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Jonathan Lemay February 29, 2008 13:36

LES models:
Dear CFD users

I am performing a LES simulations on a cold flow of a Bluff-body burner. When I look at the Transient Statistics available in the Output Control tab, there is something called LES Dynamic Model Coefficient.

I though that the only model for LES and Subgridscale available in CFX was the Smagorinski model... When I look on what I found in the Output Control it seems that their is another model available. If it not the case what this LES Dynamic Model Coefficient mean???

I am looking to use the Germano dynamic approach, as it let the C constant be dynamic for each time step.

Thanks in advance

opaque February 29, 2008 14:07

Re: LES models:
Dear Jonathan,

What version of ANSYS CFX are you using? I just look in ANSYS 11.0, and there are 3 LES models: Smagorinsky, WALE and Dynamic.

Setup the case as transient, and under Domain/Fluid Models/Turbulence Model check in the ... section.


Jonathan Lemay February 29, 2008 15:50

Re: LES models:
Dear Opaque

Thanks for your tips. You are right... I have been in another computer in which Ansys 11.0 is installed. I found the Dynamic model. My problem is that on the cluster of my school the WALE and Dynamic option do not appear.

Is there a way to make them appearing. Should we get a special license for that?


alpha February 29, 2008 18:13

Re: LES models:
Have you enabled beta fatures of CFX. If you do they should appear where opaque mentioned.


Jonathan Lemay February 29, 2008 19:10

Re: LES models:
Dear Alpha

Would you please tell me how can I do to verify if they are turned ok?


Hekler March 1, 2008 10:42

Re: LES models:
look in the options menu in pre. Beta features are enabled with a tickbox.

Jonathan Lemay March 3, 2008 07:51

Re: LES models:
Dear Hekler

Thanks for your tips. I finally find out how to enable de beta features of CFX. Great I will be able to run LES-Dynamic!! regards

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