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Old   July 7, 2012, 13:35
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Hello everbody,

I am bothering with the SST-Model, but I can't get good explanations in the web. Can anyone describe me the main differences of both models and why k-omega is used near boundary layer and k-epsilon in outer region.

How were all the constants in a k-epsilon-model determined (see attachment)?

One last question, the Θ-term is the heat-flux, isn't it?

Attached you can find the equations I am talking about.

Thank you!

Best Regards
Thomas
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Old   July 9, 2012, 03:23
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you can find all your answers in the document of the Fluent help~
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Old   July 9, 2012, 04:37
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Quote:
Originally Posted by thda7 View Post
Hello everbody,

I am bothering with the SST-Model, but I can't get good explanations in the web. Can anyone describe me the main differences of both models and why k-omega is used near boundary layer and k-epsilon in outer region.

How were all the constants in a k-epsilon-model determined (see attachment)?

One last question, the Θ-term is the heat-flux, isn't it?

Attached you can find the equations I am talking about.

Thank you!

Best Regards
Thomas
Because K-Epsilon model is not designed for the integration to wall and is good for core flow. On the other hand K-omega model has no difficulty in integrating to wall without any extra effort. But performs poorly in core region and also suffers from the free stream dependency. So by combining both models we get the advantages of both models.

For details I would to recommend turbulence modelling by Wilcox.
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Old   July 17, 2012, 06:29
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Because K-Epsilon model is not designed for the integration to wall and is good for core flow. On the other hand K-omega model has no difficulty in integrating to wall without any extra effort. But performs poorly in core region and also suffers from the free stream dependency. So by combining both models we get the advantages of both models.

For details I would to recommend turbulence modelling by Wilcox.
Far can you explain the meaning of free stream dependency in detail using some practical flow example?
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