Search found 4295 matches

by Yvan Fournier
Thu Apr 16, 2026 5:53 pm
Forum: code_saturne usage
Topic: How to properly use LTS
Replies: 5
Views: 4759

Re: How to properly use LTS

Hello,

1) I am not sure how this is computed. I will check, but will probably not be able to look at this in detail before 10 days or so.

2) Without this parameter, I assume the risk is to have very strong variations in some matrix coefficients, but I am not sure we ever tested the feature without ...
by Yvan Fournier
Wed Apr 15, 2026 1:38 pm
Forum: code_saturne usage
Topic: How to properly use LTS
Replies: 5
Views: 4759

Re: How to properly use LTS

Hello,

I would be surprised if we did not use a consistent momentum interpolation, though I am not an expert in that part of the code.

For 1), yes, the Fourier number may be involved in the time step computation for the fluid region. This may cause issues in some cases where turbulent models lead ...
by Yvan Fournier
Tue Apr 07, 2026 11:55 pm
Forum: code_saturne usage
Topic: Water wheels
Replies: 4
Views: 6213

Re: Water wheels

Hello,

This topic should be in "general usage", as it contains questions relative to code usage, and not discussions on development, roadmap, .... exxcept for the question about neptune_cfd.

AS for the question, neptune_cfd is provided to some industrial or academic partners, and this is subject ...
by Yvan Fournier
Tue Apr 07, 2026 11:31 pm
Forum: code_saturne usage
Topic: time step setting routine (former varpos.f90) in v9?
Replies: 1
Views: 3905

Re: time step setting routine (former varpos.f90) in v9?

Hello,

In v9.0, ischtp corresponds to 'cs_glob_time_step->time_order' in C (and is still called ischtp in Fortran).

It is set in cs_setup.cpp, near line 1090.

Best regards,

Yvan
by Yvan Fournier
Tue Apr 07, 2026 9:42 pm
Forum: code_saturne usage
Topic: How to properly use LTS
Replies: 5
Views: 4759

Re: How to properly use LTS

Hello,

1) I did not check the exact formulas used (the code is in cs_time_step_compute.cpp, but also has additional layers in cs_matrix_time_step calls), but by default, there is indeed both a Courant and Fourier limitation. In the solid zone, the CFL should be zero, so only the Fourier part is ...
by Yvan Fournier
Sat Mar 21, 2026 12:14 pm
Forum: Syrthes related questions
Topic: process oiur faire remonter un bug dans Syrthes?
Replies: 3
Views: 6567

Re: process oiur faire remonter un bug dans Syrthes?

Hello,

Ok thanks, this will be in the next update of Syrthes (probably in a few weeks).

Best regards,

Yvan
by Yvan Fournier
Mon Mar 16, 2026 4:01 pm
Forum: Syrthes related questions
Topic: process oiur faire remonter un bug dans Syrthes?
Replies: 3
Views: 6567

Re: process oiur faire remonter un bug dans Syrthes?

Hello,

There is currently no external GitHub of Gitlab mirror for Syrthes, and the support address may not be checked as regularly as that for code_saturne (development resources on Syrthes are currently quite limited, but some members of the code_saturne dev team have write access to the internal ...
by Yvan Fournier
Tue Mar 03, 2026 7:17 pm
Forum: code_saturne usage
Topic: Recommandation for polyhedral cells
Replies: 2
Views: 7135

Re: Recommandation for polyhedral cells

Hello,

For polyhedral meshes, our feedback is still limited, but your options seem reasonable.

Independently of the mesh type, small time steps usually lead to faster linear solver convergence, so for such cases, gradients and balances (whose cost is independent of the time step) can become ...
by Yvan Fournier
Tue Mar 03, 2026 6:05 pm
Forum: Installation issues
Topic: [SATURNE-9.1.0] Compilation with MEDCoupling 9.15.0
Replies: 1
Views: 7513

Re: [SATURNE-9.1.0] Compilation with MEDCoupling 9.15.0

Hello,

The lines in the "configure" are just initializations before the test.

We have had issues with MEDCoupling link on one machine running RHEL 8.8 after a system upgrade due to C++ API achanges, but recompiling both MEDCoupling and code_saturne avoids the problem. An alternative was to add the ...
by Yvan Fournier
Thu Feb 19, 2026 6:22 pm
Forum: Syrthes related questions
Topic: CS/Syrthes Coupling
Replies: 5
Views: 14746

Re: CS/Syrthes Coupling

Hello,

1) We assume that for a pseudo-steady computation, h and temperatures will all stabilize, so the flux expressed as "h(Tw-Tf)" should stabilize. Ideally, in a linear wll law region in a mesh convergence study, the flux should reach a fixed value (assuming wall law computation is also ideal ...