code_saturne User's Forum

Thanks Yvan for the quick reply as always !

The problem with cdtvar with a steady computations (LTS) is that the solution is dependent to the value of cdtvar.

If the recommendations (given above) are to run LTS simulations with CFL average <~ 1, cdtvar >1 artificially increases the CFL number for ...

Dear Yvan,

Thanks for your answer. I confirm that if the time step is lower because of a the lack of a lower limit of the time step it increases the diagonal dominance.

We have observed a tricky behavior of the code :
- In some situation, when you decrease the minimal time step factor to reach a ...

Hello,

Thanks you for the clear answer.

1) thanks for the tips. Regarding the solid region in Paraview we always have a Fourier of 0. Should I understand that the Fourier number is not involved in the calculation of the time step in solid regions ? In that case how it's determined ?

2) Yes we are ...

Dear Yvan,

Thanks for your very useful feedback. We compare the evolution of temperature probes and note an important time dependency (time average) depending on LTS settings. We are still investigating the gap between solutions. Currently, this seems to be related to the choice of the time step ...

Dear Forum,

We are facing issues with the local time stepping for buoyancy driven flow (and conjugate heat transfer). From our understanding the local time step would be calculated as follow :

- dtCFL = max( min(CFL*dX/U, tref * fmax) , tref * fmin)
- for the solid an analogous relation based on ...

Dear Yvan,

Thanks for the detailed feedback regarding gradient limiters.

We are currently performing the simulation in steady state (local time stepping approach with default settings). I forgot to mention that the mesh size is 3.5 M cells, we are using 32 cores and code_saturne 9.0.

The ...

In case of a polyhedral mesh generated by fluent mesher what are the recommendations in term of schemes and linear solver (highly turbulent flow, variable density and CHT) ?
The mesh non-orthogonality is less than 70°.

Currently I use SOLU for convection terms and leastSquares for gradients ...

Thank Yvan,
it's working !
PF

Dear Yvan,

I have reinstalled everything (OS and code_saturne 6.0.4) and now it works (ubuntu 18.04, 16.04 and also Debian 10). The messages are well printed in the listing file. I probably did something wrong during the installation stage.

Nevertheless there is another problem with the routine ...

Dear Yvan,

I confirm you that adding the zone as head losses in the gui doesn't solve the problem.

Following your recommendations I have tried with another user routine. Unfortunately I see no print with the cs_user_parameters-base.c routine when adding bft_printf("here") inside each void function ...