[soonic]

Dont know how to hide or delete this for now, but i found mismatched BC. But maybe I will need help later. Thanks for visit.

Hello,

I am solving water flowing in pipe in steadyState by simpleFoam. I have Re~20000. Velocities 1÷2m/s. I am unable to converge with my case. I did a comparison of case with laminar vs. k-eps regime, and tetra vs. polyhedral mesh (produced by polyDualMesh from that tets). Could you help me to tune up fvSchemes and fv Solution, please ? Or is it grid or BC related issue ?


I have read and tried several ideas written on the forum but no big success. I also divided the case in solving bended knee only, T-juction only. They have converged, but now the solution blows up e.g. on k and epsilon bounding and time step continuity error at some point of computation. I would like to compute temperature fields later on, but I am unable to solve flow for now.

my case:


boundaries are like: green inlet (hot water); red outlet (hot water); red inlet(cold water); blue outlet(cold water). Hot outlet and cold inlet is the same diameter and mass flow.
Files from system folder are attached. CheckMesh for both meshes as well. BCs are in the end of post. Now I will show resiaduals. Maybe somebody knows what happens there.

Thank you



http://soonic.cesnak.org/cfd/lam_pol...b_polyTurb.png




p

internalField   uniform 0;

boundaryField
{
    inh
    {
         type            zeroGradient;
    }
    inc
    {
        type            zeroGradient;
    }    
    outh
    {
    type            fixedValue;
        value           uniform 0;
    }
    outc
    {
         type            zeroGradient;
    }
    stena
    {
        type            zeroGradient;
    }

U

internalField   uniform (0 0 0 );

boundaryField
{
    inh
    {
        type            fixedValue;
        value           uniform (0.504 0 0); //Value is half scaled for laminar case
    }
    outh
    {
        type            fixedValue;
        value           uniform (0 1.7654 0); //Value is half scaled for laminar case
    }
    inc
    {
        type            fixedValue;
        value           uniform (0 -1.7654 0); //Value is half scaled for laminar case
    }
    outc
    {
        type            zeroGradient;
    }
    stena
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
}

k

internalField   uniform 0.004;

boundaryField
{
    inh
    {
        type            turbulentIntensityKineticEnergyInlet;
        intensity       0.04726;
        U               U;
        phi             phi;
        value           uniform 0.000852;
    }
    outh
    {
        type            turbulentIntensityKineticEnergyInlet;
        intensity       0.04229;
        U               U;
        phi             phi;
        value           uniform 0.00836;
    }
    inc
    {
        type            turbulentIntensityKineticEnergyInlet;
        intensity       0.04229;
        U               U;
        phi             phi;
        value           uniform 0.00836;
    }
    outc
    {
        type            zeroGradient;
    }
    stena
    {
        type            kqRWallFunction;
        value           uniform 0.001;
    }

epsilon

internalField   uniform 100;

boundaryField
{
    inh
    {
        type            turbulentMixingLengthDissipationRateInlet;
        mixingLength    0.034678;
        phi             phi;
        k               k;
        value           uniform 0.0001179;
    }
    outh
    {
        type            turbulentMixingLengthDissipationRateInlet;
        mixingLength    0.02407;
        phi             phi;
        k               k;
        value           uniform 0.0052217;
    }
    inc
    {
        type            turbulentMixingLengthDissipationRateInlet;
        mixingLength    0.02407;
        phi             phi;
        k               k;
        value           uniform 0.0052217;
    }
    outc
    {
        type            zeroGradient;
    }
    stena
    {
        type            epsilonWallFunction;
        value           uniform 0.001;
    }
}