[Gaetano]

Hello foam-devs.

I have a problem in controlling a custom BC from within the solver (OF 2.1.1).

The BC is a modification of partialSlip: I tried to implement a fixedValue in case valueFraction is 1, that is to have a no-slip condition with a moving wall. Below my modifications (in red).

partialFixedSlipFvPatchField.H:

template<class Type>
class partialFixedSlipFvPatchField
:
    public transformFvPatchField<Type>
{
    // Private data

        //- Fraction (0-1) of value used for boundary condition
        scalarField valueFraction_;
        Field<Type> refValueWall_;


public:

    //- Runtime type information
    TypeName("partialFixedSlip");

[...]

        // Return defining fields

            virtual scalarField& valueFraction()
            {
                return valueFraction_;
            }

            virtual const scalarField& valueFraction() const
            {
                return valueFraction_;
            }


//---------------------------------------------------
            virtual Field<Type>& refValueWall()
            {
                return refValueWall_;
            }

            virtual const Field<Type>& refValueWall() const
            {
                return refValueWall_;
            }

partialFixedSlipFvPatchField.C:

template<class Type>
Foam::partialFixedSlipFvPatchField<Type>::partialFixedSlipFvPatchField
(
    const fvPatch& p,
    const DimensionedField<Type, volMesh>& iF,
    const dictionary& dict
)
:
    transformFvPatchField<Type>(p, iF),
    valueFraction_("valueFraction", dict, p.size()),
    refValueWall_("refValueWall", dict, p.size())
{
    evaluate();
}

[...]

template<class Type>
void Foam::partialFixedSlipFvPatchField<Type>::evaluate
(
    const Pstream::commsTypes
)
{
    if (!this->updated())
    {
        this->updateCoeffs();
    }

    tmp<vectorField> nHat = this->patch().nf();

    Field<Type>::operator=
    (
       valueFraction_ * refValueWall_ +
        (1.0 - valueFraction_)
       *transform(I - sqr(nHat), this->patchInternalField())
    );

    transformFvPatchField<Type>::evaluate();
}

[...]

template<class Type>
void Foam::partialFixedSlipFvPatchField<Type>::write(Ostream& os) const
{
    transformFvPatchField<Type>::write(os);
    valueFraction_.writeEntry("valueFraction", os);
    refValueWall_.writeEntry("refValueWall", os);
}

For the sake of clarity, I'm also attaching the output of the commands:

• diff -y -W 180 partialFixedSlipFvPatchField.H $FOAM_SRC/finiteVolume/fields/fvPatchFields/derived/partialSlip/partialSlipFvPatchField.H
• diff -y -W 180 partialFixedSlipFvPatchField.C $FOAM_SRC/finiteVolume/fields/fvPatchFields/derived/partialSlip/partialSlipFvPatchField.C

My problem is that I'm not able to assign a value to the field refValueWall:

    label patchID = mesh.boundaryMesh().findPatchID("wall");
    if(patchID == -1)
    {
        Info << "patch not found" << endl;
        return 0;
    }

    partialFixedSlipFvPatchVectorField& Upatch =
            refCast<partialFixedSlipFvPatchVectorField>
            (
                U.boundaryField()[patchID]
            );

    Upatch.valueFraction() = alpha1.boundaryField()[patchID];
    Upatch.refValueWall() = myField.boundaryField()[patchID];

The problem is in the blue line: I'm able to set Upatch.valueFraction() but not Upatch.refValueWall().

When I try to compile I get this error:


Make/linux64GccDPOpt/myInterFoam.o: In function `Foam::partialFixedSlipFvPatchField<Foam::Vector<d ouble> >& Foam::refCast<Foam::partialFixedSlipFvPatchField<F oam::Vector<double> >, Foam::fvPatchField<Foam::Vector<double> > >(Foam::fvPatchField<Foam::Vector<double> >&)':
myInterFoam.C:(.text._ZN4Foam7refCastINS_28partial FixedSlipFvPatchFieldINS_6VectorIdEEEENS_12fvPatch FieldIS3_EEEERT_RT0_[Foam::partialFixedSlipFvPatchField<Foam::Vector<do uble> >& Foam::refCast<Foam::partialFixedSlipFvPatchField<F oam::Vector<double> >, Foam::fvPatchField<Foam::Vector<double> > >(Foam::fvPatchField<Foam::Vector<double> >&)]+0xdd): undefined reference to `Foam::partialFixedSlipFvPatchField<Foam::Vector<d ouble> >::typeName'
collect2: ld returned 1 exit status


I can't figure out the problem. Does anyone have a clue?

Thanks in advance,
Gaetano

[Gaetano]

Seems I was wrong; the problem seems to be in:

    label patchID = mesh.boundaryMesh().findPatchID("wall");
    if(patchID == -1)
    {
        Info << "patch not found" << endl;
        return 0;
    }

    partialFixedSlipFvPatchVectorField& Upatch =
            refCast<partialFixedSlipFvPatchVectorField>
            (
                U.boundaryField()[patchID]
            );

    Upatch.valueFraction() = alpha1.boundaryField()[patchID];
    Upatch.refValueWall() = myField.boundaryField()[patchID];

If I use the partialSlip condition it works like a charm, but I'm not able to use my partialFixedSlip BC.

I'm also trying another path: how about reading a surfaceVectorField calcolated in the main solver from within the BC?

Any suggestion?

[Gaetano]

Ok, I was trying to reinvent the wheel: mixedFixedValueSlip, in $FOAM_SOLVERS/compressible/rhoCentralFoam/BCs/mixedFixedValueSlip.

I will study its implemention and come back in case of questions.

By the way, here's where I got the clue.