CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   LES delta (http://www.cfd-online.com/Forums/main/8749-les-delta.html)

turb February 25, 2005 22:34

LES delta
 
Hi all, In a mesh highly anisotropic and unstructured, what is the best way to calculate delta to be used in LES sgs models (say, Smagorinsky and oneEquation models, for instance)? Obviously, in this case the classic volume cubic root would not work, and the other options I know need a cartesian mesh...

Thanks in advance, sampaio

noName March 1, 2005 20:30

Re: LES delta
 
If your grid is anisotropic and unstructured, you are dealing with a filter that varies in space.

In any calculations, simply make \Delta a function of space..

turb March 2, 2005 15:27

Re: LES delta
 
Is it really only that? Cause my delta is already a function of x,y,z (I am using cubic root of cv)

I wonder what happens if deltaZ is not in inertial range any more... This will certainly happens, if you deal with separated flows (wake behind a cylinder, for instance) and cannot afford the burden of building different dz in the spanwise direction acording to your physics (gradative braking down of vortex, evolving towards turbulence further downstream...)

Thanks for your comments.


All times are GMT -4. The time now is 20:10.