Hauptseminar Porous Media SS 2021/Theory of diffusion
- Theory of Diffusion
- Veit Kilian Kutzner
- Alexander Reinauer
In this talk an introduction to the description of diffusion and transport is given. For this a short introduction to hydrodynamics is given with the focus on characterizing the flow with dimensionless numbers including the Reynods, Mach ,Capillary and Knudsen number. After that the contributions to the reaction-diffusion advection equation are discussed and the Peclet number is introduced. Finally the Onsager theory for transport coefficients is presented and the differences between the self, collective and transport diffusion are highlighted. This should also include the connection to Fick’s law of diffusion, the mean-squared displacement and the Green-Kubo relation to determine the diffusion coefficients from particle trajectories.