Convergence for axisymmetric flow

bl201

Hi everyone,

Question about axisymmetric flow: I'm using a 2-D planar flow solver that I want to modify to handle axisymmetric geomerty.

I've derived the NS equations in cylindrical coordinates, and coded the source terms (implicitly), but the solver does not converge anymore. Running 1st or 2nd order, inviscid or viscous, nothing can make it to converge.

Actually it does converge for a static-to-stagnation pressure ratio of .35, which is not very interesting as the flow separate right after the throat of the nozzle. No run with a lower pressure ratio converged.

Any solution to improve convergence ?

bl201

ps: I'm quite a beginner in CFD and on this forum; thanks for your help...