Which momentum equation for porous media is correct?
Through checking out the momentum equations for porous media from the user’s guide in Fluent 6.2, 16.1, 19R3, I found out that the viscous and inertial force terms in the equations are different. And the user’s guides all mention that all the equations are using the physical velocity formulation, so could you help me to explain why they are different, and which equation is correct? The attached are the momentum equations.
In addition, when the same viscous coefficient and inertial coefficient are loaded into the model through UDF, and all the settings in the models are same, however, the results are far different by using Fluent 16.1 and 19R3. I guess this difference is related to the momentum equation. Thanks in advance.