Search found 44 matches

by Martin FERRAND
Thu Dec 08, 2022 10:31 pm
Forum: code_saturne usage
Topic: z_ground divergence atmo module
Replies: 7
Views: 18133

Re: z_ground divergence atmo module

Thank you for your answer. I have no time to check the resu tonight but I can try to answer some of your questions : - z ground is used to imposed initial and boundary profile for the velocity and the (potential) temperature with relief. In Monin Obukhov profiles we take the distance to the ground i...
by Martin FERRAND
Wed Dec 07, 2022 7:42 pm
Forum: code_saturne usage
Topic: z_ground divergence atmo module
Replies: 7
Views: 18133

Re: z_ground divergence atmo module

Dear SimBu,
I suspect there is something wrong in you user subroutines because a ground has already been computed (from 0 to 50m) and should not be computed again.

Do you have any user subroutines which would explain the problem?
Best regards
Martin
by Martin FERRAND
Thu Sep 23, 2021 8:05 pm
Forum: code_saturne usage
Topic: Friction heating in heat transfer
Replies: 9
Views: 3270

Re: Friction heating in heat transfer

Hello, Just to answer to your first question: in the incompressible module the friction source term is neglected and not in the code. You can add it as a user source terme. For the compressible module, the solved equation is the total energy and the terme is handelled. Concerning the wall function, ...
by Martin FERRAND
Wed May 19, 2021 9:02 pm
Forum: code_saturne usage
Topic: [Dispersion in frozen flow] - issue with user scalar value at boundary
Replies: 5
Views: 2321

Re: [Dispersion in frozen flow] - issue with user scalar value at boundary

Hello,

I think you should impose a flux rather a Dirichlet BC because otherwise the ongoing value of scalar is only from diffusion flux.

Could test that?
There is also a possibility to perform scalar balance in the GUI.

Best Regards
Martin
by Martin FERRAND
Mon Jan 11, 2021 9:19 am
Forum: Discussion
Topic: Documentation of rough wall boundary conditions
Replies: 5
Views: 13750

Re: Documentation of rough wall boundary conditions

Hello, Indeed eq I.5.25 has a typo (no Clog). I will correct that. Concerning the two velocity scale, yes there are other references you can read (Craft, and also PHD of Jean-Francois Wald). The derivation of the BCs of k and epsilon is detailed in appendix (which help reading the code). Indeed the ...
by Martin FERRAND
Thu Jan 07, 2021 7:39 pm
Forum: code_saturne usage
Topic: [Saturne 6.0.6] Particles are accelerated by head loss
Replies: 12
Views: 5441

Re: [Saturne 6.0.6] Particles are accelerated by head loss

Dear user, Thank you for the feedback. We are aware of this problem which is due to the fact, if I understand well, that the additional force you have on the mean fluid (with the head loss) is missing in the lagrangian module (all terms on the momentum are not automatically taken as they should). We...
by Martin FERRAND
Wed Jul 22, 2020 5:24 pm
Forum: code_saturne usage
Topic: ALE - mesh viscosity in v6.0
Replies: 12
Views: 7976

Re: ALE - mesh viscosity in v6.0

Dear Daniele, The CDO solver used for ALE is not compatible yet with FSI (and INTERNAL coupling) because the way boundary conditions are treated are really different (using the GUI it is transparent, but you cannot use cs_user_boundary_conditions_ale.f90 for the CDO solver). We check if it is possib...
by Martin FERRAND
Thu May 30, 2019 3:56 pm
Forum: code_saturne usage
Topic: Boussinesq approximation
Replies: 6
Views: 4742

Re: Boussinesq approximation

Hello, since version 6.0 there is an option to activate the Boussinesq approximation (indeed rho varies only in the buoyancy term and is supposed to be constant everywhere else).
Look for idilat = 0 in cs_user_parameter file.

Best Regards
Martin
by Martin FERRAND
Thu May 30, 2019 1:42 pm
Forum: code_saturne usage
Topic: total pressure and gravity
Replies: 5
Views: 3619

Re: total pressure and gravity

Hello, If you want to model a free surface, you can also test the ALE module and then “free surface” boundary condition will be used. It will impose p0 at the freesurface and let it move with the flow. So if you have breaking waves this method does not work. We have also experimental options for tha...
by Martin FERRAND
Thu May 30, 2019 1:38 pm
Forum: code_saturne usage
Topic: VOF and ALE compatible?
Replies: 3
Views: 3234

Re: VOF and ALE compatible?

Hello, It should be compatible but we don’t have any validation test case for that so that would be nice if you could set up a toy model test case to check if it is working correctly. If not, that will not be a big deal to fix (ALE is mainly impacting the other fields updating convective mass flux, ...