tmp< GeometricField< typename outerProduct< vector, Type >::type, fvPatchField, volMesh >> grad(const GeometricField< Type, fvsPatchField, surfaceMesh > &ssf)
tmp< GeometricField< Type, fvPatchField, volMesh > > average(const GeometricField< Type, fvsPatchField, surfaceMesh > &ssf)
Area-weighted average a surfaceField creating a volField.