[calf.Z]

I am now trying to implant the turbulence model MK into openfoam to use it to simulate the heat transfer of supercritical CO2.
In MK model, there is yPlus in the formula of fMu:

(scalar(1) - exp(-yPlus/30))*(scalar(1)+3.45/pow(Rt,0.65));

So I am wondering how to define yPlus in this formula? Now I have some code:

volScalarField Dist(wallDist::New(this->mesh_).y());
dimensionedScalar uTau("uTau", dimVelocity, 0.025);
volScalarField yPlus(Dist*uTau/this->nu());
return (scalar(1) - exp(-yPlus/30))*(scalar(1)+3.45/pow(Rt,0.65));

I am not sure whether it should work or not. I think uTau should be calculated from wallshearstress. There are some code about tauw and yPlus in openfoam. But I can not quote them properly. Some of the code are based on wall. How can I define yPlus beyond the wall?

Any hint is highly appreciated.

[mAlletto]

You can probably use the same formula as in the nutkwallfunction:

scalar yPlus = Cmu25*y[facei]*sqrt(k[celli])/nuw[facei];

This formula is only valid for k epsiolon models and flow which are in equilibrium. but i think for attached flows it is ok.



A good explanation of various derivations of wall models can be found here:



https://www.google.com/url?sa=t&rct=...Nial_7Fsigp3V5

[calf.Z]

Originally Posted by mAlletto

You can probably use the same formula as in the nutkwallfunction:

scalar yPlus = Cmu25*y[facei]*sqrt(k[celli])/nuw[facei];

This formula is only valid for k epsiolon models and flow which are in equilibrium. but i think for attached flows it is ok.



A good explanation of various derivations of wall models can be found here:



https://www.google.com/url?sa=t&rct=...Nial_7Fsigp3V5

Thank you. I will have a try.

[mAlletto]

There is also a damping term based on ystar in the incompressible/turbulentTransportModels/RAS/LienCubicKE/LienCubicKE.C model.



This damping function is also meant to correctly reproduce the decrease of the turbulence quantities towards the wall