I am simulating flow past circular cylinder using method of Artificialcompressibility proposed by Chorin. I have problem in implemeting outflow BC.

I used traction free propoesed by Gresho -1. p+2*mu*par*Un/par*n

2. (u, v )extrpolated and p=p_infinity

3. convective BC

but no satifactory result

can any one help me.

I can send the output file so that one can get insight of the problem.

Thanks

Khan

I use divergence-free finite elements with no pressure gradient term and no outflow boundary condition. It works just fine.