FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}

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

internalField   uniform (0 0 0);

boundaryField
{
    leftWall
    {
        type            noSlip;
    }

    rightWall
    {
        type            noSlip;
    }

    lowerWall
    {
        type            noSlip;
    }

    upperWall
    {
        type            pressureInletOutletVelocity;
        phi             phi;
        value           uniform (0 0 0);
    }

    defaultFaces
    {
        type            empty;
    }
}