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Old   November 15, 2009, 07:11
Default About the nut wall function in RAS
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Shui Pei
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Hello everyone,
This is Pei, I have a question about the wall function of nu in RAS model, I found in the code,

nutw[faceI] = nuw[faceI]*(yPlus*kappa_/log(E_*yPlus) - 1.0)

However, the book I am reading says it should be

nutw[faceI] = nuw[faceI]*(yPlus*kappa_/log(E_*yPlus) )

Can angone explain the difference? Thank you very much!
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Old   October 28, 2011, 10:37
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Anne Gerdes
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Hey Pei,

In the log-Layer we can assume that nu_t >>nu
Therefore we can approximate

nuw[faceI]*(yPlus*kappa_/log(E_*yPlus) - 1.0) = nuw[faceI]*yPlus*kappa_/log(E_*yPlus)-nuw[faceI]
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