About Solver Overflow

Felix

Hello everyone,

I know this question as been treated in many previous posts but I never found a clear answer. I am actually simulating flows in elbow draft tubes and often get the "LINEAR SOLVER OVERFLOW". As I understand it, it is really a mesh issue (in my case at least) as two different meshes behave differently.

I give you an example. One of my tetra mesh was running well but the Y+ value was too large so I refined the near-wall prism layer. The calculation crashed after about 15 iterations and the total pressure loss between the inlet and the outlet had reached 10^15 or so. I also had the same problem with Hexa meshes.

Does anyone have a valuable experience regarding this problem? I suspect large aspect ratios to be part of the answer but then how can we respect the requirements on Y+ (I'm using SST) ? Also, calculating in double precision didn't help.

I'm sure this post can be helpful to help many of us. Regards,

Felix