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wall functions and boundary conditions in OF 1.7.1

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Old   May 4, 2011, 20:27
Default wall functions and boundary conditions in OF 1.7.1
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cristobal albarracin
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Hi everyone,
I am running a case of flow past an airfoil using simleFoam and the kOmegaSST turbulence model. I have a y+ of less than 1 everywhere. When I use wall functions it runs ok, but it doesn't quite reach the free stream value of k that I specified in the boundary conditions. When I use the FixedValue condition at the wall, the boundary layer gets way too thick. I am not sure what the value of omega should be at the wall, in theory it should be 0, because k=0, but when I specify that value the solver crashes. I tried a very small but non-zero value and it runs, but with the BL grows too thick.
I am not sure if using wall functions is justified if y+ is less than 1, can anyone give me some advice?

Cheers.
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Old   May 5, 2011, 10:50
Default Wall functions
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Arnout
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For turbulance, there are two methods close to the wall. Wall functions for y+ > 30 or integrating to the wall. See

http://www.cfd-online.com/Wiki/Near-...k-omega_models

Good luck!
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Old   May 6, 2011, 04:10
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Roman Thiele
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if you wanna run this case in low Re approach, consider the following link Near wall treatment in k-omega SST it will give you the right boundary conditions and some suggestions on how to use the OpenFOAM kOmegaSST model in a low Re (y+<1)
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