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March 11, 2012, 08:57 
turbulent kinetic energy in TGV case

#1 
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Hello!
I try to use Twoequation  eddy viscosity model for TaylorGreen Vortex case with Re=3000. I use physical space code with weno3 scheme. I don't want to transport neither turbulent kinetic energy nor turbulent dissipation so I looking for an appropriate models. Kindly ask you to help me. 

March 11, 2012, 12:35 

#2 
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I'm not sure what you are trying to do and what you are asking for....so you are doing an LES, and you are looking for a SGS model? Is that it? I don't understand your comment about using the k eps model without using the appropriate transport equations.... ???


March 11, 2012, 14:23 

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March 11, 2012, 14:35 

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March 11, 2012, 14:59 

#5 
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Dear baraban,
I'm not sure if a RANS approach will get you anywhere with this problem. The TGV is highly unsteady and strongly governed by vortex interaction, so a RANS approach (which does not resolve any eddies) will not give you a good approximation. if you just want to check that, then RANS is fine, but for much else, LES will be needed! 

March 11, 2012, 16:03 

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I can also get some DNS results for evalution of turbulent kinetic energy and put it to the kepsilone model. Than I'll get the limit of prediction for that model for TGV case so I can compare the results of rough models for turbulent kinetic energy with that limit. I tried to find some models on google and on wos but failed. I also checked it in "Turbulent Flows" by Pope and didn't find the answer. May be you can suggest some other source of searching? I would really appreciate any help). 

March 12, 2012, 17:12 

#7 
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As previously stated by cfdnewbie, the TaylorGreen vortex case is usually studied to check model capabilities in predicting transition to turbulence in a setting which does not involve boundary conditions or walls. As long as i understand the TaylorGreen vortex case and the URANS turbulence models you wont get any help from any source as it has never been done with URANS. The reason is that it is really out of the modeling capabilities of the URANS approach so no one tryied to get an answer which could never be useful in practice. Nonetheless, you can clearly do the job in any case; just take any available reference on TGV and do the same simulation with your model of choice.
The first reference which comes in my mind is by Fauconnier et al., some work of Drikakis et al., Hickel and maybe someone at Stanford (try to look in the CTR material from the last 56 years) Also, the initialization of this flow is very easy (compared to HIT) so its everything really straight... except that you have to somehow set your initial condition for the URANS turbulence model. This is going to be awkward... 

Tags 
inviscid, kepsilon model, modeling cfd, turbulence, turbulence kinetic energy 
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