OpenFOAM计算管道内部泊肃叶流动需要的边界条件

泊肃叶流动为层流流动，在OpenFOAM中仅需要设计p和U边界条件：

p边界条件：

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5.x                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform 0;

boundaryField
{
    inlet
    {
        type            zeroGradient;
    }
    outlet
    {
        type            fixedValue;
        value           uniform 0;
    }
    wall
    {
        type            zeroGradient;
    }
}

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

U边界条件：

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5.x                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
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
{
    inlet
    {
        type            codedFixedValue;
        value           uniform (0 0 2);
        name            parabolicVelocity;
        code            #{
            // 下面三行为标准写法，一般不用修改
            const fvPatch& boundaryPatch = patch();
            const vectorField& Cf = boundaryPatch.Cf();
            vectorField& field = *this;
            // Umax为2倍的平均速度；p_ctr_x和p_ctr_y为进口中心点与坐标系原点的偏移量；R为圆管的半径
            scalar Umax = 4, p_ctr_x= 0, p_ctr_y = 0, R = 0.00125;
            forAll(Cf, faceI)
            {
                field[faceI] = vector(0,0,Umax*(1-(pow(Cf[faceI].x()-p_ctr_x,2)+pow(Cf[faceI].y()-p_ctr_y,2))/(R*R)));
            }
        #};
    }
    outlet
    {
        type            zeroGradient;
    }
    wall
    {
        type            noSlip;
    }
}

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