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[OpenFOAM-2.1.0] kklOmega RAS Turbulence Model (low Re) |
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June 16, 2014, 09:38 |
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#61 |
Senior Member
M. Montero
Join Date: Mar 2009
Location: Madrid
Posts: 153
Rep Power: 17 |
Joe ferrari,
In your thesis, you stated that nut at wall should be zeroGradient. I also noticed that internal field is initialized to "zero". I am having a similar problem like you ( but using SimpleFoam) but I can not solve it changin nut to fixedValue. kl at the wake of the airfoil is very high and at the end, the solution diverges. |
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July 17, 2014, 04:20 |
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#62 |
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Ye Zhang
Join Date: Dec 2009
Location: Delft,Netherland
Posts: 92
Rep Power: 16 |
Dear Mojtab,
Do you set the omega boundary condition at the wall the same as the komega SST turbulence model? I also made this mistake. Change it to zeroGradient, and should be fine. Best regards Ye |
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July 17, 2014, 16:51 |
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#63 | |
Senior Member
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Quote:
Yes, that was the problem. Thank you for your kind response. With all the best wishes. Mojtaba
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Learn OpenFOAM in Persian SFO (StarCCM+ FLUENT OpenFOAM) Project Team Member Complex Heat & Flow Simulation Research Group If you can't explain it simply, you don't understand it well enough. "Richard Feynman" |
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September 11, 2014, 13:27 |
which airfoil
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#64 | |
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Alberto
Join Date: Sep 2013
Posts: 37
Rep Power: 12 |
Quote:
Hi, I was wondering if you can provide me some more information on the airfoil test case you were running referred in this post. What was the geometry?, Inlet conditions. Thanks in advanced Last edited by malv83; September 13, 2014 at 11:09. |
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June 17, 2016, 14:39 |
New model
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#65 |
Member
Alberto
Join Date: Sep 2013
Posts: 37
Rep Power: 12 |
After 8 years, there is a new version (or new model) of the k-kl-omega model.
There are a few problems with the k-kl-omega model in the farfield. One of them is the growth of Laminar Kinetic energy when separation occurs. Lopez and Walters have a paper (have not been published yet) correcting this issue: Maurin Lopez. D. K. Walters. “A recommended correction to the k-kl-omega transition sensitive eddy-viscosity model”. Journal of Fluid Engineering. This correction has to be made to the 2008 k-kl-omega model from now on. Now, Lopez and Walters also developed a new transitional model (k-omega-v2) as an alternative to the k-kl-omega one. This new model has more capabilities (it is more reliable) than the k-kl-omega model, especially in the farfield computations. Fortunately the paper for this new model is already publish. Maurin Lopez. D. K. Walters. “Prediction of transitional and fully turbulent free shear flows using an alternative to the laminar kinetic energy approach”. Journal of Turbulence, Vol 17, Iss. 3, 2016. If you see the papers, you will immediately see how the k-kl-omega model is not good for free shear flows, and how the new model corrects all those issues. From now on, k-kl-omega users have to start using the new k-omega-v2 model. Hope this helps |
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