[gu1]

Hi,

I need to write a eddy viscosity equation (nut) for my kOmega model. The equation is attached.

I would like help to be able to write the ReTau function because I am not able to create a this function (...and the biggest problem is to write the uTau equation).

// I need to write an equation for ReTau

tmp<volScalarField> Foam::kOmega::fMu() const
{
return (scalar(1) - exp(-y_/15);
}

tmp<volScalarField> Foam::kOmega::fDR() const
{
return return (scalar(1) - exp(-ReTau/6.25));
}

void Foam::kOmega::correctNut(const volScalarField& fMu , const volScalarField& fDR)
{
nut_ = fDR*Cmu_*fMu*k_/omega_;
}

I tried this code below, but it gives error when compiling ...

tmp<volScalarField> Foam::kOmega::fDR() const
{
const label patchi = patch().index();

forAll(mesh.faces(), faceI) //wallFaces?
{
label celli = patch().faceCells()[facei];
tmp<volScalarField> uTau = pow025(Cmu_)*sqrt(k[celli]);
}

tmp<volScalarField> ReTau(uTau*y_/nu_);
return return (scalar(1) - exp(-ReTau/6.25));
}

Error:

: error: ‘patch’ was not declared in this scope
const label patchi = patch().index();

: error: ‘facei’ was not declared in this scope
label celli = patch().faceCells()[facei];

: warning: unused variable ‘patchi’ [-Wunused-variable]
const label patchi = patch().index();

Thanks

[gu1]

Can someone help me?

[gu1]

Can someone help me? 2

[raumpolizei]

Hey there,
taking a look at your code and the error, it is quite clear what is not going well.

Originally Posted by gu1

: error: ‘patch’ was not declared in this scope
const label patchi = patch().index();

: error: ‘facei’ was not declared in this scope
label celli = patch().faceCells()[facei];

: warning: unused variable ‘patchi’ [-Wunused-variable]
const label patchi = patch().index();

in this context, the compiler can't know what you mean with patch().index(). patch() is a member function of the class fvPatchField (here, it is helpful to take a look at the documentation - www.openfoam.com/documentation/cpp-guide/html/)
Also, you define faceI in your forAll macro but then you use facei inside of the loop.
The last warning is not causing your code to not compile. However it tells you that you are defining something that you are not using.

tmp<volScalarField> uTau = pow025(Cmu_)*sqrt(k[celli]);

In the best case, this will not compile. The worst would be that it does. This will create for each loop iteration a field with the same value (based on the last value of celli, which is btw also not defined in the part you've shown).

I think you should take a look at a few more turbulence model classes as starting point. Read the OF programmers guide (google). Find the one class that suits best to your problem (if it's kOmega, great) and then implement the few functions needed in that framework. Write how it should be working on paper and then find functions that mimic the expected behaviour (and adapt them). What you seem to be doing is wild copy-pasting and it will probably not lead you to your goal.

wish you good luck!
RP

[gu1]

Originally Posted by raumpolizei

Hey there, taking a look at your code and the error, it is quite clear what is not going well.

Yes, I am aware that it is not right ... my intention was actually to show what my goal was. I believe it is not easy to implement a uTau function inside a kEpsilon.C file and alone I believe I can not do it. My intention with the post is to call on the help of more experienced people...