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gamma-ReTheta turbulence model for predicting transitional flows

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Old   December 4, 2018, 22:45
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kevin
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Quote:
Originally Posted by klausb View Post
Hello,

please describe the simulation you are planning (airfoil, Reynolds number, Tu...) and your setup problems.

In general, it's a good idea to use a working case which uses a similar turbulence model as a starting point and make adjustments rather than creating a new setup from scratch. You could use a steady state (simpleFoam) case which uses e.g. kOmegaSST if you have one and you should look at the tutorials maybe there's a case using the model you want to use.

To get an idea about calculating the model specific initial values (specific 0 folder content for gammaInt and ReThetat) read the academic papers describing the model:

Langtry, R. B., & Menter, F. R. (2009).
Correlation-based transition modeling for unstructured parallelized
computational fluid dynamics codes.
AIAA journal, 47(12), 2894-2906.

Menter, F. R., Langtry, R., & Volker, S. (2006).
Transition modelling for general purpose CFD codes.
Flow, turbulence and combustion, 77(1-4), 277-303.

Langtry, R. B. (2006).
A correlation-based transition model using local variables for
unstructured parallelized CFD codes.
Phd. Thesis, Universität Stuttgart.

Klaus
Hello Klaus, could you please teach me how to set up the airfoil calculation with the KomegaSST transition model? Thank you very much. The following figures are my setup for U, k, ReThetat, maybe there have some errors.


u.JPG

k.JPG

ReThetat.JPG
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Old   December 5, 2018, 11:30
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Hi Kevin,


What airfoil do you have in mind? NACA0015....

I assume you're using an o-mesh but where's the inlet in your definitions?!

What are your mesh parameters incl. y+, #cells along the surface (about 300?), #cells in z-direction (about 140?)?
Here you can calculate your case specific turbulence properties: https://www.cfd-online.com/Tools/turbulence.php


Please post your boundary file from the constant/polyMesh directory.


Klaus
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Old   December 9, 2018, 22:20
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Quote:
Originally Posted by klausb View Post
Hi Kevin,


What airfoil do you have in mind? NACA0015....

I assume you're using an o-mesh but where's the inlet in your definitions?!

What are your mesh parameters incl. y+, #cells along the surface (about 300?), #cells in z-direction (about 140?)?
Here you can calculate your case specific turbulence properties: https://www.cfd-online.com/Tools/turbulence.php


Please post your boundary file from the constant/polyMesh directory.


Klaus
Hi Klaus:

Thank you for your reply. My calculated airfoil is DU-93-W-210.

I use icem to generated a C-H type mesh, it was realized as follows
(1) generate a 2d airfoil unstructured mesh in the x, y directions
(2) extrude the mesh in the z direction. Since openfoam only accept the 3d unstructured mesh.

For the inlet, it is a line in the 2d mesh. So, I delete in in the 3d mesh after
extruding. Is that right?

Please find the boundary information in the attached file. Thank you.


boundary.JPG
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Old   August 30, 2022, 12:50
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Quote:
Originally Posted by aloeven View Post
@salvatore

You have to compile a turbulence model as a library using: wmake libso

You can make a Make directory in the gammaThetatSST directory with two files: files and options.

files:
gammaReThetatSST.C
LIB = $(FOAM_USER_LIBBIN)/libGammaThetatSSTmodel

options:
EXE_INC = \
-I$(LIB_SRC)/turbulenceModels \
-I$(LIB_SRC)/transportModels \
-I$(LIB_SRC)/finiteVolume/lnInclude \
-I$(LIB_SRC)/meshTools/lnInclude \
-I$(LIB_SRC)/turbulenceModels/incompressible/RAS/lnInclude
LIB_LIBS =


To use it, you have to add to system/controlDict :
libs ("libGammaThetatSSTmodel.so");

This is well explained here:
http://openfoamwiki.net/index.php/Si...ry_/_Tutorials
or here:
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2008/implementTurbulenceModel.pdf

I would put the model not under applications, but of course you're free to choose.

Good luck.
Alex.
Could you send the files for compilation? wmake and clean?
I did not understand what you said.
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