Variable density issue for for gas combustion with EBU model

[CandiceLIU]

Dear Code_Saturne developers and users,
There seems to be a bug in the code regarding the activation of irovar=1 option in the main part of the code when gas phase combustion, especially the EBU model. The case setup has been done in the same manner as I have done it in Version-2 of Code_Saturne. What I have noticed is that SRROM is not reported in the listings file which was the case in version-2. Also, the density is not output in the postprocessing. I have also noticed that the velocity on the product side of the flame does not change which means that irovar=1 option is not transferred to the main part of the code and the density remains constant. To clarify, I have set-up the case in the fortran and c user subroutines and this case is to test the code. The reason for using the subroutines rather than the GUI is that I want to develop the code with different models, and this cannot be done if the GUI is used. The SRC has been attached.

To check why the relaxation coefficient was not written in V7, I found it is suspicious in the following part, the relaxation coefficient will be output on condition ippmod(iphpar).ge.2 as I highlight in the snippet 1 (/base/impini.f90). However, as you can see from snippet 2(/pprt/ppincl.f90), it can only be switched on for the specific physics plus radiative transfer problems.
I was wondering if someone else has the same issue with density not being variable despite irovar being defined (coini1.f90 & cs_user_parameter.c) while using the standard EBU model.

Best regards,
Liyuan

[Yvan Fournier]

Hello,

We should probably mode this post to the "General Usage" section.

There might be 2 separate issues here, or an interaction with the "idilat" option. With idilat = 0, you might have a Boussinesq hypothesis for buoyancy even when using variable density. Not sure if this is related.

irovar and idilat should work with any physical model. srrom is more specific to some combustion models.

I am not too familiar with those models, so if someone else has a quick answer, that would be good. Otherwise, I'll ask a colleague who knows this part better when I next see him (or contact him if I don't see him this week).

Regards,

Yvan

[CandiceLIU]

Thanks Yvan for your swift reply. I have transferred it to the code_saturne usage section.