[Natalie2210]

Dear Foamers,

I encounter a strange phenomenon when simulating flow through porous media with the porousInterFoam solver.

The following scenario is considered: The rectangular 3D simulation domain consists of three different layers which differ in their permeability. At one side, the fluid is injected, traveling through the domain in x-direction and leaving it at the other end. tHe driving force is a pressure difference between the inlet and outlet.
The flow through the layers with high permeability (top and bottom) is faster than it is in the low permeability layer (in the middle). I expect the developement of a through thickness flow (gravity is turned on) to fill the middle layer faster than it would be by just the pressure difference. Nevertheless, I see a small channel forming which is depicted in one of the attached screenshots. Slicing in x-normal direction through the domain and having a look at what is inside I do see that a very small pressure difference is present, however, the entire filling in through thickness direction happens very slowly, much slower than I would expect. Do you have any thoughts on what might be causing this or how I can achieve complete filling?

Thank you a lot,
Natalie