Hello, for my studywork I simulate the flow through a centrifugal pump. I have four fluid-zones, 1 rotating, three static. During the Iteration, at first, all values seam to converge. When the errorvalue reaches about 0.009 it begins to increase again. Can somebody of you tell me what are possible reasons for that and what I can do now to solve the problem? Thank you... Melanie Kramp

Please check the models -> solver, choose the method which is suitable for your calculation. If state is unsteady, check the time step, grid size as well. If the time step or/and grid size are quite large, the solution will oscilate. Good luck,

Melanie, First of all, do 10 iterations and check your mass flux at the inlet is everything looks right. Then from time to time stop your calculation and check the contour of turbulence and velocity to see where you calculation is diverging, is it in a particular area of you domain or is it general. Let us know !

My first thought would be - did you scale your domain, i mean you may have done you mesh in gambit in "in" and leave in "meter" in your calculation. It could be also because of you MRF set-up. Good luck