Media with low porosity
 

Hi,

I have a situation where the flow runs through an annulus channel, where the outer boundary is a wall and the inner boundary is a solid medium with porosity ~30%. This medium is followed by another layer of even lower porosity. In reality, mass diffuses through these two porous media, and convective transport is ~ zero. If I were to use the "Porosity" tab in Star GUIde to model these porous cells, I calculate extremely high values for alpha and beta constants. (e.g. my lowest values are alpha=9.618e+04 and beta=5840.1)

After running a simulation, the results show effectively no mass flow in the inner (porous) media.

I guess I am having trouble with the diffusion part of this process... Does anyone have experience with this? Where can I make adjustments to account for the diffusion process?

Thanks, Emmanuel