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-   -   DES with k-omega (http://www.cfd-online.com/Forums/openfoam-solving/103714-des-k-omega.html)

Jane L June 25, 2012 02:30

DES with k-omega
 
Hello!

For modeling an unsteady stall phenomenom, I'd like to use DES which uses k-omega in the near-wall region as RAS model. I just found the original DES with Spalart-Allmaras in OpenFOAM 2.1.0.
Before I start programming: Is there a method in OpenFOAM (maybe in .x or .dev) for DES with k-omega or did anyone of you implement this before?

Thanks in advance!

Jane L November 1, 2012 07:44

1 Attachment(s)
Hi Foamers!

Finally I finished the programming of the turbulence models which you can find in the attached archive.

This file contains the source code for the tree turbulence models DES, DDES and IDDES with k-w as SGS model (instead od Spalart Allmaras).

The turbulence models where tested with OpenFOAM 2.1.1 and gave fair results for airfoils with very high angles of attack. Lift and drag was compared to experimental values given in the paper "Detached-Eddy Simulation of an airfoil at high angles of attack" by Garbaruk, Shur, Strelets and Travin. The averaged aberration in lift and drag for angles of attack of 45 and 60 degree was always below 10%.

All turbulence models include an extra function "RANSregion" which gives an indication of the RANS- and LES-content of each cell. This function can be visualized with paraview and has positive values in cells where the turbulence is fully modelled by the RANS model. The RANS model works in SGS mode in cells with values lower 0.

I hope that this will be helpful. In case you use it, I would be glad if you give some feedback.

best regards!

mrs206 July 25, 2013 11:27

Hi Jane,

Thank you very much for writing these. They have been very useful in helping me to create a k-epsilon based DES model. I used the modifications proposed by Strelets for the turbulent length scale (i think this is the same method you have used?) but i have been unable to find a reference for the method you have used for the DDES model you have implemented.

Please could you point me in the right direction?

Many thanks,

Michael

Jane L July 26, 2013 02:48

Hi Michael.

The DDES model was developed and first described by: P. Spalart, S. Deck, M. Shur, K. Squires, M. Strelets, A. Travin.
in: A new version of detached-eddy simulation, resistant to ambiguous grid densities.
You can find the paper about IDDES via google:
M. Shur, P. Spalart, M. Strelets, A. Travin. A hybrid RANS-LES approach
with delayed-DES and wall-modelled LES capabilities

For might also have a look at:
http://www.sharcnet.ca/Software/Flue.../th/node91.htm
http://www.sharcnet.ca/Software/Flue...sec_iddes.html

I hope this helps! Kind regards

killsecond May 7, 2014 22:41

Hi Jane,
Have you tried to creat kOmegaSST based DES?


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