[khunyeu]

Dear Foamers,

I'm doing a scour channel flow with pisoFoam kOmegaSST, basically my BCs are as below, however numerical velocity result is not fit with experimental data (please see the attached figure).

I have y+ around 40 so I used wallFuntion at the bottom.
I have tried with many other BCs for U and p --> not better
changed fvSchemes to 2nd orders --> not better
changed to (much) finer mesh (checkMesh of both cases are OK) --> not better

The result is surprisingly good in scour hole but not good far the wall and far downstream, also my U at downstream is bigger than inlet velocity, which is wrong.

I'm not sure what to do to fix this, could anyone please have a look and any suggestion would be very appreciated.

0/U

inlet
    {
        type            fixedValue;
        value           uniform (0.405 0 0);
    }

    wall1
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    
    lowerWall
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }

    atmosphere
    {
        type                zeroGradient; 
    }

    outlet
    {
        type                zeroGradient;
    }
    
    frontAndBack
    {
        type            empty;
    }

0/p

inlet
    {
        type            zeroGradient;
    }

    wall1
    {
        type            zeroGradient;
    }
    
    lowerWall
    {
        type            zeroGradient;
    }

    atmosphere
    {
        type            zeroGradient;
    }
    
    outlet
    {
        
        type            fixedValue;
        value           uniform  0; 
    }

    frontAndBack
    {
        type            empty;
    }

0/k

inlet
    {
        type            fixedValue;
        value           uniform 0.000615; 
    }

    outlet
    {
        type            zeroGradient;
    }

    wall1
    {
        type            kqRWallFunction;
        value             uniform 0.000615;
    }
    
    lowerWall
    {
        type            kqRWallFunction;
        value             uniform 0.000615; 
    }

    atmosphere
    {
        type            zeroGradient;        
    }

    frontAndBack
    {
        type            empty;
    }

0/omega

inlet
    {
        type            fixedValue;
        value           uniform 1.078; 
    }

    outlet
    {
        type            zeroGradient;
    }

    wall1
    {
        type            omegaWallFunction;
        value           $internalField; 
    }
    
    lowerWall
    {
        type            omegaWallFunction;
        value           $internalField; 
    }

    atmosphere
    {
        type            zeroGradient;
    }

    frontAndBack
    {
        type            empty;
    }

0/nut

inlet
    {
        type            calculated;
        value             uniform 0;
    }

    outlet
    {
        type            calculated;
        value             uniform 0;
    }

    atmosphere
    {
        type            calculated;
        value             uniform 0;
    }

    wall1
    {
        type            nutkRoughWallFunction;
        value          uniform 0;
        Ks              uniform 0;
        Cs              uniform 0.5;
    }
    
    lowerWall
    {
        type            nutkRoughWallFunction;
        value          uniform 0;
        Ks              uniform 0.0012;
        Cs              uniform 0.5;
    }

    frontAndBack
    {
        type            empty;
    }

Thank you in advance.
Min.