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Compressible flow issues in rhoCentralFoam solver

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Old   April 16, 2017, 17:51
Default Compressible flow issues in rhoCentralFoam solver
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sibo
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Dear All,

I was using rhoCentralFoam solver to calculate the compressible flow around an airfoil. Ma=0.75, T=260K and P=85000.
The simulation looks good at the beginning, the pressure plot at the beginning is posted here.
But since the simulation does not converge, i keep it running and something weird happened here. As shown in the picture, the cells next to the inlet boundary has a very high temperature and pressure. Also, the shock at the airfoil looks more dissipated than before.

Can anybody help me with this? Thanks in advance!
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File Type: png begin.png (57.3 KB, 29 views)
File Type: png end1.png (67.7 KB, 27 views)
File Type: png end2.png (40.7 KB, 28 views)
File Type: png end3.png (114.8 KB, 27 views)
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Old   April 16, 2017, 17:54
Default boundary conditions
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The boundary conditions I am using in this case:
P:
Code:
boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform 85418.9;
    }

    outlet
    {
        type            zeroGradient;
       // value           uniform 85418.9;
    }

    walls
    {
        type            slip;
    }

    defaultFaces
    {
        type            empty;
    }
}
U:
Code:
boundaryField
{
    inlet
    {
        type            freestream;
        freestreamValue uniform (241.84 16.84 0);
    }

    outlet
    {
        type            freestream;
        freestreamValue uniform (241.84 16.84 0);
    }

    walls
    {
        type            slip;
        //type            fixedValue;
        //value           uniform (0 0 0);
    }

    defaultFaces
    {
        type            empty;
    }
}
T:
Code:
boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform 260;
    }

    outlet
    {
        type            zeroGradient;
       // value           uniform 260;
    }

    walls
    {
        type            slip;
    }

    defaultFaces
    {
        type            empty;
    }
}
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Old   April 16, 2017, 17:55
Default fvSchemes and fvSolutions
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fvSchemes:
Code:
fluxScheme      Kurganov;

ddtSchemes
{
    default         Euler;
}

gradSchemes
{
    default         Gauss linear;
}

divSchemes
{
    default         Gauss upwind;
  //  div(phi,nuTilda) Gauss linearUpwind grad(nuTilda);
    div(tauMC)      Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear corrected;
}

interpolationSchemes
{
    default         linear;
    reconstruct(rho) Gamma  1.0;
    reconstruct(U)   GammaV 1.0;
    reconstruct(T)   Gamma  1.0;
}

snGradSchemes
{
    default         corrected;
}
fvSolutions:
Code:
solvers
{
    rho
    {
        solver          diagonal;
    }

    rhoU
    {
        solver          diagonal;
    }

    rhoE
    {
        solver          diagonal;
    }

    U
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps         2;
        tolerance       1e-09;
        relTol          0.01;
    }

    e
    {
        $U;
        tolerance       1e-08;
        relTol          0.01;
    }
}
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Old   April 23, 2017, 23:09
Default
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Modified Bcs and it works now.
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Old   May 6, 2017, 04:17
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Xu Yiming
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Quote:
Originally Posted by sibo View Post
Modified Bcs and it works now.
hi sibo

Which BC has you changed ,can you post your case here? Thanks~

Yiming
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Old   May 10, 2017, 17:19
Default
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Quote:
Originally Posted by ousoweak View Post
hi sibo

Which BC has you changed ,can you post your case here? Thanks~

Yiming
I used totalpressure for pressure. Also pay attention to the grid.

Last edited by sibo; May 11, 2017 at 14:13.
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airfoil, compressible, rhocentralfoam

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