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Shuo June 25, 2007 02:27

LES questions
 
Do all LES use finite volume methods?

Dave June 25, 2007 05:56

Re: LES questions
 
No

Shuo June 25, 2007 05:58

Re: LES questions
 
WHat are the advantages of using finite volume over finite difference for LES?


phil June 25, 2007 13:17

Re: LES questions
 
- Finite difference can use more accurate schemes (for spatial discretization). For LES this advantage is very important for academics research. If you can reduce significantly numerical error cause by discretization , you can most understand the effect of LES model.

-Finite volume can shape more sophisticated body. It's a very important advantage in the case of industrial research.

In the two case, you can use LES. But like everything, there are 'no magic solution'. In the two cases, you pay a price in order to have something.

Shuo June 25, 2007 20:48

Re: LES questions
 
How long would it take to convert a RANS solver to a basic LES solver?


phil June 26, 2007 02:12

Re: LES questions
 
I don't know.

Praveen. C June 27, 2007 09:02

Re: LES questions
 
The difference is really between structured and unstructured grids. You can have very accurate finite volume schemes on structured grids but the same is not possible with unstructured grids.

jojo June 27, 2007 10:15

Re: LES questions
 
You can, indeed, but at a very high cost. Furthermore, a high order shape function to reconstruct the fluxes and a high order surface integration impact the structure of the matrix and thus the robustness of the numerical method.

phil June 27, 2007 10:34

Re: LES questions
 
You can't have the same accurate with finite volume. For example, you can't try a finite volume with the same accurate and cost than high order ompact schemes. And when you want to study some LES model or very special turbulence cases, finite volume is not the right way !

But you're right, -the- difference is really between structured and unstructured grids. But, really can you can explain that is the difference between finite volume and finite element in the case ?


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