code_saturne User's Forum

Update: I managed to prevent the program from aborting when setting time_order=2 by editing the varpos.f90 file. By activating time_order=2, everything implemented for second-order time discretization executes accordingly. Analyzing cs_turbulence_kw.c, I noticed there's no code to run in second ord...

Yvan,

Yes, with the code I showed, the simulation runs despite the warnings.
This is interesting because using second-order in time allows for larger time steps (under a certain accuracy criterion), thereby reducing the need for extensive cluster resources over time.

Thank you, Yvan. I am open to contributing in any way I can, considering this is something that applies not only to my particular case.

Hi everyone, I would like to use, where possible, a second-order temporal discretization for all relevant equations in an incompressible case with the DDES k-omega SST turbulence model. I understand that, in the case of this model, there is a restriction against using second-order time discretizatio...

Hello, I am not sure about this. I checked the code today, and I seeat least some schemes require defining a min/max value which is easy to define for scalarsbet less so for vectors (I.e. do we limit the norm or the components, or a combination thereof ?). And as far as I know, the other options al...

Thank you, Yvan. I'd like to ask: if I use ischcv=1 and isstpc=3, would I be emulating the TVD Bounded CD scheme? (Using CD whenever boundedness is ensured, and otherwise resorting to upwind 1st order). In essence, my goal, rather than being able to use ischcv=4, is to use a high-order scheme that e...

Hello Yvan, thank you for the response. I tried setting isstpc to 0, 1, and 2 (i.e., all possible values) for velocity, but in all cases, I get the same error message: "invalid value of ischcv". I'm interested in using it for velocity, but now I see that if I try the same for the omega var...

Hello everyone. I'm trying to use TVD (Total Variation Diminishing) schemes as advective schemes by setting them in cs_user_parameters.c. However, I always encounter this error message as soon as the run starts. ../../../code_saturne/src/alge/cs_convection_diffusion.c:4786: Fatal error. invalid valu...

Thanks Martin,

Now I can clearly see then that by adding the implicit term, a term with is introduced which cancels out the explicit term.
Thanks for the explanation.

Hi all, I'm thoroughly analyzing the implementation of hybrid turbulence models, specifically regarding RANS and the k-omega SST model. I'm working with version 8.1. While examining the code in cs_turbulence_kw.c , I've come across something that doesn't quite add up regarding the explicit/implicit ...