Questions Regarding Real Gas Effects in PeleC

[Alex-jian522]

Hello everyone,
I have two questions regarding the inclusion of real gas effects in PeleC.
In my setup, I have the following configuration in CMakeLists.txt and GNUmakefile:

Based on the documentation here: EOS documentation and Transport documentation, I believe this setup accounts for the real gas effects on thermodynamic properties (including internal energy and enthalpy), as well as viscosity and thermal conductivity. Is this correct?

Regarding real gas effects, the mass diffusivity of species is typically modeled using Takahashi’s high-pressure correction. However, I could not find any mention of this correction in PeleC. How is the species mass diffusivity ( D_i ) calculated when using the SRK EOS? When using SRK EOS, how do I use the constant Lewis number or even the unity Lewis number model?

Thank you very much for your help!

[drummerdoc]

The modifications employed with the SRK EOS are summarized in the PelePhysics documentation (and also include changes to the chemical kinetics expressions, by the way). See https://amrex-combustion.github.io/PelePhysics/EOS.html. Reach out if you need more info.

[Alex-jian522]

Thank you very much. I have read the above documents carefully and the content is very detailed, but there is no explanation on the species mass diffusivity ( D_i ) calculated when using the SRK EOS?

[baperry2]

We do modify transport coefficient calculations for real gas effects with the SRK EOS. You can see the modified calculation in the source code here: https://github.com/AMReX-Combustion/PelePhysics/blob/0257b2366ecf421ae554c8e2457776d4823f4bfb/Source/Transport/Simple.H#L182

Then we use Chung's corrections for thermal diffusion and viscosity.

[Alex-jian522]

Thanks a lot! I think I understand now!

[drummerdoc]

@baperry2 Sounds like we need to add a small section to the documentation.

[Alex-jian522]

I have one more question regarding the SRK EOS. When using SRK EOS, can I use the constant Lewis number or even the unity Lewis number model?

[baperry2]

Unity Lewis number transport is not supported in PeleC. Probably wouldn't be too hard to set up using the ProblemSpecificFunctions::problem_modify_transport_coeffs functionality though. See the EB_ConvergingNozzle case for an example.

[Alex-jian522]

Thanks, so what about the kinetics law? Does PeleC make a modification to consider the mass action law like the following paper? (Real gas effect on steady planar detonation and uncertainty quantification, Zifeng Weng, Rémy Mével, CNF, 2022)