Hi all, I am solving 3D air
 

Hi all,

I am solving 3D airfoils (NACA 0016 @ 0 degrees) using rhoSimpleFoam. I am comparing different meshes. So far I have compared a constant surface mesh with a mesh refined at the trailing and leading edges. When I run liftDrag, i get a higher drag co-efficient for the mesh that is refined.

My friend did the same comparison using an incompressible solver in fluent. He found the refined mesh gave a lower drag co-efficient as it better resolved the forward facing pressure at the leading edge of the airfoil (which seems to make sense). My question is this:

Does anyone have any ideas as to why the results are opposite in the compressible solver? The two domains are a slightly different size, could this have an effect (although both domains should be sufficiently large)?

Thanks very much for any thoughts.

Ryan