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August 24, 2004, 10:54 
The kepsilon model

#1 
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The linear kepsilon model assumes that the turbulence viscosity is linked to the turbulence kinetic energy and dissipation via the relation:
μt=Cμ*ρ*k^2/ε Where Cμ is a constant (ke Turbulence model constant). However, this linear model is inappropriate for swirl flows. Hence, a Cμ as a function of a shear parameter is usually defined to represent better those type of flows. Therefore, I would like to ask if is a way to define Cμ as a non constant parameter (as a function) using CFX 5.6 or 5.7 

August 25, 2004, 23:38 
Re: The kepsilon model

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You're better off using a Reynolds Stress model which solves the anisotropic Reynolds stresses in swirling flows. Hint: start with kepsilon, and then restart using the Reynolds Stress model.
Jeff 

August 26, 2004, 10:59 
Re: The kepsilon model

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Thank you Jeff, but because I have no computer power right now, I have to use the kepsilon model until I get a definite model. Any other suggestions that could help me?
Luis 

August 26, 2004, 22:12 
Re: The kepsilon model

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I haven't looked at the CCL for the turbulence models, but C_mu should be a CCL parameter (option). Look in the rules file (under the /etc directory....but don't modify this file!!!) for the kepsilon section and see if the model constants are parameters. If they are, your can edit your CCL file and set the model constant to a CEL variable. The CEL variable can then be a function of just about anything.
Jeff 

August 27, 2004, 20:42 
Re: The kepsilon model

#5 
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Thank you Jeff, I will try now


August 31, 2004, 23:48 
Re: The kepsilon model

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dear sir,
i want to know details of Kepsilon model,if u sent me the details i will thankful to you yours faithfully girish 

September 1, 2004, 11:10 
Re: The kepsilon model

#7 
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Hi Girish
You can get detail information of the model in the CFX manual under Two equation turbulence model. Also, you can read An introduction to Computational Fluid Dynamics, The Finite Volume Method by H. K. Versteeg, 1995. Luis 

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