[fredo490]

Hello everybody,
I would like to create a new boundary condition derived from the outletInlet. I want a "zeroGradient" as outlet and a "slip" / "symmetry" as inlet. But before coding this, I went to study the source code of inletOutlet and outletInlet.

I know that depending of the sign of "phi" (flux on the patch field), the code switch from one or the other boundary. However, I cannot understand the piece of code in charge of this process.

For the inletOutlet:
(opt/openfoam220/src/finiteVolume/fields/fvPatchFields/derived/inletOutlet/inletOutletFvPatchField.C)

template<class Type>
Foam::inletOutletFvPatchField<Type>::inletOutletFvPatchField
(
    const fvPatch& p,
    const DimensionedField<Type, volMesh>& iF,
    const dictionary& dict
)
:
    mixedFvPatchField<Type>(p, iF),
    phiName_(dict.lookupOrDefault<word>("phi", "phi")) // get the flux name
{
    this->refValue() = Field<Type>("inletValue", dict, p.size()); // get the desired fixed value at the inlet

    if (dict.found("value")) // ??? if the flux go outside the domain ???
    {
        fvPatchField<Type>::operator=
        (
            Field<Type>("value", dict, p.size()) // the patch get the field value 
        );
    }
    else // ??? if the flux go inside the domain ???
    {
        fvPatchField<Type>::operator=(this->refValue()); // the patch get the desired fixed value
    }

    this->refGrad() = pTraits<Type>::zero; // set the zero gradient vector
    this->valueFraction() = 0.0; // ??? for multiphase flow ? ???
}

And for the outletInlet
(opt/openfoam220/src/finiteVolume/fields/fvPatchFields/derived/inletOutlet/inletOutletFvPatchField.C)

template<class Type>
Foam::outletInletFvPatchField<Type>::outletInletFvPatchField
(
    const fvPatch& p,
    const DimensionedField<Type, volMesh>& iF,
    const dictionary& dict
)
:
    mixedFvPatchField<Type>(p, iF),
    phiName_(dict.lookupOrDefault<word>("phi", "phi")) // get the flux name
{
    this->refValue() = Field<Type>("outletValue", dict, p.size()); // get the desired fixed value at the inlet

    if (dict.found("value")) // ??? if the flux go inside the domain ???
    {
        fvPatchField<Type>::operator=
        (
            Field<Type>("value", dict, p.size()) // the patch get the field value 
        );
    }
    else // ??? if the flux go outside the domain ???
    {
        fvPatchField<Type>::operator=(this->refValue()); // the patch get the desired fixed value
    }

    this->refGrad() = pTraits<Type>::zero;  // set the zero gradient vector
    this->valueFraction() = 0.0; // ??? for multiphase flow ? ???
}

My problem is that the same code should do two opposite things:
inletOutlet:

if (dict.found("value")) // ??? if the flux go outside the domain ???

outletInlet:

if (dict.found("value")) // ??? if the flux go inside the domain ???

The only difference I have found is in the member function.
inletOutlet:

template<class Type>
void Foam::inletOutletFvPatchField<Type>::updateCoeffs()
{
    if (this->updated())
    {
        return;
    }

    const Field<scalar>& phip =
        this->patch().template lookupPatchField<surfaceScalarField, scalar>
        (
            phiName_
        );

    this->valueFraction() = 1.0 - pos(phip); // The difference is here

    mixedFvPatchField<Type>::updateCoeffs();
}

outletInlet

template<class Type>
void Foam::outletInletFvPatchField<Type>::updateCoeffs()
{
    if (this->updated())
    {
        return;
    }

    const fvsPatchField<scalar>& phip =
        this->patch().template lookupPatchField<surfaceScalarField, scalar>
        (
            phiName_
        );

    this->valueFraction() = pos(phip); // The difference is here

    mixedFvPatchField<Type>::updateCoeffs();
}

Does anyone know how this code works ? I am a bit lost

[fredo490]

a small up