large eddy simulation and combustion

[nedcyrille]

good evening

- Finally, i did not succeed to solve the problem of divergence with the 2nd order scheme during the simulation of the turbulent combustion using large eddy simulation.
the simulation is ok with the first order!

-I noticed that in the subroutine d3pint only three species are calculated; if i need to calculate 4 species for example (ch4, o2, h2o, co2) what should I do?
I tried to modified the subroutine colecd! unfortunately!

[Yvan Fournier]

Hello,

What type of problem did you have modifying colecd ?

Regards,

Yvan

[nedcyrille]

Good morning i'm simulating a turbulent flame. The species are ch4, o2, co2 and h2o. What i notice is that inside the subroutine d3pint, 3 species are imposed, while i would l'île to have 4. I dont know how to solve that problem.

[Yvan Fournier]

Hello,

You can probably build a 3-species model using a "d4pint.f90" based on and adapted from d3pint.f90, but this may lead to modifying many other things. I do not know the combustion models in the code very well, so I do not know whether this amount to developing a new combustion model (possible) or is simpler, but this is a path that might require significant additions. I can try to check with people using gas combustion if they have recommendations.

Best regards,

Yvan

[nedcyrille]

Good evening!
This is the error i had when i tried to modifie colecd

[Mabley]

Hello all,

Does anyone here succeed in coupling LES and combustion with all previous indications?
I've tried but each time I launch a simulation my setup.xml file, written by hand for the modifications, is re-written by the code.
Sometimes my combustion settings are erased or the LES_Smagorinky turbulence model is changed in k-eps-LP one.
And when nothing is modified by the code, I just get an error saying there's an incompatibility between LES and combustion.

So help is very welcome in any form.
Best regards,
Mabley

[Yvan Fournier]

Hello,

As the GUI tries to select only "compatible" options, it might reset your turbulence model to RANS if you activate combustion after choosing LES, or remove the combustion model if you force LES.

The best solution here is probably to set the combustion model in the GUI, and force the turbulence model in cs_user_parameters.

Regarding the incompatibility, you will need to modify src/base/verini.f90 to remove the matching check.

I am not sure this is sufficient though, as there might be turbulence-related combustion source terms, which will need to be adapted, so you need to proceed by steps (and since several people have the same type of questions, I'll be happy to follow and help where I can if you can progress as a group and help each other out).

I will try to remember to check with people working on gas combustion whether they have tried or are planning to extend the models to LES.

Best regards,

Yvan

[Mabley]

Hello Yvan,

Thank you very much, it is working now. It was an easy change to do.
I don't look after the source terms of turbulence yet, I will check it and give you feedback if I manage (or not) to do it.

Best regards,
Mabley.