code_saturne User's Forum

Hello,

1- Sometimes when i stop a steady simulation (SIMPLE algorithme), i can not run another calculation by using the restart file with the same parametres that i was using for the first calculation and the simulation diverges. So i should re-start the from zero. This is not the case by using SIMPLEC algorithme.

2- Another question is about the convergence criteria. in C-S, Is the solver precision represent the convergence criteria? Otherwise how can i fix a convergence criteria to stop calculations?

Thanks

Hello,

1) Which version of the code are you using ? Do you have small test case which reproduces the issue ?

2) There is currently not automatic global convergence test. To check for convergence, the best is probably to follow the recommendations on this site's BPG guidelines: http://code-saturne.org/cms/sites/defau ... meters.pdf

Regards,

Yvan

Thanks Yvan
My case study is an incompressible jet with DeltaP=8 bars. I attached the contour of velocity. Restarting the calculation by these values, the simulation diverged. SIMPLE algorithme with k-e standard. I tried to change the relaxation factors but it did not work.

Wold you please explain what it means to me derive in log file in information on convergence? Is the the normalized drive between first and last itteration or between two consecutive itterations?

Hello,

derive has a different meaning depending on the version of the code you are using, so I can't explain without this info (if I am correct, in older versions it was relative to one "sweep", in newer versions, it is relative to the whole iteration). In any case, I am pretty sure it is between 2 iterations (or sweeps), and not relative to the starting iteration.

Regards,

Yvan

Tnx Yvan

Do you know how can i find some information concerning pseudo time stepping used in the SIMPLEC algorithme and SIMPLE algorthme as wel? Actually in the theory guide this part is in progress!

Hi,

You can find some information in the theory guide in "navsto" "preduv" and "resolp" parts (in french).