Porous media and convergence

A.Joshi

If the porous media is inclined to the global coordinate system and we set the plane with plane tool and apply the coefficients for porous media. Flow is only one directional. There are multiple fans blow air into the porous media. The solution doesn't converge, fans converge to reverse flow. I have to first solve laminar flow and then turbulence and then porous media. This takes very long time. I'm using very large value of coeff. for the direction other than normal to flow. But with large value the flow doesn't converge, but it converges as I reduce it to the coeff. value similar to the flow direction. Any ideas how to solve the problem in one go???

Thanks, Ajoshi