[panda60]

Dear Foamers,
I am a beginer of LES, I want to use the standard smagorinsky model.
In OpenFOAM, has smagorinsky and smagorinsky2 model.
what's the differences between them ? want is the 3-D filter ?

In OpenFOAM tutorials directory, only has one case using oneEaEddt, so it can't be used to modify.
If use smagorinsky model , them how many variables should be set for initial and boundary condition in 0 directory ?

Thank you very much.

Hey Panda,
Did you ever get an answer to that question? Do you know how to run Smagorinsky2? Somehow it doesn't run with pisoFoam...
Regards
Stefanie

[maysmech]

Hi,
I have this question too. Any idea?

[maysmech]

Another question:
As you know Cs can be 0.1~0.2. I think default value is 0.2 for smagorinsky. Isn't it?
I want set it 0.1 to decrease diffusion in my simulation. What should be done to do that?

Regards,
Maysam

[adambarfi]

hi everybody,

somewhere I read that Smagorinsky2 is the Smagorinsky model with 3-D filter, is it true?
in other word can I use Smagorinsky for 3D flows or I must use Smagorinsky2 instead?

can anyone explain the difference between these two models?

thanks in advance,
Mostafa

[cnsidero]

The source code is your friend. Verbatim from their respective header files:

from $FOAM_SRC/turbulenceModels/incompressible/LES/Smagorinsky/Smagorinsky.H

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

where

D = symm(grad(U));
k = (2*ck/ce)*delta^2*||D||^2
nuSgs = ck*sqrt(k)*delta
nuEff = nuSgs + nu

from $FOAM_SRC/turbulenceModels/incompressible/LES/Smagorinsky2/Smagorinsky2.H

B = 2/3*k*I - 2*nuSgs*dev(D) - 2*cD2*delta*(D.dev(D));
Beff = 2/3*k*I - 2*nuEff*dev(D) - 2*cD2*delta*(D.dev(D));

where

D = symm(grad(U));
k = cI*delta^2*||D||^2
nuSgs = ck*sqrt(k)*delta
nuEff = nuSgs + nu