Hi I have a problem about rate of convergency of a code I used vorticity velocity with mack's staggered grid . both transiant and steady solution have same low rate of convergency . I solve a 2 lapplace equation for u and v velocity and a equation for vorticity . I can explain more about it if you like to help me .

thanks for paying attention .

Convergence depends on how convection dominate (how large is Re), how nonhomogenious the grid is. Numerical solution of Possion equation can be accelerated by a multigrid method in general.

hello dear friend thanks for paying attention . I use point jacobi for both poissons' equation and for solving vorticity equation too . when I compare vorticity calculated from curl of momentum equation ( solved by point jacobi) with vorticity calculated from definition , I find large diffrence between these two value .

I use suitable grid and reynold's number but I think that there is something I didnot consider. I wrote a code using SIMPLE algorithm it converges so fast but when I compare these two codes I find out that I it too slow , but I have heard that vorticity velocity method is faster than SIMLPE alg .

I'll be glad to know you'r idea . please help me . thank you.