tmp< GeometricField< Type, fvPatchField, volMesh > > div(const GeometricField< Type, fvsPatchField, surfaceMesh > &ssf)
tmp< GeometricField< Type, fvPatchField, volMesh > > DDt(const surfaceScalarField &phi, const GeometricField< Type, fvPatchField, volMesh > &psi)