Search found 4235 matches

by Yvan Fournier
Wed Jul 09, 2025 9:22 pm
Forum: code_saturne usage
Topic: y+ calculation on rough walls
Replies: 1
Views: 39

Re: y+ calculation on rough walls

Hello,

This is probably computed in src/base/clptrg.f90. So it may be interesting to check/log/print the intermediate values used in its computation.

I'm not sure about the theory part, as there is both a legacy rough wall model, and a new one (continuous "smooth/rough" model). The newer model ...
by Yvan Fournier
Wed Jul 02, 2025 7:29 pm
Forum: code_saturne usage
Topic: Thermal transfer with Syrthes
Replies: 3
Views: 3750

Re: Thermal transfer with Syrthes

Hello,

1) The quantities should only be on boundary faces. Do you have separate writers for volume and boundary faces ? If not, using "extract block" under ParaView might help separate them.

2) Yes, this sign is chosen from a "finite volume" rather than user perspective. A negative flux means heat ...
by Yvan Fournier
Wed Jul 02, 2025 12:55 am
Forum: code_saturne usage
Topic: Thermal transfer with Syrthes
Replies: 3
Views: 3750

Re: Thermal transfer with Syrthes

Hello,

It may be interesting on the code_saturne side to activate the visualization output of the thermal fluxes at walls (and wall temperature), to see what amount of heat exchange you have at the interface.

Depending on the mesh and turbulence model, the heat exchange might be underestimated ...
by Yvan Fournier
Tue Jul 01, 2025 11:19 am
Forum: code_saturne usage
Topic: Syrthes coupled simulation crashes
Replies: 3
Views: 4086

Re: Syrthes coupled simulation crashes

Hello,

The logging of the space dimension seems to be a bug, but I suspect your issue is that you have a 2D domain in Syrthes, and a 3D one in code_saturne. In the 3D disks example (whose reference setup should be updated), the "2D projection" option in the conjugate heat transfer section is set ...
by Yvan Fournier
Tue Jun 17, 2025 4:17 pm
Forum: code_saturne usage
Topic: y+ value for k-e wall function with high roughness
Replies: 5
Views: 14039

Re: y+ value for k-e wall function with high roughness

Hello,

I meant that the choice of the roughness value can in itself be based on some user modeling choices. I was thinking mostly of the atmospheric cases where roughness can represent vegetation, which is accounted for in a simplified (i.e. modeled) way as a form of roughness.

Best regards,

Yvan
by Yvan Fournier
Tue Jun 17, 2025 4:14 pm
Forum: code_saturne usage
Topic: MPI Error with CS/Syrthes coupling
Replies: 4
Views: 6119

Re: MPI Error with CS/Syrthes coupling

Hello,

I mean that Syrthes can compile its own OpenMPI library as an external dependency, but this does not seem to be the casde here.

But you may be missing a setting in the syrthes-install/setup.ini file : you should have:


ple_use=yes
syrthescfd INSTALL=yes


Otherwise, you will be missing ...
by Yvan Fournier
Tue Jun 17, 2025 12:40 pm
Forum: code_saturne usage
Topic: MPI Error with CS/Syrthes coupling
Replies: 4
Views: 6119

Re: MPI Error with CS/Syrthes coupling

Hello,

Are you sure your code_saturne and Syrthes builds use the same MPI installation ? Mismatched MPI libraries could explain the observed behavior. Since the Syrthes install script builds its own MPI library by default, this could happen if you are not extra careful.

Best regards,

Yvan
by Yvan Fournier
Tue Jun 17, 2025 12:33 pm
Forum: code_saturne usage
Topic: Restart save frequency
Replies: 7
Views: 9647

Re: Restart save frequency

Hello,

Not by default, but if you use the cs_restart_set_n_max_checkpoints function in.your settings (in cs_user_parameters) you should be able to do this (with an additional subdirectory per checkpoint time).

Best regards,

Yvan
by Yvan Fournier
Tue Jun 17, 2025 12:27 pm
Forum: code_saturne usage
Topic: fortran routine for v8
Replies: 1
Views: 3980

Re: fortran routine for v8

Hello,

You can use iso_c_bindings to provide a C API to your Fotran code, and call that from the standard C user function.

If your Fortran code does not depend on too many internal code_saturne structures, or those can be passed as arguments, this should even continue to wrk after v9.0. If you use ...
by Yvan Fournier
Fri Jun 13, 2025 6:30 pm
Forum: code_saturne usage
Topic: Question about the convergence of LES calculations
Replies: 3
Views: 4541

Re: Question about the convergence of LES calculations

Hello,

Sometimes, just a few pinched cells can cause issues, but It is hard to tell without looking at your mesh.

Would it be feasible an LES on a simpler mesh, or a truncated version of this one in which you have only the "good" cells, to see if this works better, or if the issue is related to ...