Hi friend, I have a trouble
 

Hi friend,

I have a trouble which I want to modify the U. I mean I want to keep the initial U to a new variable and after solver, I like to add this quatity to U again. But there are some errors. Could you please help me.

volScalarField Uin = UEqn.A();
...
U += Uin;

Errors:

icoFoam.C:120: error: no match for ˜operator+=U in ˜U += Uin"
/home/liu/OpenFOAM/OpenFOAM-1.2/src/OpenFOAM/lnInclude/GeometricField.C:1238: note: candidates are: void Foam::GeometricField<type,>::operator+=(const Foam::GeometricField<type,>&) [with Type = Foam::vector, PatchField = Foam::fvPatchField, GeoMesh = Foam::volMesh]
/home/liu/OpenFOAM/OpenFOAM-1.2/src/OpenFOAM/lnInclude/GeometricField.C:1238: note: void Foam::GeometricField<type,>::operator+=(const Foam::tmp<foam::geometricfield<type,> >&) [with Type = Foam::vector, PatchField = Foam::fvPatchField, GeoMesh = Foam::volMesh]
/home/liu/OpenFOAM/OpenFOAM-1.2/src/OpenFOAM/lnInclude/GeometricField.C:1238: note: void Foam::GeometricField<type,>::operator+=(const Foam::dimensioned<type>&) [with Type = Foam::vector, PatchField = Foam::fvPatchField, GeoMesh = Foam::volMesh]
make: *** [Make/linuxGcc4Opt/icoFoam.o] Error 1