point size, x- and y-scales have to be chosen appropriately so that all important features can be seen.<br />
:All figures have to be included in the report. Figures sent as separate files will not be considered.<br />
:You may optionally provide the data files. If there is a problem in your work, it may help the tutor understand where you made a mistake.<br />
<br />
;Source files<br />
:Remember that someone has to read your code, understand it and check that it is correct.<br />
:Provide all files in which you made changes!<br />
:Use variables with intuitively understandable names. If not, at least put a comment saying what it means.<br />
:If the code is more complex, add comments to it. Especially to parts which may not be straightforward to understand.<br />
:We recommend that you indent your code for better readability.</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Oberseminar:_Physik_mit_H%C3%B6chstleistungsrechnern_(SS_2011)&diff=9379
Oberseminar: Physik mit Höchstleistungsrechnern (SS 2011)
2011-05-18T13:47:56Z
<p>Intern: </p>
<hr />
<div>= Oberseminar: Physik mit Höchstleistungsrechnern =<br />
<br />
The ICP Oberseminar usually takes place on '''Mondays 11:30-13:00 h,''' in the seminar room ('''ICP V 27.01'''). In each seminar one speaker is expected to talk for 30-45 min. We expect all group members to be present and to participate in a lively discussion.<br />
<br />
=== For talks which do not have a fixed date yet, see [[Oberseminar_SS_2011_tentative|Tentative Schedule]] ===<br />
<br />
== Current Schedule (confirmed) ==<br />
<br />
'''April 2011'''<br />
<br />
{|class="prettytable"<br />
|'''Shifted time:''' <br> Monday, 18.4.2011 <br> 12:30-14 h<br />
| Robert Ramsperger <br> 2. Physikalisches Institut, Universität Stuttgart<br />
| Driven Lattice Gases in Contact<br />
|-<br />
|'''Shifted day & time:'''<br> Tuesday, 26.4.2011 <br> 16-17:30 h Lesesaal<br />
|<br />
Markus Gusenbauer <br><br />
Ivan Cimrák <br> <br><br />
Sankt Pölten University of Applied Sciences, Austria<br />
| Self-organizing magnetic beads in lattice-Boltzmann blood flow with immersed elastic and rigid particles<br />
|-<br />
|}<br />
<br />
'''May 2011'''<br />
<br />
{|class="prettytable"<br />
| Monday, 2.5.2011, <br> 11:30-13:00 h<br />
| [[Peter Košovan | Peter Košovan]] <br> ICP<br />
| Diffusion of tracer particles in hydrogels<br />
|-<br />
| Monday, 9.5.2011 <br> 11:30-13:00 h<br />
| Pedro Sanchez, ICP<br />
| Semiflexible magnetic filaments near attractive flat surfaces<br />
|-<br />
| Monday, 16.5.2011, <br> 11:30-13:00 h<br />
| [[Marcello Sega | Marcello Sega]] <br> ICP<br />
| Dielectric response - the true story<br />
|-<br />
<br />
| Tuesday, 24.5.2011, <br> '''time will be anounced'''<br />
<!--- (15:00-16:30 h) ---><br />
| [[Dominic Röhm|Dominic Röhm]], ICP<br />
| Lattice Boltzmann Simulations on GPUs<br />
|-<br />
| Monday, 30.5.2011, <br> 11:30-13:00 h<br />
| [[Florian Weik|Florian Weik]], ICP <br><br />
[[Florian Zeller|Florian Zeller]], ICP<br />
| Errors in P3M <br> <br />
Using Electrophoresis to Simulate Nanosized Pumping Mechanisms<br />
|-<br />
|}<br />
<br />
'''June 2011'''<br />
<br />
{|class="prettytable"<br />
| Monday, 6.6.2011, <br> 11:30-13:00 h<br />
| [[Nadezhda Gribova|Nadezhda Gribova]] <br> ICP<br />
| TBA<br />
|-<br />
| Monday, 13.6.2011, <br> 11:30-13:00 h<br />
| ''' No seminar '''<br />
| ''' Holiday '''<br />
|-<br />
| Monday, 20.6.2011, <br> 11:30-13:00 h<br />
| N/A<br />
| TBA<br />
|-<br />
| Monday, 27.6.2011, <br> 11:30-13:00 h<br />
| N/A<br />
| TBA<br />
|-<br />
|}<br />
<br />
<br />
''' July 2011'''<br />
<br />
{|class="prettytable"<br />
| Monday, 4.7.2011, <br> 11:30-13:00 h<br />
| N/A<br />
| TBA<br />
|-<br />
| Monday, 11.7.2011, <br> 11:30-13:00 h<br />
| N/A<br />
| TBA<br />
|-<br />
| Monday, 18.7.2011, <br> 11:30-13:00 h<br />
| N/A<br />
| TBA<br />
|-<br />
| Monday, 25.7.2011, <br> 11:30-13:00 h<br />
| N/A<br />
| TBA<br />
|-<br />
|}</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Oberseminar_SS_2011_tentative&diff=9378
Oberseminar SS 2011 tentative
2011-05-18T13:47:43Z
<p>Intern: /* Tentative Schedule */</p>
<hr />
<div>=== For confirmed talks see [[Oberseminar_SS_2011|Oberseminar SS 2011 Schedule (confirmed)]] ===<br />
<br />
== Tentative Schedule ==<br />
<br />
Pleas notice that this is '''not''' the official schedule for the Oberseminar.<br />
<br />
{|class="prettytable"<br />
<br />
| 20. June 2011<br />
| [[Stefan Kesselheim|Stefan Kesselheim]], ICP<br />
| TBA<br />
|-<br />
<br />
| 4.7. 2011<br />
| [[Wojciech Müller|Wojciech Müller]], ICP <br><br />
Konrad Breitsprecher, ICP<br />
| TBA <br><br />
Capacitance of ionic liquids<br />
|-<br />
<br />
| July 2011<br />
| [[Rudolf Weeber|Rudolf Weeber]], ICP<br />
| Magnetic gels<br />
|-<br />
<br />
| July 2011<br />
| [[Oliver Hönig|Oliver Hönig]], ICP<br />
| Travelling Waves in Porous Media<br />
|-<br />
<br />
| July 2011<br />
| Karsten Keller, ISD<br />
| Multifield modeling of hydrogels<br />
|-<br />
<br />
<br />
| 2011<br />
| [[Olaf Lenz|Olaf Lenz]], ICP<br />
| Problems of parallel off-lattice Monte-Carlo<br />
|-<br />
|}</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=ICP-Kolloquium_SS_2011&diff=9196
ICP-Kolloquium SS 2011
2011-04-07T13:43:32Z
<p>Intern: /* July */</p>
<hr />
<div>= Colloquium: Physics on High Performance Computers =<br />
<br />
The ICP Colloquium usually takes place on '''Mondays 14-16 h,''' in the seminar room '''ICP V 27.01'''. Distinguished external speakers present their recent results in the fields of computational theoretical soft and granular matter. Talks are typically around one hour, and there should be enough time for discussions.<br />
<br />
== Current Schedule ==<br />
<br />
=== May ===<br />
{|class="prettytable"<br />
<br />
|<br />
Monday<br><br />
'''2. 5. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
Jürgen Vollmer,<br><br />
MPI for Dynamics and Self Organization,<br><br />
Göttingen<br />
|<br />
Rain in a Test Tube?<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''9. 5. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
Swetlana Jungblut, Universität Wien<br />
|<br />
[[Colloq SS2011, Jungblut, Crystallization of a binary Lennard-Jones mixture | Crystallization of a binary Lennard-Jones mixture]]<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''16. 5. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
NN<br />
|<br />
tba<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''23. 5. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
Michael Bader, IPVS, Universität Stuttgart<br />
|<br />
tba<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''30. 5. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
NN<br />
|<br />
cancelled<br />
|-<br />
<br />
|}<br />
<br />
=== June ===<br />
<br />
{|class="prettytable"<br />
<br />
|<br />
Monday<br><br />
'''6. 6. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
NN<br />
|<br />
tba<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''20. 6. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
NN<br />
|<br />
tba<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''27. 6. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
Frank Schreiber, Universität Tübingen<br />
|<br />
tba<br />
|-<br />
<br />
|}<br />
<br />
=== July ===<br />
{|class="prettytable"<br />
<br />
|<br />
Monday<br><br />
'''4. 7. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
Thomas Gruhn, Universität Mainz<br />
|<br />
Monte-Carlo simulations of self-assembling<br />
filament networks<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''11. 7. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
NN<br />
|<br />
tba<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''18. 7. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
Kurt Binder, Universität Mainz<br />
|<br />
Monte Carlo methods for estimating interfacial free energies and line tensions<br />
|-<br />
<br />
|<br />
Monday<br><br />
'''25. 7. 2011'''<br><br />
'''14:00-15:30'''<br />
|<br />
NN<br />
|<br />
tba<br />
|-<br />
<br />
|}</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Theses&diff=9143
Theses
2011-03-08T17:12:18Z
<p>Intern: /* Diplom- und Masterarbeiten {{german}} */</p>
<hr />
<div>If you are looking for topics for a PhD thesis, have a look at [[Open Positions]].<br />
<br />
== Diplom- und Masterarbeiten {{german}} ==<br />
<br />
Diplom- und Masterarbeiten können bei uns im Bereich ''Simulation und Theorie weicher Materie'' durchgeführt werden.<br />
<br />
Dies umfasst insbesondere Nukleation, Ferrofluide, Hydrogele sowie Polymere und Biomoleküle. Desweiteren kann sich eine Arbeit aber auch stärker an der Entwicklung von Methoden, Algorithmen und der Simulationssoftware {{es}} orientieren.<br />
<br />
Aktuelle Themen sind beispielsweise<br />
* Simulationen zur Leitfähigkeit von Polymerelektrolyten ([[Christian Holm]])<br />
* Simulationen zur Meerwasserentsalzung mittels Hydrogelen ([[Christian Holm]])<br />
* [[wd:Phasendiagramm|Phasendiagramm]] von nicht zentrierten [[wd:Dipol|Dipol]]en ([[Rudolf Weeber]])<br />
* Lösung der [[wd:Poisson-Boltzmann-Gleichung|Poisson-Boltzmann-Gleichung]] in beschränkten Geometrien ([[Alexander Schlaich]])<br />
* [[wd:Ionenkanal|Ionenkanäle]] ([[Stefan Kesselheim]])<br />
* Magnetische Gele ([[Rudolf Weeber]])<br />
* Portierung von langreichweitigen Lösern für Hydrodynamik und Elektrostatik auf [[w:GPGPU|Grakfikprozessoren]] ([[Axel Arnold]])<br />
* [[wd:Ionische Flüssigkeit|Ionische Flüssigkeiten]]: <br />
** Dielektrisches Spektrum von Modellfluiden ([[Marcello Sega]])<br />
** Coarse-grained Modelle für ionische Flüssigkeiten ([[Florian Dommert]])<br />
* Gitteralgorithmen für Probleme der Elektrohydrodynamik (GPU und CPU) <br />
* Mikrostrukturbildung und Phasenverhalten von kolloidalen Janus-Teilchen ([[Christian Holm]])<br />
* Implementierung, Verbesserung und Anwendung moderner Simulationsalgorithmen in der Software {{es}} ([[Olaf Lenz]])<br />
<br />
Wer Interesse daran hat, eine Master- oder Diplomarbeit in einem dieser Bereiche zu schreiben, der kann [[Olaf Lenz]], [[Christian Holm]] oder [[Axel Arnold]] kontaktieren, um einen Überblick über die möglichen Themen zu bekommen. Bei Interesse an einem bestimmten der oben genannten Themen kann er direkt einen der unten genannten Ansprechpartner kontaktieren.<br />
<br />
Interessierte Studierende sollten über Grundlagen der statistischen Physik/Thermodynamik, des Umgangs mit UNIX-Systemen und der Programmierung in einer Skript- oder Programmiersprache verfügen. Grundlegende Kenntnisse von Simulationstechniken oder Numerik sind von Vorteil.<br />
<br />
== Bachelorarbeiten {{german}} ==<br />
<br />
Die folgenden Themen von Bachelorarbeiten sind momentan am ICP zu vergeben. Wer gerne in unserem Bereich eine Bachelorarbeit schreiben möchte aber bei den folgenden Themen kein geeignetes Thema finden kann, der kann Kontakt mit [[Christian Holm]], [[Axel Arnold]] oder [[Olaf Lenz]] aufnehmen und nach weiteren Themen fragen.<br />
<br />
Interessierte Studierende sollten über Grundlagen der statistischen Physik/Thermodynamik, des Umgangs mit UNIX-Systemen und der Programmierung in einer Skript- oder Programmiersprache verfügen. Grundlegende Kenntnisse von Simulationstechniken oder Numerik sind von Vorteil.<br />
<br />
=== Poisson-Boltzmann-Löser in beschränkten Geometrien ===<br />
Die [[wd:Poisson-Boltzmann-Gleichung|Poisson-Boltzmann-Gleichung]] beschreibt die [[wd:Ion|Ionen]]verteilung um geladene Objekte. Sie wird standardmäßig in biomolekularen Simulationen, z.B. zur Berechnung von [[wd:freie Energie|freien Energien]] benutzt, sowie in der Simulation von geladener weicher Materie verwendet, wie beispielsweise von [[wd:Desoxyribonukleinsäure|DNS]]-Strängen oder ladungsstabilisierten [[wd:Kolloid|Kolloiden]]. In dieser Arbeit soll die PB-Gleichung mit Hilfe des PDE-Lösers des Softwarepaketes [http://www.dune-project.org/ Dune] mittels der [[wd:Finite-Elemente-Methode|Finite-Elemente-Methode]] gelöst werden. Die Ionenverteilungen verschiedener Modellgeometrien sollen untersucht und mit Hilfe expliziter [[wd:Molekulardynamik|Molekulardynamik]]-Simulationen im Softwarepaket {{ES}} überprüft werden.<br />
<br />
Ansprechpartner: [[Alexander Schlaich]]<br />
<br />
=== Parameterstudien zur Translokation von Biomolekülen durch Nanoporen ===<br />
In den letzten Jahren ist es möglich geworden, künstliche Nanoporen als Sonden in der Welt einzelner Makromoleküle zu benutzen. Bei dem Transport dieser Moleküle durch die Pore spielen elektrostatische Wechselwirkungen eine große Rolle, weil fast alle Biomoleküle (z.B. [[wd:Desoxyribonukleinsäure|DNS]] stark geladen sind. In diesem Projekt soll die Rolle der elektrostatischen Wechselwirkung für diesen Prozess mit [[wd:Molekulardynamik|molekulardynamischen Simulationen]] untersucht werden, um so die wissenschaftliche Grundlage für ein genaues Verständnis dieses Prozesses zu legen. Nur wenn das System gut verstanden ist, kann es letztlich - wie man sich erhofft - zur schnellen Sequenzierung von DNS genutzt werden. Das zugrundeliegende Softwarepaket wird {{ES}} sein.<br />
<br />
Ansprechpartner: [[Stefan Kesselheim]]<br />
<br />
=== Messung der dielektrischen Konstante in einer ionischen Flüssigkeit ===<br />
Mit einem vereinfachten Modell von harten geladenen Kugeln soll im Rahmen einer [[wd:Molekulardynamik|Molekulardynamischen Simulation]] die [[wd:Dielektrizitätskonstante|statische dielektrische Konstante]] bestimmt werden, wie sie aus Messungen mittels [[wd:Dielektrische Spektroskopie|dielektrischer Spektroskopie]] bestimmt wird.<br />
<br />
Ansprechpartner: [[Marcello Sega]] oder [[Axel Arnold]]<br />
<br />
=== Vergröberte Modelle von ionischen Flüssigkeiten ===<br />
<br />
Es existiert eine Klasse von [[wd:Ionische Flüssigkeit|ionische Flüssigkeiten]] mit Schmelzpunkten unterhalb 100&deg;, deren Eigenschaften als Lösungsmittel großes Interesse weckt. Da viele der Mechanismen, die den Charakter der ionischen Flüssigkeiten ausmachen, noch nicht vollständig erklärt sind, können vergröberte Modelle diese Moleküle helfen, entscheidende Faktoren zu identifizieren, um ein besseres Verständnis dieser Lösungsmittel zu ermöglichen. Eine klassische [[wd:Molekulardynamik|Molekulardynamikstudie]] entsprechender Kugelmodelle von Kationen und Anionen soll dazu dienen existierende Modelle zu validieren und gegebenenfalls diese zu erweitern, um einen ersten Einblick in das Prinzip der Molekulardynamik-Simulation, des Coarse-grainings und dem weiten Feld der ionischen Flüssigkeiten zu erhalten. <br />
<br />
Ansprechpartner: [[Florian Dommert]]<br />
<br />
=== Simulation ultrakalte Moleküle mit einem elektrischen Dipolmoment ===<br />
<br />
Ultrakalte Moleküle mit einem [[wd:Elektrisches Dipolmoment|elektrischen Dipolmoment]] lassen sich in einem [[wd:Optisches Gitter (Atomphysik)|optischen Gitter]] einfangen und durch ein elektrisches Feld ausrichten. Durch Manipulation des Gitters und des elektrischen Feldes lassen sich die Wechselwirkungen zwischen den Molekülen beeinflussen. In dieser Arbeit soll mit Hilfe von [[wd:Molekulardynamik|Molekulardynamik-Simulationen]] ein System untersucht werden, in dem mehrere Lagen stark dipolar wechselwirkender Moleküle übereinander angeordnet sind. Ziel der Arbeit ist es, [[wd:Grundzustand|Grundzustand]]sstrukturen zu berechnen, sowie den Einfluß der [[wd:Thermische Energie|thermischen Bewegung]] auf die Grundzustandsstrukturen zu berechnen. Das System ist hierbei gerade noch im Bereich der klassischen Physik. Als Simulationssoftware wird {{es}} zum Einsatz kommen. <br />
<br />
Ansprechpartner: [[Rudolf Weeber]]<br />
<br />
=== Gitter-Boltzmann-Simulationen auf [[wd:GPGPU|Grafikprozessoren]] ===<br />
<br />
Grafikprozessoren (GPUs) sind bei geeigneten Algorithmen mehr als 10 mal so schnell wie ein vergleichbarer konventioneller Prozessor. Zu diesen Algorithmen zählt z.B. die [[wd:Lattice-Boltzmann-Methode|Gitter-Boltzmann-Methode]] für [[wd:Strömungsdynamik|Strömungsdynamik]]. Diese Methode wird in unserer Arbeitsgruppe eingesetzt, um klassische Teilchen mit [[wd:Hydrodynamik|hydrodynamischen]] Wechselwirkungen zu simulieren. Dabei läuft eine [[wd:Molekulardynamik|Molekulardynamik-Simulation]] in der Software {{ES}}, während die Strömungsdynamik auf einer GPU gerechnet wird. Im Rahmen einer Bachelorarbeit sollen Performancemessungen an unserem Code vorgenommen werden, sowie dieser für den Einsatz in Multi-GPU-Umgebungen fit gemacht werden. Ein anderes Thema in diesem Bereich ist die Implementation neuer Randbedingungen, um etwa Mikrokanäle zu simulieren.<br />
<br />
Ansprechpartner: [[Axel Arnold]]<br />
<br />
=== Leistungsvergleich verschiedener Simulationssoftware ===<br />
<br />
Am ICP wird die Simulationssoftware {{es}} entwickelt, mit derene Hilfe [[wd:Molekulardynamik|Molekulardynamik-Simulationen]] durchgeführt werden können. Es existieren verschiedene andere Simulationssoftwarepakte (z.B. [[wd:GROMACS|GROMACS]] oder [http://lammps.sandia.gov/ Lammps]]). Im Rahmen der Bachelorarbeit sollen verschiedene Modellsysteme in den verschiedenen Simulationspaketen simuliert werden und Performancevergleiche zwischen den Paketen angestellt werden. Die Arbeit soll dabei helfen, Schwächen und Stärken der verschiedenen Pakete aufzudecken.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]<br />
<br />
=== Leistungsvergleich verschiedener Algorithmen zur Coulomb-Wechselwirkung ===<br />
<br />
Die Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] nimmt bei [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen einen beachtlichen Teil der Rechenzeit in Anspruch. Über viele Jahrzehnte wurden und werden neue Algorithmen zur Lösung dieses Problems entwickelt. Einige dieser Algorithmen sind im Programmpaket {{ES}} implementiert. Neben kurzem Einlesen in diese Methoden sollen vor allem Simulationen verschiedener Modellsysteme zum direkten Vergleich von Genauigkeit und Performance der Methoden durchgeführt werden. Die Ergebnisse sollen geeignet interpretiert und präsentiert werden.<br />
<br />
Ansprechpartner: [[Florian Rühle]]<br />
<br />
=== Verbesserung des Ewald-Algorithmus für Elektrostatische Wechselwirkungen in {{es}} ===<br />
<br />
Eine Möglichkeit zur Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] in [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen ist die [[w:Ewald summation|Ewald-Summe]]. Obwohl der Algorithmus nicht die schnellste Möglichkeit dafür ist, so eignet sich der Algorithmus wegen seiner hohen Genauigkeit sehr gut zum Vergleich mit anderen, schnellerean aber ungenaueren Methoden. Die Simulationssoftware {{es}} enthält eine Implementation der Ewald-Summe, die bislang allerdings fehlerhaft ist und nur auf einem Prozessor lauffähig ist. Ziel der Bachelorarbeit wäre es, die Implementation der Ewald-Summe in {{es}} zu korrigieren und zu parallelisieren, damit effektive Vergleiche der Methode mit anderen Verfahren angestellt werden können.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]<br />
<br />
=== Verbesserung des Tuning-Algorithmus für P3M ===<br />
<br />
Ein schneller Algorithmus zur Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] in [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen ist der P3M-Algorithmus, der in der Simulationssoftware {{es}} implementiert ist. Der Algorithmus hat zahlreiche Parameter, die seine Genauigkeit und Geschwindigkeit in unterschiedlichem Maße beeinflussen. Zur Wahl des besten Parametersatzes ("Tuning") für ein gegebenes System existiert ein einfacher heuristischer Algorithmus in {{es}}. Ziel der Bachelorarbeit wäre es, das Tuningverfahren zu verbessern. Dazu sollte sich der Studierende zunächst in den P3M-Algorithmus einarbeiten und anhand von Parameterstudien an einfachen Modellsystemen den Effekt der verschiedenen Parameter studieren, um dann den Tuning-Algorithmus gezielt zu verbessern.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Theses&diff=9142
Theses
2011-03-08T17:10:39Z
<p>Intern: /* Diplom- und Masterarbeiten {{german}} */</p>
<hr />
<div>If you are looking for topics for a PhD thesis, have a look at [[Open Positions]].<br />
<br />
== Diplom- und Masterarbeiten {{german}} ==<br />
<br />
Diplom- und Masterarbeiten können bei uns im Bereich ''Simulation und Theorie weicher Materie'' durchgeführt werden.<br />
<br />
Dies umfasst insbesondere Nukleation, Ferrofluide, Hydrogele sowie Polymere und Biomoleküle. Desweiteren kann sich eine Arbeit aber auch stärker an der Entwicklung von Methoden, Algorithmen und der Simulationssoftware {{es}} orientieren.<br />
<br />
Aktuelle Themen sind beispielsweise<br />
* Simulationen zur Leitfähigkeit von Polymerelektrolyten ([[Christian Holm]])<br />
* Simulationen zur Meerwasserentsalzung mittels Hydrogelen ([[Christian Holm]])<br />
* [[wd:Phasendiagramm|Phasendiagramm]] von nicht zentrierten [[wd:Dipol|Dipol]]en ([[Rudolf Weeber]])<br />
* Lösung der [[wd:Poisson-Boltzmann-Gleichung|Poisson-Boltzmann-Gleichung]] in beschränkten Geometrien ([[Alexander Schlaich]])<br />
* [[wd:Ionenkanal|Ionenkanäle]] ([[Stefan Kesselheim]])<br />
* Magnetische Gele ([[Rudolf Weeber]])<br />
* Portierung von langreichweitigen Lösern für Hydrodynamik und Elektrostatik auf [[w:GPGPU|Grakfikprozessoren]] ([[Axel Arnold]])<br />
* [[wd:Ionische Flüssigkeit|Ionische Flüssigkeiten]]: <br />
** Dielektrisches Spektrum von Modellfluiden ([[Marcello Sega]])<br />
** Coarse-grained Modelle für ionische Flüssigkeiten ([[Florian Dommert]])<br />
* Gitteralgorithmen für Probleme der Elektrohydrodynamik (GPU und CPU) <br />
* Janus-Teilchen<br />
* Implementierung, Verbesserung und Anwendung moderner Simulationsalgorithmen in der Software {{es}} ([[Olaf Lenz]])<br />
<br />
Wer Interesse daran hat, eine Master- oder Diplomarbeit in einem dieser Bereiche zu schreiben, der kann [[Olaf Lenz]], [[Christian Holm]] oder [[Axel Arnold]] kontaktieren, um einen Überblick über die möglichen Themen zu bekommen. Bei Interesse an einem bestimmten der oben genannten Themen kann er direkt einen der unten genannten Ansprechpartner kontaktieren.<br />
<br />
Interessierte Studierende sollten über Grundlagen der statistischen Physik/Thermodynamik, des Umgangs mit UNIX-Systemen und der Programmierung in einer Skript- oder Programmiersprache verfügen. Grundlegende Kenntnisse von Simulationstechniken oder Numerik sind von Vorteil.<br />
<br />
== Bachelorarbeiten {{german}} ==<br />
<br />
Die folgenden Themen von Bachelorarbeiten sind momentan am ICP zu vergeben. Wer gerne in unserem Bereich eine Bachelorarbeit schreiben möchte aber bei den folgenden Themen kein geeignetes Thema finden kann, der kann Kontakt mit [[Christian Holm]], [[Axel Arnold]] oder [[Olaf Lenz]] aufnehmen und nach weiteren Themen fragen.<br />
<br />
Interessierte Studierende sollten über Grundlagen der statistischen Physik/Thermodynamik, des Umgangs mit UNIX-Systemen und der Programmierung in einer Skript- oder Programmiersprache verfügen. Grundlegende Kenntnisse von Simulationstechniken oder Numerik sind von Vorteil.<br />
<br />
=== Poisson-Boltzmann-Löser in beschränkten Geometrien ===<br />
Die [[wd:Poisson-Boltzmann-Gleichung|Poisson-Boltzmann-Gleichung]] beschreibt die [[wd:Ion|Ionen]]verteilung um geladene Objekte. Sie wird standardmäßig in biomolekularen Simulationen, z.B. zur Berechnung von [[wd:freie Energie|freien Energien]] benutzt, sowie in der Simulation von geladener weicher Materie verwendet, wie beispielsweise von [[wd:Desoxyribonukleinsäure|DNS]]-Strängen oder ladungsstabilisierten [[wd:Kolloid|Kolloiden]]. In dieser Arbeit soll die PB-Gleichung mit Hilfe des PDE-Lösers des Softwarepaketes [http://www.dune-project.org/ Dune] mittels der [[wd:Finite-Elemente-Methode|Finite-Elemente-Methode]] gelöst werden. Die Ionenverteilungen verschiedener Modellgeometrien sollen untersucht und mit Hilfe expliziter [[wd:Molekulardynamik|Molekulardynamik]]-Simulationen im Softwarepaket {{ES}} überprüft werden.<br />
<br />
Ansprechpartner: [[Alexander Schlaich]]<br />
<br />
=== Parameterstudien zur Translokation von Biomolekülen durch Nanoporen ===<br />
In den letzten Jahren ist es möglich geworden, künstliche Nanoporen als Sonden in der Welt einzelner Makromoleküle zu benutzen. Bei dem Transport dieser Moleküle durch die Pore spielen elektrostatische Wechselwirkungen eine große Rolle, weil fast alle Biomoleküle (z.B. [[wd:Desoxyribonukleinsäure|DNS]] stark geladen sind. In diesem Projekt soll die Rolle der elektrostatischen Wechselwirkung für diesen Prozess mit [[wd:Molekulardynamik|molekulardynamischen Simulationen]] untersucht werden, um so die wissenschaftliche Grundlage für ein genaues Verständnis dieses Prozesses zu legen. Nur wenn das System gut verstanden ist, kann es letztlich - wie man sich erhofft - zur schnellen Sequenzierung von DNS genutzt werden. Das zugrundeliegende Softwarepaket wird {{ES}} sein.<br />
<br />
Ansprechpartner: [[Stefan Kesselheim]]<br />
<br />
=== Messung der dielektrischen Konstante in einer ionischen Flüssigkeit ===<br />
Mit einem vereinfachten Modell von harten geladenen Kugeln soll im Rahmen einer [[wd:Molekulardynamik|Molekulardynamischen Simulation]] die [[wd:Dielektrizitätskonstante|statische dielektrische Konstante]] bestimmt werden, wie sie aus Messungen mittels [[wd:Dielektrische Spektroskopie|dielektrischer Spektroskopie]] bestimmt wird.<br />
<br />
Ansprechpartner: [[Marcello Sega]] oder [[Axel Arnold]]<br />
<br />
=== Vergröberte Modelle von ionischen Flüssigkeiten ===<br />
<br />
Es existiert eine Klasse von [[wd:Ionische Flüssigkeit|ionische Flüssigkeiten]] mit Schmelzpunkten unterhalb 100&deg;, deren Eigenschaften als Lösungsmittel großes Interesse weckt. Da viele der Mechanismen, die den Charakter der ionischen Flüssigkeiten ausmachen, noch nicht vollständig erklärt sind, können vergröberte Modelle diese Moleküle helfen, entscheidende Faktoren zu identifizieren, um ein besseres Verständnis dieser Lösungsmittel zu ermöglichen. Eine klassische [[wd:Molekulardynamik|Molekulardynamikstudie]] entsprechender Kugelmodelle von Kationen und Anionen soll dazu dienen existierende Modelle zu validieren und gegebenenfalls diese zu erweitern, um einen ersten Einblick in das Prinzip der Molekulardynamik-Simulation, des Coarse-grainings und dem weiten Feld der ionischen Flüssigkeiten zu erhalten. <br />
<br />
Ansprechpartner: [[Florian Dommert]]<br />
<br />
=== Simulation ultrakalte Moleküle mit einem elektrischen Dipolmoment ===<br />
<br />
Ultrakalte Moleküle mit einem [[wd:Elektrisches Dipolmoment|elektrischen Dipolmoment]] lassen sich in einem [[wd:Optisches Gitter (Atomphysik)|optischen Gitter]] einfangen und durch ein elektrisches Feld ausrichten. Durch Manipulation des Gitters und des elektrischen Feldes lassen sich die Wechselwirkungen zwischen den Molekülen beeinflussen. In dieser Arbeit soll mit Hilfe von [[wd:Molekulardynamik|Molekulardynamik-Simulationen]] ein System untersucht werden, in dem mehrere Lagen stark dipolar wechselwirkender Moleküle übereinander angeordnet sind. Ziel der Arbeit ist es, [[wd:Grundzustand|Grundzustand]]sstrukturen zu berechnen, sowie den Einfluß der [[wd:Thermische Energie|thermischen Bewegung]] auf die Grundzustandsstrukturen zu berechnen. Das System ist hierbei gerade noch im Bereich der klassischen Physik. Als Simulationssoftware wird {{es}} zum Einsatz kommen. <br />
<br />
Ansprechpartner: [[Rudolf Weeber]]<br />
<br />
=== Gitter-Boltzmann-Simulationen auf [[wd:GPGPU|Grafikprozessoren]] ===<br />
<br />
Grafikprozessoren (GPUs) sind bei geeigneten Algorithmen mehr als 10 mal so schnell wie ein vergleichbarer konventioneller Prozessor. Zu diesen Algorithmen zählt z.B. die [[wd:Lattice-Boltzmann-Methode|Gitter-Boltzmann-Methode]] für [[wd:Strömungsdynamik|Strömungsdynamik]]. Diese Methode wird in unserer Arbeitsgruppe eingesetzt, um klassische Teilchen mit [[wd:Hydrodynamik|hydrodynamischen]] Wechselwirkungen zu simulieren. Dabei läuft eine [[wd:Molekulardynamik|Molekulardynamik-Simulation]] in der Software {{ES}}, während die Strömungsdynamik auf einer GPU gerechnet wird. Im Rahmen einer Bachelorarbeit sollen Performancemessungen an unserem Code vorgenommen werden, sowie dieser für den Einsatz in Multi-GPU-Umgebungen fit gemacht werden. Ein anderes Thema in diesem Bereich ist die Implementation neuer Randbedingungen, um etwa Mikrokanäle zu simulieren.<br />
<br />
Ansprechpartner: [[Axel Arnold]]<br />
<br />
=== Leistungsvergleich verschiedener Simulationssoftware ===<br />
<br />
Am ICP wird die Simulationssoftware {{es}} entwickelt, mit derene Hilfe [[wd:Molekulardynamik|Molekulardynamik-Simulationen]] durchgeführt werden können. Es existieren verschiedene andere Simulationssoftwarepakte (z.B. [[wd:GROMACS|GROMACS]] oder [http://lammps.sandia.gov/ Lammps]]). Im Rahmen der Bachelorarbeit sollen verschiedene Modellsysteme in den verschiedenen Simulationspaketen simuliert werden und Performancevergleiche zwischen den Paketen angestellt werden. Die Arbeit soll dabei helfen, Schwächen und Stärken der verschiedenen Pakete aufzudecken.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]<br />
<br />
=== Leistungsvergleich verschiedener Algorithmen zur Coulomb-Wechselwirkung ===<br />
<br />
Die Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] nimmt bei [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen einen beachtlichen Teil der Rechenzeit in Anspruch. Über viele Jahrzehnte wurden und werden neue Algorithmen zur Lösung dieses Problems entwickelt. Einige dieser Algorithmen sind im Programmpaket {{ES}} implementiert. Neben kurzem Einlesen in diese Methoden sollen vor allem Simulationen verschiedener Modellsysteme zum direkten Vergleich von Genauigkeit und Performance der Methoden durchgeführt werden. Die Ergebnisse sollen geeignet interpretiert und präsentiert werden.<br />
<br />
Ansprechpartner: [[Florian Rühle]]<br />
<br />
=== Verbesserung des Ewald-Algorithmus für Elektrostatische Wechselwirkungen in {{es}} ===<br />
<br />
Eine Möglichkeit zur Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] in [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen ist die [[w:Ewald summation|Ewald-Summe]]. Obwohl der Algorithmus nicht die schnellste Möglichkeit dafür ist, so eignet sich der Algorithmus wegen seiner hohen Genauigkeit sehr gut zum Vergleich mit anderen, schnellerean aber ungenaueren Methoden. Die Simulationssoftware {{es}} enthält eine Implementation der Ewald-Summe, die bislang allerdings fehlerhaft ist und nur auf einem Prozessor lauffähig ist. Ziel der Bachelorarbeit wäre es, die Implementation der Ewald-Summe in {{es}} zu korrigieren und zu parallelisieren, damit effektive Vergleiche der Methode mit anderen Verfahren angestellt werden können.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]<br />
<br />
=== Verbesserung des Tuning-Algorithmus für P3M ===<br />
<br />
Ein schneller Algorithmus zur Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] in [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen ist der P3M-Algorithmus, der in der Simulationssoftware {{es}} implementiert ist. Der Algorithmus hat zahlreiche Parameter, die seine Genauigkeit und Geschwindigkeit in unterschiedlichem Maße beeinflussen. Zur Wahl des besten Parametersatzes ("Tuning") für ein gegebenes System existiert ein einfacher heuristischer Algorithmus in {{es}}. Ziel der Bachelorarbeit wäre es, das Tuningverfahren zu verbessern. Dazu sollte sich der Studierende zunächst in den P3M-Algorithmus einarbeiten und anhand von Parameterstudien an einfachen Modellsystemen den Effekt der verschiedenen Parameter studieren, um dann den Tuning-Algorithmus gezielt zu verbessern.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Theses&diff=9141
Theses
2011-03-08T17:08:26Z
<p>Intern: /* Diplom- und Masterarbeiten {{german}} */</p>
<hr />
<div>If you are looking for topics for a PhD thesis, have a look at [[Open Positions]].<br />
<br />
== Diplom- und Masterarbeiten {{german}} ==<br />
<br />
Diplom- und Masterarbeiten können bei uns im Bereich ''Simulation und Theorie weicher Materie'' durchgeführt werden.<br />
<br />
Dies umfasst insbesondere Nukleation, Ferrofluide, Hydrogele sowie Polymere und Biomoleküle. Desweiteren kann sich eine Arbeit aber auch stärker an der Entwicklung von Methoden, Algorithmen und der Simulationssoftware {{es}} orientieren.<br />
<br />
Aktuelle Themen sind beispielsweise<br />
* Simulationen zur Leitfähigkeit von Polymerelektrolyten ([[Christian Holm]])<br />
* [[wd:Phasendiagramm|Phasendiagramm]] von nicht zentrierten [[wd:Dipol|Dipol]]en ([[Rudolf Weeber]])<br />
* Lösung der [[wd:Poisson-Boltzmann-Gleichung|Poisson-Boltzmann-Gleichung]] in beschränkten Geometrien ([[Alexander Schlaich]])<br />
* [[wd:Ionenkanal|Ionenkanäle]] ([[Stefan Kesselheim]])<br />
* Magnetische Gele ([[Rudolf Weeber]])<br />
* Portierung von langreichweitigen Lösern für Hydrodynamik und Elektrostatik auf [[w:GPGPU|Grakfikprozessoren]] ([[Axel Arnold]])<br />
* [[wd:Ionische Flüssigkeit|Ionische Flüssigkeiten]]: <br />
** Dielektrisches Spektrum von Modellfluiden ([[Marcello Sega]])<br />
** Coarse-grained Modelle für ionische Flüssigkeiten ([[Florian Dommert]])<br />
* Gitteralgorithmen für Probleme der Elektrohydrodynamik (GPU und CPU) <br />
* Janus-Teilchen<br />
* Implementierung, Verbesserung und Anwendung moderner Simulationsalgorithmen in der Software {{es}} ([[Olaf Lenz]])<br />
<br />
Wer Interesse daran hat, eine Master- oder Diplomarbeit in einem dieser Bereiche zu schreiben, der kann [[Olaf Lenz]], [[Christian Holm]] oder [[Axel Arnold]] kontaktieren, um einen Überblick über die möglichen Themen zu bekommen. Bei Interesse an einem bestimmten der oben genannten Themen kann er direkt einen der unten genannten Ansprechpartner kontaktieren.<br />
<br />
Interessierte Studierende sollten über Grundlagen der statistischen Physik/Thermodynamik, des Umgangs mit UNIX-Systemen und der Programmierung in einer Skript- oder Programmiersprache verfügen. Grundlegende Kenntnisse von Simulationstechniken oder Numerik sind von Vorteil.<br />
<br />
== Bachelorarbeiten {{german}} ==<br />
<br />
Die folgenden Themen von Bachelorarbeiten sind momentan am ICP zu vergeben. Wer gerne in unserem Bereich eine Bachelorarbeit schreiben möchte aber bei den folgenden Themen kein geeignetes Thema finden kann, der kann Kontakt mit [[Christian Holm]], [[Axel Arnold]] oder [[Olaf Lenz]] aufnehmen und nach weiteren Themen fragen.<br />
<br />
Interessierte Studierende sollten über Grundlagen der statistischen Physik/Thermodynamik, des Umgangs mit UNIX-Systemen und der Programmierung in einer Skript- oder Programmiersprache verfügen. Grundlegende Kenntnisse von Simulationstechniken oder Numerik sind von Vorteil.<br />
<br />
=== Poisson-Boltzmann-Löser in beschränkten Geometrien ===<br />
Die [[wd:Poisson-Boltzmann-Gleichung|Poisson-Boltzmann-Gleichung]] beschreibt die [[wd:Ion|Ionen]]verteilung um geladene Objekte. Sie wird standardmäßig in biomolekularen Simulationen, z.B. zur Berechnung von [[wd:freie Energie|freien Energien]] benutzt, sowie in der Simulation von geladener weicher Materie verwendet, wie beispielsweise von [[wd:Desoxyribonukleinsäure|DNS]]-Strängen oder ladungsstabilisierten [[wd:Kolloid|Kolloiden]]. In dieser Arbeit soll die PB-Gleichung mit Hilfe des PDE-Lösers des Softwarepaketes [http://www.dune-project.org/ Dune] mittels der [[wd:Finite-Elemente-Methode|Finite-Elemente-Methode]] gelöst werden. Die Ionenverteilungen verschiedener Modellgeometrien sollen untersucht und mit Hilfe expliziter [[wd:Molekulardynamik|Molekulardynamik]]-Simulationen im Softwarepaket {{ES}} überprüft werden.<br />
<br />
Ansprechpartner: [[Alexander Schlaich]]<br />
<br />
=== Parameterstudien zur Translokation von Biomolekülen durch Nanoporen ===<br />
In den letzten Jahren ist es möglich geworden, künstliche Nanoporen als Sonden in der Welt einzelner Makromoleküle zu benutzen. Bei dem Transport dieser Moleküle durch die Pore spielen elektrostatische Wechselwirkungen eine große Rolle, weil fast alle Biomoleküle (z.B. [[wd:Desoxyribonukleinsäure|DNS]] stark geladen sind. In diesem Projekt soll die Rolle der elektrostatischen Wechselwirkung für diesen Prozess mit [[wd:Molekulardynamik|molekulardynamischen Simulationen]] untersucht werden, um so die wissenschaftliche Grundlage für ein genaues Verständnis dieses Prozesses zu legen. Nur wenn das System gut verstanden ist, kann es letztlich - wie man sich erhofft - zur schnellen Sequenzierung von DNS genutzt werden. Das zugrundeliegende Softwarepaket wird {{ES}} sein.<br />
<br />
Ansprechpartner: [[Stefan Kesselheim]]<br />
<br />
=== Messung der dielektrischen Konstante in einer ionischen Flüssigkeit ===<br />
Mit einem vereinfachten Modell von harten geladenen Kugeln soll im Rahmen einer [[wd:Molekulardynamik|Molekulardynamischen Simulation]] die [[wd:Dielektrizitätskonstante|statische dielektrische Konstante]] bestimmt werden, wie sie aus Messungen mittels [[wd:Dielektrische Spektroskopie|dielektrischer Spektroskopie]] bestimmt wird.<br />
<br />
Ansprechpartner: [[Marcello Sega]] oder [[Axel Arnold]]<br />
<br />
=== Vergröberte Modelle von ionischen Flüssigkeiten ===<br />
<br />
Es existiert eine Klasse von [[wd:Ionische Flüssigkeit|ionische Flüssigkeiten]] mit Schmelzpunkten unterhalb 100&deg;, deren Eigenschaften als Lösungsmittel großes Interesse weckt. Da viele der Mechanismen, die den Charakter der ionischen Flüssigkeiten ausmachen, noch nicht vollständig erklärt sind, können vergröberte Modelle diese Moleküle helfen, entscheidende Faktoren zu identifizieren, um ein besseres Verständnis dieser Lösungsmittel zu ermöglichen. Eine klassische [[wd:Molekulardynamik|Molekulardynamikstudie]] entsprechender Kugelmodelle von Kationen und Anionen soll dazu dienen existierende Modelle zu validieren und gegebenenfalls diese zu erweitern, um einen ersten Einblick in das Prinzip der Molekulardynamik-Simulation, des Coarse-grainings und dem weiten Feld der ionischen Flüssigkeiten zu erhalten. <br />
<br />
Ansprechpartner: [[Florian Dommert]]<br />
<br />
=== Simulation ultrakalte Moleküle mit einem elektrischen Dipolmoment ===<br />
<br />
Ultrakalte Moleküle mit einem [[wd:Elektrisches Dipolmoment|elektrischen Dipolmoment]] lassen sich in einem [[wd:Optisches Gitter (Atomphysik)|optischen Gitter]] einfangen und durch ein elektrisches Feld ausrichten. Durch Manipulation des Gitters und des elektrischen Feldes lassen sich die Wechselwirkungen zwischen den Molekülen beeinflussen. In dieser Arbeit soll mit Hilfe von [[wd:Molekulardynamik|Molekulardynamik-Simulationen]] ein System untersucht werden, in dem mehrere Lagen stark dipolar wechselwirkender Moleküle übereinander angeordnet sind. Ziel der Arbeit ist es, [[wd:Grundzustand|Grundzustand]]sstrukturen zu berechnen, sowie den Einfluß der [[wd:Thermische Energie|thermischen Bewegung]] auf die Grundzustandsstrukturen zu berechnen. Das System ist hierbei gerade noch im Bereich der klassischen Physik. Als Simulationssoftware wird {{es}} zum Einsatz kommen. <br />
<br />
Ansprechpartner: [[Rudolf Weeber]]<br />
<br />
=== Gitter-Boltzmann-Simulationen auf [[wd:GPGPU|Grafikprozessoren]] ===<br />
<br />
Grafikprozessoren (GPUs) sind bei geeigneten Algorithmen mehr als 10 mal so schnell wie ein vergleichbarer konventioneller Prozessor. Zu diesen Algorithmen zählt z.B. die [[wd:Lattice-Boltzmann-Methode|Gitter-Boltzmann-Methode]] für [[wd:Strömungsdynamik|Strömungsdynamik]]. Diese Methode wird in unserer Arbeitsgruppe eingesetzt, um klassische Teilchen mit [[wd:Hydrodynamik|hydrodynamischen]] Wechselwirkungen zu simulieren. Dabei läuft eine [[wd:Molekulardynamik|Molekulardynamik-Simulation]] in der Software {{ES}}, während die Strömungsdynamik auf einer GPU gerechnet wird. Im Rahmen einer Bachelorarbeit sollen Performancemessungen an unserem Code vorgenommen werden, sowie dieser für den Einsatz in Multi-GPU-Umgebungen fit gemacht werden. Ein anderes Thema in diesem Bereich ist die Implementation neuer Randbedingungen, um etwa Mikrokanäle zu simulieren.<br />
<br />
Ansprechpartner: [[Axel Arnold]]<br />
<br />
=== Leistungsvergleich verschiedener Simulationssoftware ===<br />
<br />
Am ICP wird die Simulationssoftware {{es}} entwickelt, mit derene Hilfe [[wd:Molekulardynamik|Molekulardynamik-Simulationen]] durchgeführt werden können. Es existieren verschiedene andere Simulationssoftwarepakte (z.B. [[wd:GROMACS|GROMACS]] oder [http://lammps.sandia.gov/ Lammps]]). Im Rahmen der Bachelorarbeit sollen verschiedene Modellsysteme in den verschiedenen Simulationspaketen simuliert werden und Performancevergleiche zwischen den Paketen angestellt werden. Die Arbeit soll dabei helfen, Schwächen und Stärken der verschiedenen Pakete aufzudecken.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]<br />
<br />
=== Leistungsvergleich verschiedener Algorithmen zur Coulomb-Wechselwirkung ===<br />
<br />
Die Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] nimmt bei [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen einen beachtlichen Teil der Rechenzeit in Anspruch. Über viele Jahrzehnte wurden und werden neue Algorithmen zur Lösung dieses Problems entwickelt. Einige dieser Algorithmen sind im Programmpaket {{ES}} implementiert. Neben kurzem Einlesen in diese Methoden sollen vor allem Simulationen verschiedener Modellsysteme zum direkten Vergleich von Genauigkeit und Performance der Methoden durchgeführt werden. Die Ergebnisse sollen geeignet interpretiert und präsentiert werden.<br />
<br />
Ansprechpartner: [[Florian Rühle]]<br />
<br />
=== Verbesserung des Ewald-Algorithmus für Elektrostatische Wechselwirkungen in {{es}} ===<br />
<br />
Eine Möglichkeit zur Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] in [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen ist die [[w:Ewald summation|Ewald-Summe]]. Obwohl der Algorithmus nicht die schnellste Möglichkeit dafür ist, so eignet sich der Algorithmus wegen seiner hohen Genauigkeit sehr gut zum Vergleich mit anderen, schnellerean aber ungenaueren Methoden. Die Simulationssoftware {{es}} enthält eine Implementation der Ewald-Summe, die bislang allerdings fehlerhaft ist und nur auf einem Prozessor lauffähig ist. Ziel der Bachelorarbeit wäre es, die Implementation der Ewald-Summe in {{es}} zu korrigieren und zu parallelisieren, damit effektive Vergleiche der Methode mit anderen Verfahren angestellt werden können.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]<br />
<br />
=== Verbesserung des Tuning-Algorithmus für P3M ===<br />
<br />
Ein schneller Algorithmus zur Berechnung der [[wd:Coulombsches Gesetz|Coulomb-Wechselwirkung]] in [[wd:Molekulardynamik|Molekularsynamik-Simulationen]] von geladenen Systemen ist der P3M-Algorithmus, der in der Simulationssoftware {{es}} implementiert ist. Der Algorithmus hat zahlreiche Parameter, die seine Genauigkeit und Geschwindigkeit in unterschiedlichem Maße beeinflussen. Zur Wahl des besten Parametersatzes ("Tuning") für ein gegebenes System existiert ein einfacher heuristischer Algorithmus in {{es}}. Ziel der Bachelorarbeit wäre es, das Tuningverfahren zu verbessern. Dazu sollte sich der Studierende zunächst in den P3M-Algorithmus einarbeiten und anhand von Parameterstudien an einfachen Modellsystemen den Effekt der verschiedenen Parameter studieren, um dann den Tuning-Algorithmus gezielt zu verbessern.<br />
<br />
Ansprechpartner: [[Olaf Lenz]]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9140
Thomas Zauner
2011-03-07T09:50:18Z
<p>Intern: /* Realistic computer models for granular porous media */</p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behaviour and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfil certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created using a '''Monte-Carlo''' or '''Discrete-Element-Simulation'''. The packing must fulfil given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centres, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fontainebleau sandstone is shown in figure 1. The continuum computer model can then be discretized at any desired resolution (figure 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Figure 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modelled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Figure 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. At the highest resolution even narrow channels are resolved by more than 20 lattice nodes. This allows high precision flow simulations.]]<br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution of 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
"Numerical modeling of fluid flow in porous media and in driven colloidal suspensions" in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9134
Thomas Zauner
2011-03-04T13:03:40Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behaviour and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfil certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created using a '''Monte-Carlo''' or '''Discrete-Element-Simulation'''. The packing must fulfil given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centres, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fontainebleau sandstone is shown in figure 1. The continuum computer model can then be discretized at any desired resolution (figure 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Figure 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modelled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Figure 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are resolved by more than 20 lattice nodes. This allows high precision flow simulations.]]<br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9129
Thomas Zauner
2011-03-02T15:28:08Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in figure 1. The continuum computer model can then be discretized at any desired resolution (figure 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Figure 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Figure 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are resolved by more than 20 lattice nodes. This allows high precision flow simulations.]]<br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9128
Thomas Zauner
2011-03-02T13:47:21Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are resolved by more than 20 lattice nodes. This allows high precision flow simulations.]]<br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9127
Thomas Zauner
2011-03-02T13:47:00Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are resolved by more than 20 lattice nodes. This allows high precision flow simulations]]<br />
<br />
<br> <br />
<br />
<newline><br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9126
Thomas Zauner
2011-03-02T13:44:38Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are resolved by more than 20 lattice nodes. ]]<br />
<br />
<br> <br />
<br />
<newline><br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9125
Thomas Zauner
2011-03-02T13:44:13Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are resolved by more than 20 lattice nodes. ]]<br />
<br />
<br> <br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9124
Thomas Zauner
2011-03-02T13:42:25Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering [2] of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. ]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9123
Thomas Zauner
2011-03-02T13:41:59Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange. [2]]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium is calculated from the velocity and <br />
corresponding pressure field on the porescale [1,3]. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9122
Thomas Zauner
2011-03-02T13:38:21Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. Empty porespace indicates areas where the fluid is at rest. Only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9121
Thomas Zauner
2011-03-02T13:36:50Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes are analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9120
Thomas Zauner
2011-03-02T13:36:17Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. The resulting model is a continuum model. <br />
The grain centers, sizes and orientations are continuous in space and the grain shapes re analytical defined. An example of such a model for Fountainebleau sandstone is shown in image 1. The continuum computer model can then be discretized at any desired resolution (image 2) for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
== Flow Simulations ==<br />
The '''permeability''' of a porous medium is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of porescale hydrodynamic partial differential <br />
equations. Different numerical methods that solve different hydrodynamic<br />
equations can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is run until a stationary solution has been reached. From this stationary solution the hydrodynamic fields are calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9119
Thomas Zauner
2011-03-02T13:15:44Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used. One option is to use polyhedrons as grain shapes. <br />
<br />
The resulting model then is a continuum model in the sense that the geometry is defined by points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations.<br />
<br />
An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9118
Thomas Zauner
2011-03-02T11:27:56Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration. <br />
Many industrial applications use porous materials. Examples are fuel cells, filtration processes, catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> <br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9117
Thomas Zauner
2011-03-02T11:26:19Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Many industrial applications use porous materials,<br />
such as fuel cells, filtration processes, as catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of spheres is created. The packing must fulfill given constraints such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation and is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9116
Thomas Zauner
2011-03-02T11:18:55Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for fluids.<br />
Physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, have always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Many industrial applications use porous materials,<br />
such as fuel cells, filtration processes, as catalyst in chemical reactions or building materials with special physical properties.<br />
<br />
<br />
The scientific problems I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''. These models are made of several hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and constraints. The associated large computational demand requires efficient and highly scalable parallelized algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Inter:tzneu&diff=9115
Inter:tzneu
2011-03-02T10:55:33Z
<p>Intern: moved Inter:tzneu to Tzold</p>
<hr />
<div>#REDIRECT [[Tzold]]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9114
Tzold
2011-03-02T10:55:33Z
<p>Intern: moved Inter:tzneu to Tzold</p>
<hr />
<div></div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Thomas_Zauner&diff=9113
Thomas Zauner
2011-03-02T10:54:30Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9112
Tzold
2011-03-02T10:54:12Z
<p>Intern: Blanked the page</p>
<hr />
<div></div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9111
Tzold
2011-03-02T09:06:52Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude in lattice units, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9110
Tzold
2011-03-02T09:05:59Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at a resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9109
Tzold
2011-03-02T09:05:42Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone at resolution 5µm. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9108
Tzold
2011-03-02T09:03:08Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
Simulations in stochastic geometries often require very large system sizes to obtain representative solutions. In our investigations, typical sizes of the discretized system are in the range 1024³-4096³ voxel.<br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9107
Tzold
2011-03-02T08:58:46Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9106
Tzold
2011-03-02T08:58:23Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ggg ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9105
Tzold
2011-03-02T08:58:03Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi ggg]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9104
Tzold
2011-03-02T08:57:45Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi] ggg] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9103
Tzold
2011-03-02T08:57:08Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br> </br><br />
<br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9102
Tzold
2011-03-02T08:56:49Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br><br />
<br><br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9101
Tzold
2011-03-02T08:56:25Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure we use a dense packing of spheres is created. The packing must fulfill given restrictions such as density, overlap, size distribution and others. The spheres are later substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shapes.<br />
The resulting model then is a continuum model in the sense that the <br />
geometry is defined by a points in the continuum and polyhedrons with analytical defined shapes, sizes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. Such a continuous computer model can then be discretized at any desired resolution, see image 2, for further analysis and computer simulations.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br></br><br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
physical transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solutions of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' and '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is ran until a stationary solution has been reached. From this stationary solution the hydrodynamic fields can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9100
Tzold
2011-03-02T08:48:13Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications, for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties.<br />
<br />
<br />
The scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that can generate realistic and macroscopic computer models for granular porous media'''. These models will be made of many hundred millions of individual grains whose positions, orientations and sizes must fulfill certain correlations and restrictions. The associated large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Identifying and evaluating numerical methods that allow accurate and predictive calculations of physical properties of porous media'''. These calculations typically require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of possibly <br />
polydisperse spheres is created. The packing must fulfill some given<br />
restrictions such as density, overlap and size distribution and more.<br />
The spheres are subsequentially substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shape.<br />
The resulting model then is a continuum model in the sense that the <br />
microgeometry is defined by a points in the continuum and polyhedrons with analytical defined shapes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. This continuous computer model can then be discretized at any desired resolution for further analysis and computer simulations, see image 2.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br></br><br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
effective transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solution of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' or '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is then carried out long enough to obtain a stationary solution. From this stationary solution the hydrodynamic fields <br />
can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poreflow.avi]] [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9099
Tzold
2011-03-02T08:43:08Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2</sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties (insulating material).<br />
<br />
<br />
Two scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''.These models will be made of many hundred millions of individual grains whose positions and orientations must fulfill certain correlations and restrictions. This large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Evaluating numerical methods to allow accurate and predictive calculations of physical transport properties'''. These calculations usually require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of possibly <br />
polydisperse spheres is created. The packing must fulfill some given<br />
restrictions such as density, overlap and size distribution and more.<br />
The spheres are subsequentially substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shape.<br />
The resulting model then is a continuum model in the sense that the <br />
microgeometry is defined by a points in the continuum and polyhedrons with analytical defined shapes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. This continuous computer model can then be discretized at any desired resolution for further analysis and computer simulations, see image 2.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crosssection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br></br><br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
effective transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solution of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' or '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is then carried out long enough to obtain a stationary solution. From this stationary solution the hydrodynamic fields <br />
can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poreflow.avi]] [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9098
Tzold
2011-03-02T08:42:21Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a natural porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO<sub>2<\sub> sequestration.<br />
Porous materials are also used for many industrial<br />
applications for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties (insulating material).<br />
<br />
<br />
Two scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''.These models will be made of many hundred millions of individual grains whose positions and orientations must fulfill certain correlations and restrictions. This large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Evaluating numerical methods to allow accurate and predictive calculations of physical transport properties'''. These calculations usually require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of possibly <br />
polydisperse spheres is created. The packing must fulfill some given<br />
restrictions such as density, overlap and size distribution and more.<br />
The spheres are subsequentially substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shape.<br />
The resulting model then is a continuum model in the sense that the <br />
microgeometry is defined by a points in the continuum and polyhedrons with analytical defined shapes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. This continuous computer model can then be discretized at any desired resolution for further analysis and computer simulations, see image 2.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crossection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br><br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
effective transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solution of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' or '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is then carried out long enough to obtain a stationary solution. From this stationary solution the hydrodynamic fields <br />
can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poreflow.avi]] [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern
https://www2.icp.uni-stuttgart.de/~icp/mediawiki/index.php?title=Tzold&diff=9097
Tzold
2011-03-01T18:56:24Z
<p>Intern: </p>
<hr />
<div>{{Person<br />
|name=Zauner, Thomas<br />
|status=PhD student<br />
|phone=67652<br />
|room=202<br />
|email=Thomas.Zauner<br />
|category=hilfer<br />
}}<br />
<br />
<br />
<br />
== Research Overview ==<br />
[[Image:bent.jpg |thumb|200px|right| Sandstone is a very common natural porous medium. ©wikipedia]]<br />
<br />
The general field of my research is the '''computational investigations of natural porous media'''. A typical example of such a porous medium is sandstone. <br />
It consists of very small consolidated grains that form a solid backbone but,<br />
due to the space between individual grains, is permeable for many fluids.<br />
Insight into physical transport phenomena of natural porous media, <br />
such as flow rates, trapping behavior and prediction <br />
of effective transport coefficients, has always been of great practical <br />
interest for the oil and gas industry and has currently drawn public<br />
attention in the context of CO2 sequestration.<br />
Porous materials are also used for many industrial<br />
applications for example in filtration processes, as <br />
catalyst in chemical reactions or building materials with specially<br />
physical properties (insulating material).<br />
<br />
<br />
Two scientific problems that I address in my work are:<br />
<br />
*''' Developing algorithms that generate realistic and macroscopic computer models for granular porous media'''.These models will be made of many hundred millions of individual grains whose positions and orientations must fulfill certain correlations and restrictions. This large computational demand requires highly efficient parallelized computer algorithms. <br />
<br />
* '''Evaluating numerical methods to allow accurate and predictive calculations of physical transport properties'''. These calculations usually require numerically solving partial differential equations within a chosen discretization scheme and at a specific resolution or order of accuracy.<br />
<br />
<br />
== Realistic computer models for granular porous media ==<br />
In the reconstruction procedure a dense packing of possibly <br />
polydisperse spheres is created. The packing must fulfill some given<br />
restrictions such as density, overlap and size distribution and more.<br />
The spheres are subsequentially substituted by more complex geometrical <br />
objects determined by the shapes of the grains used in the<br />
specific model. One option is to use polyhedrons as grain shape.<br />
The resulting model then is a continuum model in the sense that the <br />
microgeometry is defined by a points in the continuum and polyhedrons with analytical defined shapes and orientations. An example of such a model for Fountainebleau sandstone is shown in image 1. This continuous computer model can then be discretized at any desired resolution for further analysis and computer simulations, see image 2.<br />
[[Image:all.png |thumb|400px|left| Picture 1: Three dimensional rendering of a model for Fontainebleau sandstone. The model contains over 1.2 million quartz grains. Each grain is modeled as a polyhedron. A crosssection is shown in orange.]]<br />
[[Image:muCT_ani.gif |thumb|300px|right|Picture 2: Two dimensional crosssections of the discretized model.The sidelength of the crossection is L and the resolution a. The porespace is black and the grains are gray. A the highest resolution narrow channel are solved by more than 20 nodes. ]]<br />
<br />
<br><br />
<br />
<br />
== Flow Simulations ==<br />
A porous mediums '''permeability''' is an example of a <br />
effective transport parameter. It describes the mediums ability to <br />
transmit fluid flow through it. Using '''Darcy's law''' the permeability<br />
of a porous medium can be calculated from the velocity and <br />
corresponding pressure field on the porescale. These fields <br />
are solution of hydrodynamic partial differential <br />
equations describing fluid flow on the porescale. Many different<br />
numerical methods that solve different hydrodynamic equations<br />
can be used to obtain the velocity and pressure field.<br />
Possibilities are '''Navier-Stokes simulations''' or '''Lattice-Boltzmann simulations'''. Our Lattice-Boltzmann implementation, for example, numerically solves the Boltzmann equation using a '''transient explicit finite-difference scheme'''. The simulation is then carried out long enough to obtain a stationary solution. From this stationary solution the hydrodynamic fields <br />
can be calculated. <br />
<br />
[[Image:poreflow1.jpg|thumb|550px|center| Very small subvolume (128³ voxel) of a sandstone. The porespace-matrix interface is shown as a mesh. The velocity magnitude, as calculated by a Lattice-Boltzmann simulation, is shown within the porespace. Areas of slow flow are blue, fast flow is shown in red. An empty porespace indicates areas where the fluid is at rest. It can be seen that only a small portion of the porespace contributes to the mass transport. [[Media:poreflow.avi]] [[Media:poremovie.avi]] ]]<br />
<br />
<br />
== Publications ==<br />
<br />
[1] A. Narvaez, T. Zauner, F. Raischel, R. Hilfer, J. Harting, “Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations”, Journal of Statistical Mechanics, P11026, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/LB_JStat08.pdf Preprint]<br />
<br />
<br />
[2] S. Grottel, G. Reina, T. Zauner, R. Hilfer, T. Ertl, "Particle-based Rendering for Porous Media", SIGRAD, 2010, [http://www.icp.uni-stuttgart.de/~zauner/publications/sigrad_2010.pdf Preprint]<br />
<br />
[3] J. Harting, T. Zauner, R. Weeber, and R. Hilfer<br />
Numerical modeling of fluid flow in porous media and in driven colloidal suspensions<br />
in High Performance Computing in Science and Engineering '08, edited by W. Nagel, D. Kröner, M. Resch, Springer ,2008. [http://www.icp.uni-stuttgart.de/~zauner/publications/HPC08.pdf Preprint]</div>
Intern