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yPlusRAS : result = 0

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Old   October 14, 2009, 15:43
Default yPlusRAS : result = 0
  #1
jmf
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Jean-Michel FONTAINE
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Hello dear all

Situation of a novice : I fail in using yPlusRAS
After running simpleFoam, yPLusRAS returns following message :
"Patch 0 named wall y+ : min: 0 max: 0 average: 0"

It creates a yPLus containing :
Code:
internalField   uniform 0;
boundaryField
{
    wall
    {
        type            calculated;
        value           uniform 0;
    }
    inlet
    {
        type            calculated;
        value           uniform 0;
    }
    outlet
    {
        type            calculated;
        value           uniform 0;
    }
and a file 'y' with non null values (almost one value per model node), of which the average is 0.38

What did I miss ?

Best regards

Jean-Michel
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Old   October 15, 2009, 05:34
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Daniel WEI (老魏)
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Since yPlus is calculated by
Code:
    if (isType<wallFvPatch>(curPatch))
    {
        Yp = pow(Cmu, 0.25)
            *y_[patchNo]
            *sqrt(k()().boundaryField()[patchNo].patchInternalField())
            /nu().boundaryField()[patchNo];
    }
in file RASModel.C

So, I am bold to guess something wrong with the k field, eg. you are missing it?
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Old   October 15, 2009, 16:16
Default yPlusRAS : result = 0
  #3
jmf
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Jean-Michel FONTAINE
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Hi Daniel

My k dictionary contains:
Code:
 inlet
    {
        type            fixedValue;
        value           uniform 3 ;
    }
    outlet
    {
        type            zeroGradient;
    }
    wall
    {
        type            kqRWallFunction;
        value           uniform 5;
    }
and Cmu = 0.09

Is following message from solver normal :
"smoothSolver: Solving for nuTilda, Initial residual = 0, Final residual = 0, No Iterations 0" ?

Thanks for your help
J-Michel
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Old   October 16, 2009, 03:36
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Tian
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Hi,

maybe you have to set the boundary patch to "wall"?

Byt
Thomas
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Old   October 17, 2009, 06:02
Default yPlusRAS : result = 0
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jmf
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Jean-Michel FONTAINE
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Hi Thomas

The boundary patches are set to "wall"

Thanks to everybody for the time

J-Michel
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