Unreal vortices in NACA0012 at high angle of attack
 

Hi friends,
I am simulating steady state 2D naca0012 airfoil at high angle of attack. I made the C type grid with 50C*50C dimensions with blunt trailing edge. Everything is good untill when I am trying to simulate it at higher AOA like 16its showing me the vorticity near the two face connections at the trailing edge which seems to be quiet unreal. anybody knows how to fix the problem.
I am attaching the pictures of the airfoil vortices at AOA 16.
http://img32.imageshack.us/img32/3418/62143078.jpg
http://img6.imageshack.us/img6/1402/16041239.jpg
http://img7.imageshack.us/img7/9769/92423939.jpg
http://img6.imageshack.us/img6/3161/15773007.jpg

Case file link:
http://www.4shared.com/file/13324788...rfoil0012.html

It looks like the trouble is grid-generated because both of those regions have high aspect-ratio cells. I've seen similar results in some of my cases. Try adapting the grid in those regions, either in FLUENT or your grid generator. FLUENT would probably be better, so you only adapt the cells in question instead of making the entire grid finer.