[driu]

Dear Foamers,

I have recently started using OpenFOAM and gradually ran into some convergence issues that I cannot tackle myself.

What I am trying to do is to compare my OpenFOAM simulation with a simulation done in ANSYS CFX.
The case is a swirl induced by turning vanes. Please find attached the geometry domain screenshot.

I am running the case with simpleFoam using kOmegaSST turbulence model.
Please see the case files attached or let me know if you require any specific details.


Now the problem is convergence in my OpenFOAM simulation. As soon as I try using second order divergence schemes, I get problems with convergence. I am quite lost where the problem is.

Please see the residual plot attached.

For comparison, the residuals in CFX go down below 1e-6 (RMS) or 1e-3 (max). I am using ‘High resolution’ Advection Scheme setting there.

I would really appreciate any guidance on this and apologies if it’s just another beginner level question.

Is there anything obvious I should check first or anything obviously wrong in the setup?

Many thanks for your time!

Kind regards,
Audrius