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Problems with YPlusRAS and wallShearStress

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Old   May 5, 2013, 08:42
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Ehsan
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in mutkWallFunctionFvPatchScalarField the equation uses for y-plus is related to y-star not y-plus

Code:
Code:
y-star=pow(0.09,0.25)*sqr(k)*nearDist()/mu
Code:
Code:
y-plus=rho*u_star*y/mu which u*=aqrt(taw_w/rho)
y-star is related to turbulent kinetic energy while y-plus relates to friction velocity(that relates to wall skin friction in its own)

in the code of mut
:
Code:
Code:
forAll(mutw, faceI)     {         label faceCellI = patch().faceCells()[faceI];          scalar yPlus =             Cmu25*y[faceI]*sqrt(k[faceCellI])/(muw[faceI]/rhow[faceI]);          if (yPlus > yPlusLam_)         {             mutw[faceI] = muw[faceI]*(yPlus*kappa_/log(E_*yPlus) - 1);         }     }
thanks.
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