restart - remove user scalar

[FannyD]

Hi,

I’m running a coupled simulation of gas mixture with thermal effects (H2 in air).

As the mass flow injection of the second gas is really low, once I’ve reached the thermal convergence, I’d like to accelerate the calculation by solving only the transport of the user scalar representing H2 (with frozen velocity/pressure fields, and while removing Syrthes instance).

Currently, I’m running the restart simulation with the same number of scalars as the initial simulation, and I put all unused scalars to 0 (with null Neumann condition at all BCs). Thus, my user scalar has good restart values, but Code_Saturne has to calculate all scalars transport, which slows the calculation.

I’d like to remove all unused user scalars, but just removing them don’t work. The matter is, I can’t find where I can modify iscold(isca(n)) for the restart, and without modifying it, my user scalar takes the values of temperature at the previous calculation.

ps : I’m using version 3.0.7.
Thank in advance

Fanny

[Yvan Fournier]

Hello,

In version 3.0, the indicated place to set iscold would be in cs_user_parameters.f90, in the "usipsu" subroutine. This should work fine (though this feature is rarely used, it is maintained).

Regards,

Yvan

[FannyD]

Hello,

OK I'll try this. Thanks a lot for the help.

Regards,
Fanny