catching shedding vortex in 2d analisys
 

Hi!
i'm a cfd newbie and i'm trying to solve a tipical cfd problem: catching shedding vortex (shown in the figure below) generated by a steady flow around a circle (2D) with Fluent

http://img11.imageshack.us/img11/294...hedding.th.jpg

i'm trying to solve it with a k-eps model (unsteady analisys). for the mesh i use a boundary layer around the circle and a triangular growing size mesh all over, (more thick in the tail) is this correct?
and about the wall condition, do i have to use one?

thank you very much!