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k-omega simulation without wall functions

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Old   January 21, 2010, 14:10
Default k-omega simulation without wall functions
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Vesselin Krastev
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Hi every body, I'm an almost brand new OF user, and I have to simulate a simple 2d aerodynamics case, with a solid profile immersed into an airflow. The simulation has to be performed with a k-omega turbulence model but without any wall functions. My intention is to use the pisoFoam solver (I have already used it, but with a k-epsilon model with wall functions). So the questions are:

1) How can I (in general terms) perform a RANS simulation in OF without wall functions? What kind of BC's may I set (especially at the solid walls)?

2) How can I do it with a k-omega model (both in the standard or sst versions)?

Thank you in advance

ps-the case in question is made up by a rectangular ambient, with inlet and outlet sections, in which the profile is immersed. Obviously the upper and lower solid boundaries of the ambient are far distant from the profile itself.
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Old   January 24, 2010, 17:51
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Hallo,

look at this posting:
low reynolds re turbulence boundary and yPlus values

You have to set for k and epsilon (omega) values to very small values for the wall boundary conditions. For inlet and outlet conditions you can use the same as for high reynolds turbulence models.
Also you have to set nut to calculated.

Regards

Thomas
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Old   January 24, 2010, 18:45
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BastiL
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Quote:
Originally Posted by Thomas Baumann View Post
You have to set for k and epsilon (omega) values to very small values for the wall boundary conditions. For inlet and outlet conditions you can use the same as for high reynolds turbulence models.
Also you have to set nut to calculated.
Thomas
And you have to use a low-Re Turbulence model.... Afaik there is no low-Re k-omega model present in 1.6 and 1.6.x. Am I wrong?

Regards BastiL
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