Search found 4301 matches

by Yvan Fournier
Thu Jun 04, 2026 11:16 pm
Forum: Discussion
Topic: Poor cylinder wake results on unstructured meshes in Code_Saturne 9.1
Replies: 1
Views: 3444

Re: Poor cylinder wake results on unstructured meshes in Code_Saturne 9.1

Hello,

Note that v9.1 is not a fully validated version, so may have some bugs.

In any case, the first thing to try is to add at least 1 layer of extruded cells at the outlet (you can do this directly in code_saturne, see the preprocessing section of the GUI).

For outlet conditions, trying both ...
by Yvan Fournier
Wed Jun 03, 2026 6:05 pm
Forum: code_saturne usage
Topic: A small printing bug in setup.log for the VOF interface compression parameters
Replies: 1
Views: 3146

Re: A small printing bug in setup.log for the VOF interface compression parameters

Hello,

Thanks for the feedback. This is now fixed in the master branch, an I'll fix it in v9.0 also if it appears there also.

Best regards,

Yvan
by Yvan Fournier
Wed May 13, 2026 9:50 pm
Forum: code_saturne usage
Topic: Non-physical pressure difference in an annular porous media zone (Pipe Flow)
Replies: 4
Views: 6614

Re: Non-physical pressure difference in an annular porous media zone (Pipe Flow)

Hello,

Does the high pressure region appear along the whole axis of the pipe or closer to the inlet or outlet ? This might be due to a combination of inlet or outlet boundary conditions and gravity.

Can you try using a regular outlet instead of an imposed pressure outlet ? When using an imposed ...
by Yvan Fournier
Tue May 12, 2026 6:28 pm
Forum: code_saturne usage
Topic: Non-physical pressure difference in an annular porous media zone (Pipe Flow)
Replies: 4
Views: 6614

Re: Non-physical pressure difference in an annular porous media zone (Pipe Flow)

Hello,

Coule you provide more information (pas per the forum usage recommendations) ?
Without any info on the code version, model used, type of mesh, setup, ... it is difficult to provide a relevant answer.

Best regards,

Yvan
by Yvan Fournier
Mon Apr 27, 2026 2:50 pm
Forum: code_saturne usage
Topic: Poisson equation solution using Code_Saturne solver
Replies: 2
Views: 8146

Re: Poisson equation solution using Code_Saturne solver

Hello,

Boundary conditions in code_saturne may use coupled components for multi-dimensional fields, which is not the case for neptune_cfd. For scalars, coefficients should be similar.

I am out of office today (without my work computer) so cannot check the neptune_cfd code right away (and the rest ...
by Yvan Fournier
Mon Apr 27, 2026 2:33 pm
Forum: code_saturne usage
Topic: How to properly use LTS
Replies: 8
Views: 16988

Re: How to properly use LTS

Hello,

Thanks for the feedback for the linear solver tolerance. This is a tricky subject, because the tolerance used is strongly related to the right-hand side normalization choice, and this has changed several tiles across code_saturne versions to try to have the "best" possible logic (i.e. be ...
by Yvan Fournier
Thu Apr 16, 2026 5:53 pm
Forum: code_saturne usage
Topic: How to properly use LTS
Replies: 8
Views: 16988

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: 8
Views: 16988

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: 12651

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: 9253

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