Hi, I modified the built-in
I modified the built-in kEpsilon model of OpenFoam according to a paper. unfortunately the results are not at all what we expected.
I used the standard kEpsilon Model and turbFoam to produce vortex shedding behind a square cylinder (Re = 20000) and then wanted to restart with my modified model.
The paper states (results with an proprietary code) that the effect should be almost instantly - considering I practically change C1_ in the code that makes sense to me.
But nothing happens the drag and lift coefficients are (periodic) exactly the same as before.
I tried a lot and I can rule out a wrong formula - what I can't rule out is the accidental misuse of variables while coding - therefore I hope you can take a look at my modification and check if I do something what should not be done.
Here is the important extract of my modified file:
volScalarField G = nut_*2*magSqr(symm(fvc::grad(U_)));
volVectorField dU = fvc::ddt(U_);
volScalarField dUx = dU.component(0);
volScalarField dUy = dU.component(1);
volScalarField Gstar = 0.5*magSqr(U_)+k_;
volScalarField C1star = C1_+C1_*0.38*k_/epsilon_*1.0/(Gstar)
* mag(U_.component(vector::X)*dUx + U_.component(vector::Y)*dUy + fvc::ddt(k_));
Info << "Using modified kEpsilon model" << endl;
# include "wallFunctionsI.H"
// Dissipation equation
+ fvm::div(phi_, epsilon_)
- fvm::Sp(fvc::div(phi_), epsilon_)
- fvm::laplacian(DepsilonEff(), epsilon_)
- fvm::Sp(C2_*epsilon_/k_, epsilon_)
And here is the Link to the complete File: (I am sorry if your browser is showing a blue text between the code - just save the file to disk and it should be fine)
Hope you find something
Harly, what paper you used as
Harly, what paper you used as your reference?
Hey no problem: http://harl
Hey no problem:
I am implementing the formulation (15) in the kEpsilonMod.C.
I am using the same mesh (described in the paper) and also Re = 20000
please don't distribute the paper - thanks
Thanks - I asked you because I
Thanks - I asked you because I plan to do a similar thing. I was involved in simulating atmospheric boundary layer with modified two- equation models of turbulence (I'll send you a paper if you're interested) so I wanted to implement such "Atmospheric Boundary Layer k-e" here.
I'll take a look at your modification and see if I can help something.
Hi, I am back from the hol
I am back from the holidays and still can't find my mistake. So please if someone has an idea I am open for everything.
@Nikola: Did you have time to take a look at my code? - and yes please send me the paper of your modification.
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