code_saturne User's Forum

Dear Users,

I'm quite new with the use of Code_Saturne.
I'm studying a steady flow in a 3D flat plate with simple boundaries conditions (Dirichlet at the inlet and at the bottom, Neumann for the other parts).
My trouble today is to extract the heat exchange coefficients located at the bottom of the plate (divided in several zones).
I guess I have to ask to Code_Saturne to calculate these values thanks to a subroutine which can give me an array containing them, but I don't know the name of this subroutine, neither how to extract the heat exchange coefficient. Is it in the RA array ? Or somewhere else ?
Moreover, I'm wondering if it is possible to see the coefficients in Paraview for example ?

Thanks a lot for your help.
Regards,

F.P

Dear Florian,

If by heat exchange coefficient you mean the heat transfer coefficient or "h" (W/m^2K), then Code_Saturne does not calculate this variable directly. You will need to do this in the routine cs_user_extra_operations and use an equation along the lines of:

h = q/AdT

on a cell by cell basis for a given boundary in order to generate a matrix of h based on local flow conditions or an average value for the given boundary.

The user routine cs_user_extra_operations-energy-balance located in SRC/EXAMPLES is a good place to start as this routine will give you some ideas as to what Code_Saturne variables you will need to use.

Concerning the plotting of these variables in Paraview, I'll have to have a think about that one.

Best regards,

Brian Angel.

Dear Brian,

Thank you for your answer,
It is effectively "h" I would like to extract.
However, I'm looking for the routine cs_user_extra_operations without success, so I'm wondering if I'm using the correct version of Code_Saturne (I have the 2.0.1 version).
The matter is that I can't easily update Code_Saturne to the 3.0 version. Maybe it's nevertheless possible to create and to insert the routine cs_user_extra_operations in the SRC/base folder ?

Best Regards

F.P

Hello Florian,

The routine I recommended is for v3.0 of CS. You will not be able to use the v3 routine with that of v2 without a lot of difficulty and having to modify arguments, variables, etc. I'll have a look here and let you know what routine you should use for v2.

Best regards,

Brian Angel.