[medmast]

Hi all,
I am trying to implement a new boundary condition that reads Internal fields U, P, and temperature from external solver and write these fields from OpenFOAM in a file for external solver.
to this end, i use the "externalCoupledMixedFvPatchField" boundary patch and i edit it.
i try the following code to write data in OpenFOAM fields:

 const volScalarField& Pressure= this->db().objectRegistry::lookupObject<volScalarField>("p");
   const volVectorField& Velocity= this->db().objectRegistry::lookupObject<volVectorField>("U");
   const volScalarField& Temperature= this->db().objectRegistry::lookupObject<volScalarField>("T");


    forAll(this->patch(), facei)
     {
             // define mesh on patch
             const fvMesh& mesh = this->patch().boundaryMesh().mesh();


                   // cell related to current face
                 label celli =this->patch().faceCells()[facei];

                  // define opposite face to patch face//
                 label oppfacei =mesh.cells()[celli].opposingFaceLabel
                                      (facei+this->patch().patch().start(),mesh.faces());
                 // define neighbour cell centre cellCentreN
                 vector cellCentreN = mesh.cellCentres()[mesh.owner()[oppfacei]];

                 // define patch cell centre cellCentre0
                 vector cellCentreO = mesh.cellCentres()[mesh.neighbour()[oppfacei]];


                 // cell lable of  cell
                 label CellP =mesh.findCell(cellCentreO);

 Pressure.internalField()[CellP] = "new value";


         }

Here I have error that Pressure field constant it, and when I try to define it as volScalarField, I can't define it with objectRegistry.
has anyone the idea, how i can change internal fields U,P and T within a boundary patch?
Thank you
iman