Search found 126 matches

by Antech
Fri Jan 10, 2020 3:25 pm
Forum: code_saturne usage
Topic: Divergence in k-omega cases with inflation layers
Replies: 10
Views: 1681

Re: Divergence in k-omega cases with inflation layers

Yes, this is indeed the test pipe bend case with tetra mesh without layers, you can find links to download XML and mesh above (copy into the bend case from the first post) and check if you have spare time for this. I started solver successfully with "or no_group[]" added to selection criteria for th...
by Antech
Fri Jan 10, 2020 8:30 am
Forum: code_saturne usage
Topic: Divergence in k-omega cases with inflation layers
Replies: 10
Views: 1681

Re: Divergence in k-omega cases with inflation layers

Hello, Ivan. I checked the error output closer. First, in ERROR.case, there is a couple of quad faces at the outlet part created by the Mesh extrusion feature (Mesh => Preprocessing => Other => Mesh extrusion) that have BC error. I attached the picture from ParaView ( Bend-Extrusion-Error.png ), fac...
by Antech
Thu Jan 09, 2020 2:45 pm
Forum: code_saturne usage
Topic: Divergence in k-omega cases with inflation layers
Replies: 10
Views: 1681

Re: Divergence in k-omega cases with inflation layers

Ivan, I just tried to add the othogonal layer for the outlet using "Mesh extrusion" GUI feature for the OUT face group. Extrusion itself works but when the solver starts it fails because of incorrect boundary type: First face with boundary condition definition error (out of 2) has boundary condition...
by Antech
Thu Jan 09, 2020 12:50 pm
Forum: code_saturne usage
Topic: Divergence in k-omega cases with inflation layers
Replies: 10
Views: 1681

Re: Divergence in k-omega cases with inflation layers

Hello, thanks for your response. it works for k-eps without layers but does not work for k-w SST with layers Yes. But I found one strange thing with the pipe bend case . To answer your question about the mesh effect I ran the same case without layers, there was the same issue with k-omega. But, what...
by Antech
Sat Jan 04, 2020 2:10 pm
Forum: code_saturne usage
Topic: Divergence in k-omega cases with inflation layers
Replies: 10
Views: 1681

Re: Divergence in k-omega cases with inflation layers

Hello. Sorry for the late response. Behaviour is similar in versions 5 and 6, but may be different in version 4. I ran a simple test case with layers and k-omega with success in v4 but it was years ago so I don't remember if I let it to iterate enough (anyway v4 is too old). It's important not to st...
by Antech
Fri Dec 27, 2019 3:32 pm
Forum: code_saturne usage
Topic: Divergence in k-omega cases with inflation layers
Replies: 10
Views: 1681

Divergence in k-omega cases with inflation layers

Hello. Some time ago I noticed a problem with Saturne regarding any calculations with inflation mesh layers and k-omega turbulence model. First I encountered it in 5.x branch and recently I decided to check if it's still in 6.x versions so I compiled version 6.0.0 and gave it a try with 2 test cases...
by Antech
Fri Dec 27, 2019 8:42 am
Forum: code_saturne usage
Topic: System error: Too many open files in system
Replies: 7
Views: 947

Re: System error: Too many open files in system

Hello. Regarding open files. Check ulimit -a if you have problems related to the number of maximum open files. It may also be important to check (with the same command) maximum stack size and maximum amount of locked (reserved) memory (in some cases you will need unlimited for this). Persistent valu...
by Antech
Wed Apr 17, 2019 3:31 pm
Forum: code_saturne usage
Topic: Wind tunnel modelling, BCs and convergence issues
Replies: 9
Views: 1296

Re: Wind tunnel modelling, BCs and convergence issues

Emonet_L Hello. In our practice (aerodynamics), we usually don't get residuals as low as 10^-4 or so. They may oscillate around 10^-3 asympote or even be higher. The other thing is that residuals may lay already oscillate around their asymptotes and be not too high while solution is not actually co...
by Antech
Mon Apr 15, 2019 7:58 am
Forum: code_saturne usage
Topic: Basic question
Replies: 1
Views: 386

Re: Basic question

Hello. Code Saturne uses SIMPLE-like, not fully-coupled solver. For this type of solvers, solution stability often becomes a problem (regardless the particular program you use). If you work with gas and only need static results, try reference time step 0.0001 s, and max timestep multiplier 100. If y...
by Antech
Thu Apr 04, 2019 4:55 pm
Forum: code_saturne usage
Topic: Best practice restarting case
Replies: 2
Views: 607

Re: Best practice restarting case

Hello. When you choose to restart the calculation, Saturne immediately asks you for the results directory. In the window appeared choose the checkpoint directory of the previous run. Then it should restart normally. Please note that Saturne 5.x only supports simple restarts with the same mesh (witho...