Search found 4231 matches

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: 3
Views: 1158

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: 92

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 the libsy...
by Yvan Fournier
Tue Jun 17, 2025 12:40 pm
Forum: code_saturne usage
Topic: MPI Error with CS/Syrthes coupling
Replies: 4
Views: 92

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: 5517

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: 90

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 m...
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: 949

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 relat...
by Yvan Fournier
Thu Jun 12, 2025 12:24 pm
Forum: code_saturne usage
Topic: Question about the convergence of LES calculations
Replies: 3
Views: 949

Re: Question about the convergence of LES calculations

Hello, What type of meshes do you use ? LES in code_saturne can be quite sensitive to mesh quality and regularity. In a similar way, though centered convection schemes are needed for the conservation of energy, a very small portion of upwind (2%) might help stabilize the computation. Best regards, Y...
by Yvan Fournier
Thu Jun 12, 2025 1:57 am
Forum: code_saturne usage
Topic: y+ value for k-e wall function with high roughness
Replies: 3
Views: 1158

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

Hello, The guidelines are a good starting point, but need updating, and do not take into account some newer options such as the all-y+ law (in k-omega) or low-Reynolds models. I do not think they were written with the rough law model in mind, as the roughness adds an amount of user modeling, and the...
by Yvan Fournier
Tue Jun 10, 2025 1:30 am
Forum: code_saturne usage
Topic: SIGSEGV signal issue
Replies: 1
Views: 1210

Re: SIGSEGV signal issue

Hello, It is not possible to determine whether this is due to an issue in the code or in you user-defined functions, so you need to: - ideally, run this under under a debugger on your side, to get more details - otherwise, post you user-defined files. Also, v7.0.2 is not up to date, so you should up...
by Yvan Fournier
Fri Jun 06, 2025 12:20 pm
Forum: code_saturne usage
Topic: Groundwater Module - Neumann Boundary Condition Issue
Replies: 1
Views: 1638

Re: Groundwater Module - Neumann Boundary Condition Issue

Hello, Do you also have some user-defined functions ? Checking with a colleague developing this, your Van Genuchten ks value seems a bit high (in clay, it would be closer to 1e-2 or lower). Also, the groundwater module used in the v8.0 GUI is obsolete, and replaced by the CDO-based module in v9.0. (...