[sandrobrad]

Hi there!
I am having some troubles trying to validate cd and cl numbers of naca0012 given the following boundary conditions using komegasst:
k

internalField   uniform 3.98e-5;//funciona con 7.2599
boundaryField
{

    inlet
    {
        type            fixedValue;
        value $internalField;
    }


outlet
    {
        type            zeroGradient;
    }



    walls
    {
        type kqRWallFunction;
        //type           kLowReWallFunction;//No es una wall function 
        value        $internalField;
    }



    frontAndBack
    {
        type            empty;
    }
}

nut

internalField   uniform 1.10e-5;

boundaryField
{
    inlet
    {
        type            calculated;
        value  $internalField;
    }

    outlet
    {
        /*
        type            calculated;
        value  $internalField;
        */
        type zeroGradient;
    }
    walls
    {
        type            nutkWallFunction;
        value           $internalField;//Valor muy pequeño por no poner 0 
    }

    "interface.*"
    {
        type            empty;
    }
}

OMEGA

internalField   uniform 3.62;//Esta bien este valor?//49701 funciona

boundaryField
{
    inlet
    {
        type            fixedValue;
        value $internalField;
    }
outlet
    {
        type            zeroGradient;
    }



    walls
    {
        type            omegaWallFunction;
        Cmu        0.09;
        kappa        0.41;
        E        9.8;
        beta1        0.075;
        value        uniform 0.0035;
    }



    frontAndBack
    {
        type            empty;
    }
   
}

U

internalField    uniform ( 51.4815 0 0 );
//uniform (51.28559735 4.48690837 0); //  ( Ubar*cos(5) Ubar*sin(5) 0)

boundaryField
{
    inlet
    {
        type            freestreamVelocity;
        freestreamValue $internalField;
    }

    outlet
    {
        type            freestreamVelocity;
        freestreamValue $internalField;
    }
    walls
    {
        type            noSlip;
    }

    "interface.*"
    {
        type            empty;
    }
}

After several simulations my mesh has y+ = 8.82 averaged and I would like to improve my simulations beacause I've got so high residuals values Do you know how can I improve my residuals??
The cl and cd values that I 've obtained is 0.00401141 0.011854


I am suspecting about the fvschemes and the fvsolution. Please , could you check out that files and tell me if that schemes are appropiate for my simulation?



Control Dict

application     simpleFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime        4000;

deltaT          1;

writeControl    timeStep;

writeInterval   100;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;




functions
{

    momErr
    {
        type            momentumError;
        libs            (fieldFunctionObjects);
        executeControl  writeTime;
        writeControl    writeTime;
    }

    contErr
    {
        type            div;
        libs            (fieldFunctionObjects);
        field           phi;
        executeControl  writeTime;
        writeControl    writeTime;
    }


    turbulenceFields1
    {
        type            turbulenceFields;
        libs            (fieldFunctionObjects);
        fields
        (
            k
            epsilon
            nut
            nuEff
            R
            devReff
            L
            I
        );

        executeControl  writeTime;
        writeControl    writeTime;
    }

    mag1
    {
        type            mag;
        libs            (fieldFunctionObjects);
        field           turbulenceProperties:R;

        result          magR;
        executeControl  writeTime;
        writeControl    writeTime;
    }

    forceCoeffs1
    {
        type            forceCoeffs;

        libs            ("libforces.so");

        writeControl    timeStep;
        timeInterval    1;
        aoa         5;
        log             yes;

        patches         ("walls");
        rho             rhoInf;      // Indicates incompressible
        rhoInf          1.225;           // Redundant for incompressible
        
       liftDir (0 1 0);
       dragDir (1 0 0);
/*
        liftDir         (-0.08715574275 0.9961946981 0);
        dragDir         (0.9961946981  0.08715574275  0);

*/
        CofR            (0.72 0 0);  // Axle midpoint on ground
        pitchAxis       (0 1 0);
        magUInf         51.4815;
        lRef            1;        // Wheelbase length
        Aref            0.3;        // Estimated
        /*
        binData
        {
        nBin        20;          // output data into 20 bins
        direction   (1 0 0);     // bin direction
        cumulative  yes;
        }
        */
    }
    yPlus
    {
        type            yPlus;
        libs            (fieldFunctionObjects);
        writeControl    writeTime;
        patches         (wall);
    }
    cellCentres
    {
        type            writeCellCentres;
        libs            (fieldFunctionObjects);
        writeControl    writeTime;
    }

    residuals
    {
        type            solverInfo;
        libs            (utilityFunctionObjects);
        fields          (".*");
    }
    

}

fvSchemes

ddtSchemes
{
    default         steadyState;
}

gradSchemes
{
    default         Gauss linear;

}

divSchemes
{
    default         none;
    div(phi,U)      bounded Gauss upwind;//linearUpwind grad(U);
    turbulence      bounded Gauss upwind;
    //turbulence      bounded Gauss limitedLinear 1;
    div(phi,k)      $turbulence;
    div(phi,omega)  $turbulence;
    
div(phi,nuTilda) bounded Gauss linearUpwind grad(nuTilda);
    div((nuEff*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear corrected;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default         corrected;
}

wallDist
{
    method meshWave;
}

fvSOLUTIONS

solvers
{
    p
    {
        solver          GAMG;
        tolerance       1e-06;
        relTol          0.01;
        smoother        GaussSeidel;
    }

    U
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps         2;
        tolerance       1e-08;
        relTol          0;
    }

    nuTilda
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps         2;
        tolerance       1e-08;
        relTol          0.01;
    }
    "(k|epsilon|R)"
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-08;
        nSweeps    2;
        relTol          0;
    }

    omega
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-08;
        relTol          0;
         nSweeps    2;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 0;

    residualControl
    {
        p               1e-5;
        U               1e-5;
        nuTilda         1e-5;
        "(k|epsilon|omega)" 1e-6;
    }

}

relaxationFactors
{
    fields
    {
        p               0.3;
    }
    equations
    {
        U               0.7;
        k               0.7;
        epsilon         0.7;
        nuTilda         0.8;
        omega           0.7;
    }
 }

PD: I dont know why in the beginning my residuals oscilates badly. Thats all. Thanks in advance and don't hesitate if you want ask me something.

[mAlletto]

Did you know this https://www.openfoam.com/documentati...irfoil-2d.html

[mAlletto]

If you need a discussion about how to simulate a wall resolved case with a k omega set you can look at this k-omega SST for wall-resolved TBL, problem with log layer..

For a y+ of 8 better use nutUSpalding b.c. since nutk is only valid in the log layer

[sandrobrad]

Hi Michael ,
I already know about that simulation. Moreover, that sim I've used it in order to learn how to use the SpalartAllmaras. Eventually, I was able to achieve good results using it. However, I'm trying to simulate with that boundary conditions (U,nu,rho...) using the kOmegaSST turbulence model.Like I said, using this model I'm getting trouble in the convergence. Thanks for ur reply btw.
Best Regards.