code_saturne User's Forum

Dear all,

I'm currently performing some tests related to atmospheric dispersion using scalars for the follow up of dispersion.

When switchching from KEPS to RIJ turbulence model, I don't have any problem. If willing to change the turbulent flux model of my scalars from SGDH to DFM, I need to add the variance for my scalars (done) but I now have an error related to the volumic thermal expansion coefficient Beta that I did not have previously. When looking at the GUI, I don't see any Beta coefficient. Any suggestion about what I should do in order to fix this problem?

@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@
@ @@ WARNING : ABORT IN THE PHYSICAL QUANTITIES COMPUTATION
@ =========
@ INCOHERENCY BETWEEN PARAMETERS and the volumic thermal
@ expansion coefficient Beta
@
@ The density has been declared variable (IROVAR=1) but
@ the value of Beta has not been modified
@ in GUI or cs_user_physical_properties
@
@ The calculation will not be run
@
@ Check the interface or cs_user_physical_properties.
@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Kind regards

JCo

Hello,

the beta coefficient is defined by a field that is activated automatically with this model, but whose values must be set by the user. It is set by default to -1 so that if it is not defined, you get the error message you observed (rather than having no error message but not computing what you expect to be computing).

To set the values of that field, you need to do it in a user-defined function, such as cs_user_physical_properties.

Note that the DFM model is quite recent and not used much, and though it passes a few simple test cases, it may not be very stable yet.

Best regards,

Yvan

Thanks a lot for these feedbacks Yvan.

Hello again,

I was considering that DFM would be more suitable than SGDH in case I use RIJ ssg turbulence, am I wrong on this point?

Kind regards

JCo

Hello,

I have suggested to some colleagues more expert in.the turbulence modeling of the code to check this post... I'll ping them again.

Best regards,

Yvan