How to enable clipping of pressure and velocity in CS 5

[JonasA]

Hello everyone,

I am running a simulation of a pump in a complex geometry in Code Saturne 5.0. I try to compute a steady state with the frozen rotor Turbomachinery module.

The clipping section of equation parameters in the numerical parameters only permits clipping of temperature and user defined variable, is there a way to access clipping for the other variables such as pressure and velocity?

Thank you very much!

[Yvan Fournier]

Hello,

I'm not sure about velocity, but you can't clip pressure, which has a specific role in incompressible flow resolution algorithms.

Regards,

Yvan Fournier

[leguichet]

Hello Yvan,

In the commercial software such as FLUENT, they automatically re-set the "too large" values of the velocity and turbulence scalars like k or epsilon, when the mesh quality is not as high as we wish, to facilitate the convergence of the solution.

Is that possible to do the clipping for k-epsilon and velocity in CS 5.0.8? And how? In which routine?

Kind regards

Zhenaln

Hello,

I'm not sure about velocity, but you can't clip pressure, which has a specific role in incompressible flow resolution algorithms.

Regards,

Yvan Fournier

[Yvan Fournier]

Hello,

k and epsilon are clipped automatically, based on allowed ranges (but occurrence of clipping is a sign of "not-so-well behaved" case. Velocity and pressure can not be clipped cleanly, as that basically changes the velocity-pressure coupling.

You can always try changing the velocity between 2 time steps in cs_user_extra_operations, but this is not definitely not recommended...

Best regards,

Yvan