[ch1]

Hi everyone,
I am using mapFields/meshToMesh functionality to map a scalar field at runtime between two meshes with inconsistent geometry. You can find images of source and target fields as well as their respective meshes in the attachments.
To produce the mapped target field I'm using the following code in foam-extend 4.0.:

// read the mapFieldsDict located in /case/system
IOdictionary mapFieldsDict
(
	IOobject
	(
		"mapFieldsDict",
		runTime.system(),
		runTime,
		IOobject::MUST_READ,
		IOobject::NO_WRITE,
		false
	)
);

HashTable<word> patchMap;
wordList cuttingPatches;
mapFieldsDict.lookup("patchMap") >> patchMap;
mapFieldsDict.lookup("cuttingPatches") >>  cuttingPatches;

// Create the interpolation scheme
meshToMesh fluidToEmInterp
(
    mesh, //source mesh
    targetMesh, //target mesh
    patchMap,
    cuttingPatches
);

// Interpolate field
fluidToEmInterp.interpolate
(
    targetField, //target field
    sourceField, //source field
    meshToMesh::INTERPOLATE 
);

In targetField.png you can actually see that mapFields extrapolated over those gaps of the sourceMesh except a thin stripe, which remained from the right gap. But this is actually not so critical.

What really bothers me is the extrapolation of the targetField over the right boundary of the sourceMesh as illustrated in overlappingMeshes.jpg.

How can I suppress this behavior?

Best regards
Christian

[ch1]

I want to note that I still didn't resolve this issue. However, I found that this issue only occurs if fields are mapped from the smaller to the bigger mesh. The other way around works fine.

My current workaround is the following:
Using two meshes that are identically built with blockMesh for the overlapping region.
If I then want to copy field values from source to target mesh I do the following

        forAll(T, idx)
        {
            const scalar& cellT = T[idx];
            Ttarget[idx] = cellT;
        }

where T is the source field and Ttarget is the target field. Then you can do whatever you want with the copied target field, you can even manipulate inside the loop, for example

        forAll(T, idx)
        {
            const scalar& cellT = T[idx];
            Ttarget[idx] = 5.0*cellT + 10; //some arbitrary function: y=5*x + 10
        }

In this related thread I described in more detail how to map fields between two meshes in foam-extend 4.0 using meshToMesh library:
Data exchange for internal field values between two different mesh