[elmo555]

Dear foamers,

I'm trying to interpolate a surfaceVectorField to pointVectorField and then write it to a output file with the following code, but nothing gets written:

pointVectorField sensPointVec
(
    IOobject
    (
        "sensPointVec",
        runTime.timeName(),
        mesh,
        IOobject::NO_READ,
        IOobject::AUTO_WRITE
    ),
    pointMesh::New(mesh),
    dimensionedVector("(0,0,0)", dimless, vector::zero),
    "fixedValue"
);

            PrimitivePatchInterpolation<primitivePatch> patchInterpolator
            (
                mesh.boundaryMesh()[bi]
            );

            vectorField interpSensPointVec = patchInterpolator.faceToPointInterpolate(sensSurfaceVec.boundaryField()[bi]);
            Info << "interpSensPointVec " << interpSensPointVec << endl;
            sensPointVec.boundaryFieldRef()[bi] = interpSensPointVec;

The code compiles and runs and the new vectorField interpSensPointVec is filled with data (Info prints tons of data to the screen). But the output file sensPointVec contains just the initially set values and not the ones written into sensPointVec.boundaryFieldRef()[bi]:

boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    outlet
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
...

Any help is appreciated!

[elmo555]

I think I found the solution, you just need to replace the = in the assignment with ==

            sensPointVec.boundaryFieldRef()[bi] == interpSensPointVec;

An explanation for the difference between = and == in boundary condition assignment can be found in this thread.