We have encountered a major problem using a commercial CFD code models utilizing standard porous media models by Brinkman. The Brinkman model, as you know, does not contain inertial terms and hence it grossly errs in outflow direction if the inflow is highly non-uniform or at an angle.

Anybody knows of commercial CFD codes which use better models?

Thanks.

You'll probably get some response here.

But you might also want to check the discussion groups for the major codes.

http://www.cfd-online.com/Forum/

Most of the major players are discussed in those groups.