[Zymorui]

Dear Foamers,
I accessed the standard RANS turbulence models (SpalartAllmaras,kEpsilon,kOmega,kOmegaSST) in terms of their capability to reproduce the correct reattachment length for the pitzDaily tutorial case.

To increase the closeness to reality of the inlet conditions, I used the mesh from the pitzDailMapped tutorial case (Mesh M1).

The results on Mesh M1 with wall functions agree well with the experimental data from Pitz and Daily
https://doi.org/10.2514/3.8290. (See attached figure)

Additionally I refined the mesh to y+ ~ 1 at the walls with a cell2cell expansion factor of 1.2 with rising up to 100*y+ in the core region, calling it Mesh M2 to use without wall functions.

Unfortunatly the reattachment length on M2 without wall functions gets overestimated for all turbulence model but kEpsilon, as can be observed in the attached graph.

This is inexpected as the resolution of the boundary layer should have increased the accuracy and not impaired the results. I tried all different kind of settings for the wall boundary conditions but none seemed to have an impact. Nor any change in discretization schemes (I tried a few) or mesh refinement or coarsening.

Any further suggestions or experiences what could cause this offset in the reattachment length?

Settings and further information on the case:
fvSchemes

ddtSchemes
{
    default         steadyState;
}

gradSchemes
{
    default         Gauss linear;
    grad(U)         cellMDLimited Gauss linear 1;
    grad(nuTilda)   cellMDLimited Gauss linear 1;
}

divSchemes
{
    default         none;
    div(phi,U)      bounded Gauss linear;
    div(phi,k)      bounded Gauss linear;
    div(phi,epsilon)  bounded Gauss linear;
    div(phi,omega)  bounded Gauss linear;
    div((nuEff*dev2(T(grad(U))))) Gauss linear;
    div(phi,nuTilda) bounded Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear corrected;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default         corrected;
}

wallDist
{
    method meshWave;
}

fvSolution

solvers
{
    p
    {
        solver          GAMG;
        tolerance       1e-06;
        relTol          0.1;
        smoother        GaussSeidel;
    }

    pFinal
    {
        $p;
        tolerance       1e-6;
        relTol          0;
    }

    Phi
    {
        $p;
    }

    "(U|nuTilda|k|epsilon|omega)"
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        tolerance       1e-08;
        relTol          0.1;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 1;
    residualControl
    {
        p               1e-5;
        U               1e-5;
    k               1e-5;
    epsilon           1e-5;
        omega           1e-5;
    nuTilda           1e-5;
    }
}

potentialFlow
{
    nNonOrthogonalCorrectors 10;
}

relaxationFactors
{
    p               0.3;
    U               0.5;
    nuTilda         0.5;
    k               0.5;
    epsilon           0.5;
    omega           0.5;
}

cache
{
    grad(U);
}

boundary conditions at wall patches
All models:nut - nutLowReWallFunction
SpalartAllmaras: nuTilda - fixedValue 0
kEpsilon: k - fixedValue 1e-12
kEpsilon: epsilon - epsilonWallfuncion
kOmega: k - fixedValue 1e-12
kOmega: omega - omegaWallfuncion
kOmegaSST: k - fixedValue 1e-12
kOmegaSST: omega - omegaWallfuncion