Hi all;
I am solving a 3D Poisson Equation by linear multigrid method. It works fine when dx=dy=dz. But when the size of dx, dy or dz are not equal, I get instability problems. I have the same problem in 2D and also with FAS-Multigrid. Is it a usual case in Multigrid? I will be very pleased is somebody help me to fix this problem.
Thanks in advance.