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Old   August 28, 2014, 06:39
Default LES turbulence model
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Hello,
in OpenFOAM different LES turbulence models can be chosen.
For example the "oneEqEddy", which is a -equation eddy-viscosity model.
I just want to know how this model is working. Can anybody help me?
It would be also very helpful to get literature, which describes this model.
Thanks alot
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Old   August 28, 2014, 09:39
Default src/turbulenceModels/compressible/LES/oneEqEddy/oneEqEddy.H
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Well the source code gives already some clues:
Code:
src/turbulenceModels/compressible/LES/oneEqEddy/oneEqEddy.H
src/turbulenceModels/compressible/LES/oneEqEddy/oneEqEddy.C
Also check out the wiki and this thread:
http://www.cfd-online.com/Wiki/Kinet...id-scale_model
http://www.cfd-online.com/Forums/ope...-openfoam.html
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Old   August 28, 2014, 09:46
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Hello again,
thanks for your help.
I am sorry, I forget to mention I am looking at the incompressible turbulence model.

After reading the source code, my question changed a little:
In oneEqEddy.H the following equation for k is written:
Quote:
d/dt(k) + div(U*k) - div(nuEff*grad(k))
=
-B*L - ce*k^3/2/delta

and

B = 2/3*k*I - 2*nuSgs*dev(D)
Beff = 2/3*k*I - 2*nuEff*dev(D)

where

D = symm(grad(U));
nuSgs = ck*sqrt(k)*delta
nuEff = nuSgs + nu
Unfortunately I found no definition for L

If I look in the file oneEqEddy.C I found the following equation for k:
Quote:
fvm::ddt(k_)
+ fvm::div(phi(), k_)
- fvm::laplacian(DkEff(), k_)
==
G
- fvm::Sp(ce_*sqrt(k_)/delta(), k_)

with G = 2.0*nuSgs_*magSqr(symm(gradU))
As far as I understand G is a part of the term B*L.
If I am right, where is then the first part of B (2/3*k*I) in the k-equation?
Is this term necessary?

thanks a lot for your help
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