Steady-Compressible flow

[stephio_maf]

Hello,

I would like to know if in CS 5.0, it is now possible to set a Steady-compressible case (in my case steam) using the GUI. Is it possible to get a guideline?

Stephane

[Yvan Fournier]

Hello,

There was no development in that regards to my knowledge.

Did you test / try to run ?

Regards,

Yvan

[stephio_maf]

Hello,
when using the GUI, the compressible model is not available with "steady flow" algorithm selected .

Steph

[StandardRANSUser001]

Dear Yvan and Steph,

It has been quite a few years since you have had this conversation, and I wanted to enquire whether there has been an update on this functionality. I am developing a case on CS 8.0.3, and the steady option is unavailable for the compressible solver in the GUI. Can this option be accessed without the GUI?

Any assistance on this would be greatly appreciated.

Best regards,
Sean Hanrahan

[Yvan Fournier]

Hello,

I do not think there has been any new development in this regard, though there has been work on another compressible model which may have different constraints.

Did you try forcing the pseudo-steady algorithm using a user-defined function (I.e. cs_user_parameters) ?

Best regards,

Yvan

[StandardRANSUser001]

Hi Yvon,

Thanks for your help on this.

Could you please confirm that I have correctly modified the cs_user_parameters.c file.

void
cs_user_parameters(cs_domain_t *domain)
{
cs_time_step_options_t *time_opt = cs_get_glob_time_step_options();
time_opt->idtvar = CS_TIME_STEP_LOCAL;
}

For others reading this post, there is a good description of pseudo-steady algorithm in Essentials of Computational Fluid Mechanics, by Jens-Dominik Műller, page 65.

I have a question about the implementation of the pseudo-steady algorithm in Code Saturne.

Starting with your previous comments here: viewtopic.php?t=2558
You have mentioned that the pseudo-steady algorithm keeps pushing the time-stepping to a CFL number of 1. Does this mean that the CFL number defined in the GUI is not used in this calculation, or does this mean that the user defined CFL number correspond to the time-steps taken from this algorithm? Which time settings (in the GUI) are used by this algorithm?

Finally, I would just like to confirm whether CS_TIME_STEP_STEADY can be used for compressible flows without the GUI?

Best regards,
Sean Hanrahan