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-   -   LES using FLUENT (http://www.cfd-online.com/Forums/fluent/33380-les-using-fluent.html)

sa April 2, 2004 18:56

LES using FLUENT
 
I am a little confused while running LES simulations using FLUENT. I am simulating Incompressible Impinging Jets. Just looking into velocity and pressure profiles and vortex generation.

1) First I run the simulation for a certain number of iterations to get statistically steady flow.

2) Then I use command solve/initialize/init-flow-statistics to zero initial statistics.

3) Then I enable Data Sampling for Time Statistics in the iterate panel.

My questions are as follows?

A)Is that the correct way to run LES in Fluent? Else please let me know if I am doing something wrong. Because in an example problem by Fluent, I saw they did not perform step 2 and went straight to step 3.

B)Also what is my criterion for selecting time step when I am running the implicit scheme? For explicit schemes, we generally resort to CFD criteria.

C)Which solver gives better results segregated or coupled ?

D) Though PISO is recommended for transient flows, it takes a lot of time. Is it ok to use SIMPLE?

E) For momentum discretization, I am using Central Diff. Is 2nd Order Upwind better?

F) Is there some tutorial using LES in FLUENT, other than the Acoustics one?

Thanks for your help.

Sincerely

sa



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