Converge in Dense meshe, Diverge in less mesh, but correct answer in less mesh!?!?
 

Hi again,

I am working flow over cylinder 2D with fluent and my purpose is that show the vortex shedding behind the cylinder.

I meshed the domain 2 times. First I meshed dense and my solution converged but i couldnt see the vortex shedding. I should mention the my fluid is air and the velocity is 0.002 so that my Re=137.

The solver is Laminar, steady and etc.

next time, I changed my meshing and change to less mesh than before after that my solution didnt converge but i saw the vortex shedding behind the cylinder.

I attached the figures of my solution in both cases and my meshes in both cases.

does anyone know the reason of that?

Thanks in advance.