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July 27, 2011, 09:52 |
RNG k-epsilon model implementation
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#1 |
Senior Member
Roman Thiele
Join Date: Aug 2009
Location: Eindhoven, NL
Posts: 374
Rep Power: 21 |
Hej,
I was wondering why the implementation of the RNG k-epsilon model in OpenFOAM looks so much different from the implementation of the standard k-epsilon model? Even the k-equation looks different, even though that one should be the same. k-equation standard k-eps: Code:
tmp<fvScalarMatrix> kEqn ( fvm::ddt(k_) + fvm::div(phi_, k_) - fvm::Sp(fvc::div(phi_), k_) // missing from the k-equation of RNG - fvm::laplacian(DkEff(), k_) == G - fvm::Sp(epsilon_/k_, k_) ); Code:
tmp<fvScalarMatrix> kEqn ( fvm::ddt(k_) + fvm::div(phi_, k_) - fvm::laplacian(DkEff(), k_) == G - fvm::Sp(epsilon_/k_, k_) ); eps-equation RNG Code:
// Dissipation equation tmp<fvScalarMatrix> epsEqn ( fvm::ddt(epsilon_) + fvm::div(phi_, epsilon_) - fvm::laplacian(DepsilonEff(), epsilon_) // I expect another term here == (C1_ - R)*G*epsilon_/k_ // why is the term R, which is part of the changed C_eps2 constant subtracted from C_eps1 //- fvm::SuSp(R*G/k_, epsilon_) - fvm::Sp(C2_*epsilon_/k_, epsilon_) // C2 is a constant here, even though it should be a function of the strain-rate tensor );
__________________
~roman |
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November 23, 2011, 10:19 |
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#2 | |
Senior Member
Vesselin Krastev
Join Date: Jan 2010
Location: University of Tor Vergata, Rome
Posts: 368
Rep Power: 20 |
Quote:
Best Regards V. |
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June 20, 2018, 09:33 |
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#3 | |
Member
Hosein
Join Date: Nov 2011
Location: Germany
Posts: 94
Rep Power: 15 |
Quote:
Could you find the reason why the OF version of equations are not similar to the ones of Yakhot et al. |
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Tags |
rngkepsilon, turbulence model |
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