Low permeability medium simulation using pimpleFoam
 

Good night,

I've been trying to simulate laminar flow of a fluid through a porous medium (hydrogel) with a permeability of around 10^(-15) m². I can reach the 10^(-12) mark, but when I get past that the solution simply does not converge. In fact, the only way I got the pressure field solution to converge in the first place was by using the PIMPLE algorithm with a large number (~100) in the nOuterCorrectors. The solver I am using for pressure is GAMG. I am glad I was able to achieve this but the solution is still off by a 3 order of magnitude difference. To make matters worse the geometry is quite complex. I tried to reduce the timestep down to a millisecond with no success. The Courant number explodes after some iterations. Does anyone know how to solve this problem? Should I provide more information? Perhaps increasing or decreasing the level of refinement of the geometry could help?

Thanks in advance.