I’m also a fellow LBM-coder although still working on learning the basics of the method. Currently I’m doing my Master Thesis on simulating flow through a porous media and I would want to calculate some gas transport properties as permeability and diffusivity. Has anyone any good ideas how to calculate these?
From articles that I read, I figured that permeability can be calculated from Darcy’s law, using a pressure-driven flow. How should the boundary conditions at the domain boundaries be defined in order to get a correct result? Right now I have a pressure driven flow in x-dir, and the domain is bounded by walls in z- and y-directions, but i figured since the permeability is a tensor, we need to allow a flux in z and y aswell?
For diffusivity, I would want to find the material parameter epsilon/tau (porosity/tortousity). Porosity is quite easy to find from the structure, but I’m not really sure how to obtain the tortousity. Shouldn’t it be possible to calculate it directly from the resulting velocity field?
Method that I’m using is the D3Q27, BGK SRT with bounce-back
Thank you =)