Reply To: Incorrect velocity streamlines and observed velocities profile

[Rob]

Fans aren't that easy to model, and you may find the supply side flow patterns alter the results: I'd typically test in open space and the shroud is then dependent on the fan. Re surface mesh, once you have inflation etc you're more interested in the resolution across the blade (chord?) and then use that for the length. I don't have numbers for that, and can only point you to review literature. That high level of resolution may then need to be maintained (or at least grown slowly) into the wake region to avoid numerical diffusion. 

Core count is more for speed. RAM determines model size, coupled with poly mesh and double precision will want 3-4GB per million cells.