[agustinvo]

Hi everyone,

I am studying the heat transfer in a channel flow, where I have to use a turbulence model to close the Reynolds stresses (in my case, the Wilcox k-Omega model) and other one to model the turbulent heat transfer. I am using a modified SimpleFoam as a solver.

Following the paper I have, it is said to apply at first place the k-Omega model, and after that the heat transfer model. This implies that I have to use two turbulence models, and I only can write one in the RASProperties file.

I have different options:

• Run two simulations (one for each model), modifying RASProperties tochange the turbulence model
• Modify the solver, to solve at the begining the momentum equation, and continue with the energy equation, so I have to run two loops of iterations
• Modify how OpenFOAM reads the RASProperties file, giving one of these models,

Since I have no administrator access, and I will use this approach in a cluster, which option do you think is more easy to implement? Maybe the thing I need is just a few Linux commands. Could it be a way to use a second RASProperties file?

Thank you in advance!

[KingKraut]

Hi augustinvo,

although a couple of years ago, maybe you remember this thread? :-)
i hope you are well!
did you find a solution for your problem?

i am in a similar position right now. I would like to apply different parameters in the turbulence model at different regions within the model, however during the whole simulation.

would be glad, if you could let me know, if you managed to solve your problem. maybe this could give me a hint, as well.

thanks a lot in advance.

best wishes
Johannes

[agustinvo]

Hi KingKraut,


I solved my problem some time ago, but I think your scope and mine are a bit different.


If you want to use the same turbulence model everywhere but using different coefficients, you could modify your turbulence model in such a way that you read your coefficients as volScalarFields, that you have to set to your desired values using, for example, setFields, funkySetFields...


I hope it can help you.

[KingKraut]

Hi augustinvo,

thanks a lot for your answer.

you are right, the situations are somewhat different :-)

In the meantime i also realized there are a couple of solvers that allow the use of different regions. If I saw it correctly, in these regions different turbulenceModels and hence different parameters as well, can be applied.
Did not have the time to look into it, yet. But if it doesnt work, I will certainly give a custom turbulenceModel as you suggested a go.

Thanks again!
Cheers

[GerhardHolzinger]

If for some reason, the approach using multiple regions does not work, you could have a look into the fluid-fluid tutorial case from the precice website..