FoamFile
{
    version     2.0;
    format      binary;
    class       volVectorField;
    location    "0";
    object      b;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 0 -2 0 0 -1 0];

bz 10e-3;

internalField   uniform (0 0 $bz);

boundaryField
{
    ".*"
    {
        type            fixedValue;
        value           uniform (0 0 $bz);
    }
}

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