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-   -   use of Reynolds stress in CFX-post if possible? (http://www.cfd-online.com/Forums/cfx/24691-use-reynolds-stress-cfx-post-if-possible.html)

July October 19, 2007 05:12

use of Reynolds stress in CFX-post if possible?
 
Hello:

I am using CFX for turbomachinery cfd prediction.

I don't know whether it is possible to use reynolds

stress components in CFX-post without the application

of reynolds stress models?

Thanks in advance.

July

Kumar October 19, 2007 08:05

Re: use of Reynolds stress in CFX-post if possible
 
The Reynolds stress tensor (tau_ij) for an incompressible fluid in a eddy-viscosity model is defined as:

tau_ij = - u_i u_j = nu_t (partial U_j/partial X_i + partial U_i/partial X_j)

In CFX-post all derivatives of U_j or velocity vector are available. You may compute u_iu_j for the inner field without any problems. At the near-wall cell, I am not sure if eddy viscosity or nu_t values in CFX-post are correctly set.


Jonathan Lemay October 24, 2007 19:31

Re: use of Reynolds stress in CFX-post if possible
 
Dear July

Did you finally find out how to compute the Reynolds Stress with the K-E model for example. I did understand Kumar explication about the definition of the tau_ij, but when it comes time to applicate it in CFX it is different. How did you compute the turbulente viscosity?

Thanks anyone for more specification about the Reynolds tensor.

Regards


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