I’m doing simulation of airflow through porous media. According to the charactheristics of the flow and the geometry, the flow is turbulent, so after doing some simulations, the physics chosen was k-epsilon Low-Re, because of the wall treatment (Low Re). Geometry is a 2D rectangle representing a long tube with the porous bed in the middle of it.
I included a volume force in order to simulation porous media. At flow conditions, the equation that represent it is Ergun Equation ( that could be expressed as Forchheimer eq). My implementation was as simple as :
So, when I defined a horizontal cut plane in the middle of the bed to see velocity profile, I found a problem because, a velocity peak is shown at each side, near to the wall (fig 2 and fig 3). Since properties are isotropic, there no reason for this, so, it's simply wrong.
I think it is not a boundary layer problem because I simulated it when having a fully developped flow and with 12 boundary layers (as default), shown at fig 1. Minimum mesh quality is 0.45, which I think is not so bad. I tried also using laminar flow conditions and Fluid and Matrix Properties as default which uses Darcy's Law, but the profile was similar.
Has anyone had this kind of problem? Am I missing something? How could I overcome this problem??
thanks in advance, Jhoan G.