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Laminar-turbulent transition model in OpenFOAM

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Old   February 16, 2011, 13:23
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I am not familiar with OpenFOAM so I can only tell you how to fix the transition point numerically. Assuming that you know the region where the flow is laminar, you should define this region in term of x, y, z before executing the simulation. You will then need to modify your flow solver in such a way that the turbulent viscosity is set to zero in every cell within the predefined region. Downstream of this region, the turbulence model will force the flow to become turbulent and the transition point is approximately at the interface. Of course this only works if you already know the transition point.
how can i apply you suggestions???
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Old   February 16, 2011, 13:37
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You have to implement it into your flow solver which is OpenFOAM in this topic. This should be easier than implementing a transition model.
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Old   February 16, 2011, 13:49
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hi tue, thank you for you quick answer and sorry for my english!
ok, i use openfoam.
i know that i can modify the solvers of the tutorials, and compile them. i want to use simplefoam.
now my question is: which file (for example a header file) may i modify to impose that before the point of transition, the nut is zero, and after this point the value of nut is different for zero??
thank very much
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Old   February 16, 2011, 14:17
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As I said before, I am not familiar with OpenFOAM so I cannot tell you where exactly you can make that modification. One way to do it is as follows: you should have a routine that compute an intermittent variable. This variable should be 0 in the laminar region that you prescribe and 1 elsewhere. Then you should look for the routine where the production of turbulence kinetic energy is computed (this production term is a source term so look for source terms). You can then simply multiply the intermittent variable to the production term. This means that there is no production of turbulence in the laminar region and thus the turbulent viscosity is null.

Implementing a transition model is an extension of the above procedure. You typically will need to implement transport equation(s) for the intermittent variable based on physical arguments and empiricism.
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Old   May 30, 2011, 02:57
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Quote:
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Krause M, Ballmann J (2008) Application of a correlation-based intermittency transition model for hypersonic flows. DGLR Kongress 2008 Darmstadt 23-25 Sept 2008.
Alternatively you can send me an email and I will send you the paper.

Tue

Hi everybody.
How can I have the paper ?Do you have it? Can you please send it to me.

Mohammad.moshfeghi@gmail.com

I will be really grateful.
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