[Daniel_Khazaei]

Hello foamers

I am trying to simulate a simple problem which includes a single straight pipe.
The flow is laminar and incompressible (steady state). As for the boundary condition, I am using:

inlet: pressureInlet 1333.2 Pa
outlet: pressureOutlet 0 Pa

I can easily get convergence on fluent in a minute. (residual order 1e-6)


Now when I try the same case in OpenFOAM (same mesh), it gives me a hard time to converge, as I think its going to take even a day to reach convergence tolerance.(simpleFoam solver) here is my case setup in OpenFOAM ( the case is attached):

Boundary condition:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.5-dev                               |
|   \\  /    A nd           | Revision: 1736                                  |
|    \\/     M anipulation  | Web:      http://www.OpenFOAM.org               |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    FSI
    {
        type            zeroGradient;
    }
    OUTLET
    {
        type            fixedValue;
        value           uniform 0;
    }
    INLET
    {
        type            fixedValue;
        value           uniform 1333.2;
    }
}


// ************************************************************************* //

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.5-dev                               |
|   \\  /    A nd           | Revision: 1736                                  |
|    \\/     M anipulation  | Web:      http://www.OpenFOAM.org               |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    location    "0";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    FSI
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    OUTLET
    {
        type            zeroGradient;
    }
    INLET
    {
        type            zeroGradient;
    }
}


// ************************************************************************* //

Schemes:

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.3                                   |
|   \\  /    A nd           | Web:      http://www.openfoam.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/

FoamFile
{
    version         2.0;
    format          ascii;

    root            "";
    case            "";
    instance        "";
    local           "";

    class           dictionary;
    object          fvSchemes;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default steadyState;
}

gradSchemes
{
    default         cellMDLimited Gauss linear 0.5;
    grad(p)         cellMDLimited Gauss linear 0.5;
}

divSchemes
{
    default         none;
    div(phi,U)      Gauss linearUpwindV cellMDLimited Gauss linear 0.5;
    div((nuEff*dev(grad(U).T()))) Gauss linear corrected;
}

laplacianSchemes
{
    default         Gauss linear limited 0.5;
}

interpolationSchemes
{
    default         linear;
    interpolate(U)  linear;
}

snGradSchemes
{
    default         limited 0.5;
}

fluxRequired
{
    default         no;
    p;
}


// ************************************************************************* //

Am I missing something obvious in OpenFOAM setup?

you can download the case here: http://www.rodfile.com/w4xt9xwxesqo

thank in advance

regards