[xck1986]

Dear FoamUsers,
I am now using the compressible Solver rhoSimpleFoam (steady state case) to simulate a valve.
But I always have the problem of the residuals oszillation, especially for the pressure. see the residual figure in attachment.
I have try to modify the relaxtionfactor for every variable, but it still has oszillation.
Is that possible that the problem was linked to my mesh? Because some boundary elements in my mesh is very small.
The whole case foleder can be found under the fokllowing link:
http://www.youzihui.com/klaus_upload...uestion.tar.gz
Thanks a lot!

[fletc900]

Hi there. I've had CFD simulations before (not in OF) in which the residuals would oscillate like yours...that doesn't specifically mean that your simulation has not converged. It depends on how OF is calculating the residuals. Are the residual calculations in OF normalized by the average first N iterations? This is something to investigate...

Have you checked other measures for convergence? Such as mass flow rate in - mass flow rate out? Does this value oscillate too?

Cheers

[aerothermal]

xck1986,

I agree with fletc900.
what are your results for x,y,z forces or moments?
are they converged?

regards,

guilherme