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by Yvan Fournier
Mon Mar 18, 2024 2:24 am
Forum: code_saturne usage
Topic: Strange Halting at Half Total Iterations
Replies: 8
Views: 74

Re: Strange Halting at Half Total Iterations

Hello, Yes, this is the default : except for test runs of 10 iterations or less, there is a checkpoint every 1/4 of the total number of iterations required. Again, do you know if there was an "upgrade"/maintenance of some librairies on your cluster ? Do you have access to other MPI librari...
by Yvan Fournier
Fri Mar 15, 2024 12:27 pm
Forum: code_saturne usage
Topic: Strange Halting at Half Total Iterations
Replies: 8
Views: 74

Re: Strange Halting at Half Total Iterations

Hello, With version 8.1, you should not have the code_saturne "race condition" bug. So this might be a problem in the system. Did you reproduce it a second time ? On our machine, we had the issue with OpenMPI 4 and 4.1 (less frequent with 4.1), but this depends on lower level elements of t...
by Yvan Fournier
Thu Mar 14, 2024 4:39 pm
Forum: code_saturne usage
Topic: Strange Halting at Half Total Iterations
Replies: 8
Views: 74

Re: Strange Halting at Half Total Iterations

Hello, I forgot to ask/you forgot to remind me which version of the code you are using. There was in issue in the restart code some time ago (more then 2 years if I remember) where we could also have a race condition leading to the behavior you observe. Otherwise, if the issue only happened once, tr...
by Yvan Fournier
Wed Mar 13, 2024 7:22 pm
Forum: code_saturne usage
Topic: Strange Halting at Half Total Iterations
Replies: 8
Views: 74

Re: Strange Halting at Half Total Iterations

Hello, What type of machine/compute environment are you running on, how many MPI ranks do you use, and how long has the code been running ? This seems to be a hang when writing an intermediate checkpoint file, and may have similarities with some issues we encountered on a cluster following a system ...
by Yvan Fournier
Tue Mar 12, 2024 11:34 am
Forum: code_saturne usage
Topic: Add source term. Need help
Replies: 1
Views: 30

Re: Add source term. Need help

Hello,

Yes, check in body forces.

Yvan
by Yvan Fournier
Mon Mar 11, 2024 2:18 pm
Forum: code_saturne usage
Topic: Scalars and RIJ ssg
Replies: 4
Views: 71

Re: Scalars and RIJ ssg

Hello,

I have suggested to some colleagues more expert in.the turbulence modeling of the code to check this post... I'll ping them again.

Best regards,

Yvan
by Yvan Fournier
Mon Mar 11, 2024 2:16 pm
Forum: code_saturne usage
Topic: Skin friction coefficient calculation
Replies: 4
Views: 82

Re: Skin friction coefficient calculation

Hello,

Yes the analysis seems correct to me. If anyone with better knowledge of this part of the code has additional details to provide, they ae welcome...

Best regards,

Yvan
by Yvan Fournier
Mon Mar 11, 2024 2:14 pm
Forum: code_saturne usage
Topic: streamwise periodicity
Replies: 26
Views: 13526

Re: streamwise periodicity

Hello, There are some user examples in.the documentation but they may not be sufficient. When.the code starts a new time step, the current value is copied into val_pre and the new value is computed. What I suspect is happening in your case is that when the source term user-defined function is called...
by Yvan Fournier
Fri Mar 08, 2024 12:51 pm
Forum: code_saturne usage
Topic: streamwise periodicity
Replies: 26
Views: 13526

Re: streamwise periodicity

Hello, Yes, you seem to be using the standard temperature resolution. Do not forget that for enthalpy, you also need to multiply by density and CP. If this is missing your sink term might simply be too small ? What are the other factors (boundary and initial conditions) influencing enthalpy here ? B...
by Yvan Fournier
Fri Mar 08, 2024 3:18 am
Forum: code_saturne usage
Topic: Skin friction coefficient calculation
Replies: 4
Views: 82

Re: Skin friction coefficient calculation

Hello, I am not sure about the skin friction coefficient. The wall stresses contain not only the pressure, but some terms related to turbulence (I am not sure about the details, but you can search for "iforbr" in src/base/predvv.f90 for versions 8.0 or older, src/base/cs_solve_navier_stoke...