ENH: pressurePIDControlInletVelocity: new BC to match velocity to user-provided pressure drop

- user provides two planes and pressure drop across these
- bc assume potential flow and works out inlet velocity that would cause
an equivalent pressure drop

src/finiteVolume/Make/files

@@ -168,6 +168,7 @@ $(derivedFvPatchFields)/pressureInletOutletVelocity/pressureInletOutletVelocityF
 $(derivedFvPatchFields)/pressureInletUniformVelocity/pressureInletUniformVelocityFvPatchVectorField.C
 $(derivedFvPatchFields)/pressureInletVelocity/pressureInletVelocityFvPatchVectorField.C
 $(derivedFvPatchFields)/pressureNormalInletOutletVelocity/pressureNormalInletOutletVelocityFvPatchVectorField.C
+$(derivedFvPatchFields)/pressurePIDControlInletVelocity/pressurePIDControlInletVelocityFvPatchVectorField.C
 $(derivedFvPatchFields)/fixedNormalInletOutletVelocity/fixedNormalInletOutletVelocityFvPatchVectorField.C
 $(derivedFvPatchFields)/rotatingPressureInletOutletVelocity/rotatingPressureInletOutletVelocityFvPatchVectorField.C
 $(derivedFvPatchFields)/rotatingTotalPressure/rotatingTotalPressureFvPatchScalarField.C

src/finiteVolume/fields/fvPatchFields/derived/pressurePIDControlInletVelocity/pressurePIDControlInletVelocityFvPatchVectorField.C

@@ -0,0 +1,438 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2015 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "pressurePIDControlInletVelocityFvPatchVectorField.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+#include "fvPatchFieldMapper.H"
+#include "surfaceFields.H"
+#include "linear.H"
+#include "steadyStateDdtScheme.H"
+
+// * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
+
+const Foam::surfaceScalarField&
+Foam::pressurePIDControlInletVelocityFvPatchVectorField::facePressure() const
+{
+    const volScalarField& p(db().lookupObject<volScalarField>(pName_));
+
+    const word pfName(pName_ + "f");
+
+    if (!db().foundObject<surfaceScalarField>(pfName))
+    {
+        surfaceScalarField* pfPtr
+        (
+            new surfaceScalarField(pfName, linearInterpolate(p))
+        );
+
+        pfPtr->store();
+    }
+
+    surfaceScalarField& pf
+    (
+        const_cast<surfaceScalarField&>
+        (
+            db().lookupObject<surfaceScalarField>(pfName)
+        )
+    );
+
+    if (!pf.upToDate(p))
+    {
+        pf = linearInterpolate(p);
+    }
+
+    return pf;
+}
+
+
+template <class Type>
+void Foam::pressurePIDControlInletVelocityFvPatchVectorField::faceZoneAverage
+(
+    const word& name,
+    const GeometricField<Type, fvsPatchField, surfaceMesh>& field,
+    scalar& area,
+    Type& average
+) const
+{
+    const fvMesh& mesh(patch().boundaryMesh().mesh());
+
+    const faceZone& zone = mesh.faceZones()[name];
+
+    area = 0;
+    average = pTraits<Type>::zero;
+
+    forAll(zone, faceI)
+    {
+        const label f(zone[faceI]);
+
+        const scalar da(mesh.magSf()[f]);
+
+        area += da;
+        average += da*field[f];
+    }
+
+    reduce(area, sumOp<scalar>());
+    reduce(average, sumOp<Type>());
+
+    average /= area;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::pressurePIDControlInletVelocityFvPatchVectorField::
+pressurePIDControlInletVelocityFvPatchVectorField
+(
+    const fvPatch& p,
+    const DimensionedField<vector, volMesh>& iF
+)
+:
+    fixedValueFvPatchField<vector>(p, iF),
+    upstreamName_(word::null),
+    downstreamName_(word::null),
+    deltaP_(1),
+    shapeFactor_(0),
+    pName_("p"),
+    phiName_("phi"),
+    rhoName_("none"),
+    P_(0),
+    I_(0),
+    D_(0),
+    Q_(- gSum(*this & patch().Sf())),
+    error_(0),
+    errorIntegral_(0),
+    oldQ_(0),
+    oldError_(0),
+    oldErrorIntegral_(0),
+    timeIndex_(db().time().timeIndex())
+{}
+
+
+Foam::pressurePIDControlInletVelocityFvPatchVectorField::
+pressurePIDControlInletVelocityFvPatchVectorField
+(
+    const pressurePIDControlInletVelocityFvPatchVectorField& ptf,
+    const fvPatch& p,
+    const DimensionedField<vector, volMesh>& iF,
+    const fvPatchFieldMapper& mapper
+)
+:
+    fixedValueFvPatchField<vector>(ptf, p, iF, mapper),
+    upstreamName_(ptf.upstreamName_),
+    downstreamName_(ptf.downstreamName_),
+    deltaP_(ptf.deltaP_),
+    shapeFactor_(ptf.shapeFactor_),
+    pName_(ptf.pName_),
+    phiName_(ptf.phiName_),
+    rhoName_(ptf.rhoName_),
+    P_(ptf.P_),
+    I_(ptf.I_),
+    D_(ptf.D_),
+    Q_(ptf.Q_),
+    error_(ptf.error_),
+    errorIntegral_(ptf.errorIntegral_),
+    oldQ_(ptf.oldQ_),
+    oldError_(ptf.oldError_),
+    oldErrorIntegral_(ptf.oldErrorIntegral_),
+    timeIndex_(ptf.timeIndex_)
+{}
+
+
+Foam::pressurePIDControlInletVelocityFvPatchVectorField::
+pressurePIDControlInletVelocityFvPatchVectorField
+(
+    const fvPatch& p,
+    const DimensionedField<vector, volMesh>& iF,
+    const dictionary& dict
+)
+:
+    fixedValueFvPatchField<vector>(p, iF, dict),
+    upstreamName_(dict.lookup("upstream")),
+    downstreamName_(dict.lookup("downstream")),
+    deltaP_(readScalar(dict.lookup("deltaP"))),
+    shapeFactor_(dict.lookupOrDefault<scalar>("shapeFactor", 0)),
+    pName_(dict.lookupOrDefault<word>("p", "p")),
+    phiName_(dict.lookupOrDefault<word>("phi", "phi")),
+    rhoName_(dict.lookupOrDefault<word>("rho", "none")),
+    P_(readScalar(dict.lookup("P"))),
+    I_(readScalar(dict.lookup("I"))),
+    D_(readScalar(dict.lookup("D"))),
+    Q_(- gSum(*this & patch().Sf())),
+    error_(dict.lookupOrDefault<scalar>("error", 0)),
+    errorIntegral_(dict.lookupOrDefault<scalar>("errorIntegral", 0)),
+    oldQ_(0),
+    oldError_(0),
+    oldErrorIntegral_(0),
+    timeIndex_(db().time().timeIndex())
+{}
+
+
+Foam::pressurePIDControlInletVelocityFvPatchVectorField::
+pressurePIDControlInletVelocityFvPatchVectorField
+(
+    const pressurePIDControlInletVelocityFvPatchVectorField& ptf
+)
+:
+    fixedValueFvPatchField<vector>(ptf),
+    upstreamName_(ptf.upstreamName_),
+    downstreamName_(ptf.downstreamName_),
+    deltaP_(ptf.deltaP_),
+    shapeFactor_(ptf.shapeFactor_),
+    pName_(ptf.pName_),
+    phiName_(ptf.phiName_),
+    rhoName_(ptf.rhoName_),
+    P_(ptf.P_),
+    I_(ptf.I_),
+    D_(ptf.D_),
+    Q_(ptf.Q_),
+    error_(ptf.error_),
+    errorIntegral_(ptf.errorIntegral_),
+    oldQ_(ptf.oldQ_),
+    oldError_(ptf.oldError_),
+    oldErrorIntegral_(ptf.oldErrorIntegral_),
+    timeIndex_(ptf.timeIndex_)
+{}
+
+
+Foam::pressurePIDControlInletVelocityFvPatchVectorField::
+pressurePIDControlInletVelocityFvPatchVectorField
+(
+    const pressurePIDControlInletVelocityFvPatchVectorField& ptf,
+    const DimensionedField<vector, volMesh>& iF
+)
+:
+    fixedValueFvPatchField<vector>(ptf, iF),
+    upstreamName_(ptf.upstreamName_),
+    downstreamName_(ptf.downstreamName_),
+    deltaP_(ptf.deltaP_),
+    shapeFactor_(ptf.shapeFactor_),
+    pName_(ptf.pName_),
+    phiName_(ptf.phiName_),
+    rhoName_(ptf.rhoName_),
+    P_(ptf.P_),
+    I_(ptf.I_),
+    D_(ptf.D_),
+    Q_(ptf.Q_),
+    error_(ptf.error_),
+    errorIntegral_(ptf.errorIntegral_),
+    oldQ_(ptf.oldQ_),
+    oldError_(ptf.oldError_),
+    oldErrorIntegral_(ptf.oldErrorIntegral_),
+    timeIndex_(ptf.timeIndex_)
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::pressurePIDControlInletVelocityFvPatchVectorField::updateCoeffs()
+{
+    if (updated())
+    {
+        return;
+    }
+
+    // Get the mesh
+    const fvMesh& mesh(patch().boundaryMesh().mesh());
+
+    // Get the time step
+    const scalar deltaT(db().time().deltaTValue());
+
+    // Get the flux field
+    const surfaceScalarField& phi
+    (
+        db().lookupObject<surfaceScalarField>(phiName_)
+    );
+
+    // Update the old-time quantities
+    if (timeIndex_ != db().time().timeIndex())
+    {
+        timeIndex_ = db().time().timeIndex();
+        oldQ_ = Q_;
+        oldError_ = error_;
+        oldErrorIntegral_ = errorIntegral_;
+    }
+
+    // Get the density
+    scalar rho = 1;
+    if (phi.dimensions() == dimVelocity*dimArea)
+    {
+        // do nothing ...
+    }
+    else if (phi.dimensions() == dimDensity*dimVelocity*dimArea)
+    {
+        const fvPatchField<scalar>& rhoField =
+            patch().lookupPatchField<volScalarField, scalar>(rhoName_);
+
+        rho = gSum(rhoField*patch().magSf())/gSum(patch().magSf());
+    }
+    else
+    {
+        FatalErrorIn
+        (
+            "void Foam::"
+            "pressurePIDControlInletVelocityFvPatchVectorField::"
+            "updateCoeffs()"
+        )   << "The dimensions of the field " << phiName_
+            << "are not recognised. The dimensions are " << phi.dimensions()
+            << ". The dimensions should be either " << dimVelocity*dimArea
+            << " for an incompressible case, or "
+            << dimDensity*dimVelocity*dimArea << " for a compressible case."
+            << exit(FatalError);
+    }
+
+    // Patch properties
+    const scalar patchA = gSum(patch().magSf());
+    Q_ = - gSum(*this & patch().Sf());
+
+    // Face-zone properties (a is upstream, b is downstream)
+    scalar Aa, Ab;
+    vector xa, xb;
+    faceZoneAverage(upstreamName_, mesh.Cf(), Aa, xa);
+    faceZoneAverage(downstreamName_, mesh.Cf(), Ab, xb);
+    const scalar L = mag(xa - xb);
+    const scalar LbyALinear = L/(Aa - Ab)*log(Aa/Ab);
+    const scalar LbyAStep = L/2*(1/Aa + 1/Ab);
+    const scalar LbyA = (1 - shapeFactor_)*LbyALinear + shapeFactor_*LbyAStep;
+
+    // Initialise the pressure drop. If the pressure field does not exist, the
+    // pressure drop is assumed to be that specified. This removes the error,
+    // so there is no control and the analytic inlet velocity is applied. This
+    // scenario only ever going to be applicable to potentialFoam.
+    scalar deltaP = deltaP_;
+    if (db().foundObject<volScalarField>(pName_))
+    {
+        scalar pa, pb;
+        faceZoneAverage(upstreamName_, facePressure(), Aa, pa);
+        faceZoneAverage(downstreamName_, facePressure(), Ab, pb);
+        deltaP = pa - pb;
+    }
+    else
+    {
+        WarningIn
+        (
+            "void Foam::pressurePIDControlInletVelocityFvPatchVectorField::"
+            "updateCoeffs()"
+        )   << "The pressure field name, \"pName\", is \"" << pName_ << "\", "
+            << "but a field of that name was not found. The inlet velocity "
+            << "will be set to an analytical value calculated from the "
+            << "specified pressure drop. No PID control will be done and "
+            << "transient effects will be ignored. This behaviour is designed "
+            << "to be appropriate for potentialFoam solutions. If you are "
+            << "getting this warning from another solver, you have probably "
+            << "specified an incorrect pressure name."
+            << endl << endl;
+    }
+
+    // Target and measured flow rates
+    scalar QTarget, QMeasured;
+    const scalar a = (1/sqr(Ab) - 1/sqr(Aa))/(2*rho);
+    if (!mesh.steady() && db().foundObject<volScalarField>(pName_))
+    {
+        const scalar b = LbyA/deltaT;
+        const scalar c = - LbyA/deltaT*oldQ_ /* - deltaP */;
+        QTarget = (- b + sqrt(sqr(b) - 4*a*(c - deltaP_)))/(2*a);
+        QMeasured = (- b + sqrt(sqr(b) - 4*a*(c - deltaP)))/(2*a);
+    }
+    else
+    {
+        QTarget = sqrt(deltaP_/a);
+        QMeasured = sqrt(deltaP/a);
+    }
+
+    // Errors
+    error_ = QTarget - QMeasured;
+    errorIntegral_ = oldErrorIntegral_ + 0.5*(error_ + oldError_);
+    const scalar errorDifferential = oldError_ - error_;
+
+    // Update the field
+    operator==
+    (
+      - patch().nf()
+       *(
+            QTarget
+          + P_*error_
+          + I_*errorIntegral_
+          + D_*errorDifferential
+        )/patchA
+    );
+
+    // Log output
+    if (debug)
+    {
+        const dimensionSet pDimensions(phi.dimensions()*dimVelocity/dimArea);
+        const scalar error = deltaP/deltaP_ - 1;
+        const scalar newQ = - gSum(*this & patch().Sf());
+        Info<< "pressurePIDControlInletVelocityFvPatchField " << patch().name()
+            << endl << "         "
+            << dimensionedScalar("U", dimVelocity, newQ/patchA)
+            << endl << "    "
+            << dimensionedScalar("deltaP", pDimensions, deltaP)
+            << " (" << mag(error)*100 << "\% "
+            << (error < 0 ? "below" : "above") << " the target)" << endl;
+    }
+
+    fixedValueFvPatchField<vector>::updateCoeffs();
+}
+
+
+void Foam::pressurePIDControlInletVelocityFvPatchVectorField::write
+(
+    Ostream& os
+) const
+{
+    fvPatchField<vector>::write(os);
+
+    os.writeKeyword("deltaP") << deltaP_ << token::END_STATEMENT << nl;
+    os.writeKeyword("upstream") << upstreamName_ << token::END_STATEMENT << nl;
+    os.writeKeyword("downstream")
+        << downstreamName_ << token::END_STATEMENT << nl;
+    os.writeKeyword("shapeFactor") << shapeFactor_
+        << token::END_STATEMENT << nl;
+    writeEntryIfDifferent<word>(os, "p", "p", pName_);
+    writeEntryIfDifferent<word>(os, "rho", "none", rhoName_);
+    os.writeKeyword("P") << P_ << token::END_STATEMENT << nl;
+    os.writeKeyword("I") << I_ << token::END_STATEMENT << nl;
+    os.writeKeyword("D") << D_ << token::END_STATEMENT << nl;
+    os.writeKeyword("error") << error_ << token::END_STATEMENT << nl;
+    os.writeKeyword("errorIntegral")
+        << errorIntegral_ << token::END_STATEMENT << nl;
+
+    writeEntry("value", os);
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+   makePatchTypeField
+   (
+       fvPatchVectorField,
+       pressurePIDControlInletVelocityFvPatchVectorField
+   );
+}
+
+
+// ************************************************************************* //

src/finiteVolume/fields/fvPatchFields/derived/pressurePIDControlInletVelocity/pressurePIDControlInletVelocityFvPatchVectorField.H

@@ -0,0 +1,279 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2015 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::pressurePIDControlInletVelocityFvPatchVectorField
+
+Group
+    grpInletBoundaryConditions
+
+Description
+    This boundary condition tries to generate an inlet velocity that maintains
+    a specified pressure drop between two face zones downstream. The zones
+    should fully span a duct through which all the inlet flow passes.
+
+    An incompressible, lossless analysis of the flow between the inlet and the
+    two face-zones is performed. An ideal inlet velocity is thereby calculated
+    from the user-specified pressure drop. This analysis can include the
+    transient effect of the inlet velocity change. In this case, a shape factor
+    is included to represent non-linearity in the duct cross section.
+
+    The average pressure drop between the two face zones is measured. The same
+    incompressible, lossless analysis is performed using this pressure drop.
+    The difference between the two computed velocities is considered as an
+    error. The ideal inlet is modified so as to drive this error to zero. This
+    is accomplished by means of a PID control algorithm, for which
+    non-dimensional gains are specified by the user.
+
+    The shape factor takes a value of 0 for a linear change in cross sectional
+    area between the two face zones. A value of 1 represents a step change in
+    area at the mid-point between the zones. A smooth cubic or cosine profile
+    between two zones with zero divergence is typically represented by a factor
+    of between 0.2 and 0.25.
+
+    \heading Patch usage
+
+    \table
+        Property    | Description                 | Required | Default value
+        upstream    | upstream face zone name     | yes      |
+        downstream  | downstream face zone name   | yes      |
+        deltaP      | desired pressure drop       | yes      |
+        shapeFactor | non-linearity in the nozzle | no       | 0
+        p           | pressure field name         | no       | p
+        phi         | flux field name             | yes      | phi
+        rho         | density field name          | no       | none
+        P           | proportional gain           | yes      |
+        I           | integral gain               | yes      |
+        D           | differential gain           | yes      |
+    \endtable
+
+    Example of the boundary condition specification:
+
+    \verbatim
+    myPatch
+    {
+        type            pressurePIDControlInletVelocity;
+        upstream        upstream;
+        downstream      downstream;
+        deltaP          200;
+        shapeFactor     0;
+        p               p;
+        phi             phi;
+        rho             none;
+        P               0.5;
+        I               0.5;
+        D               0.1;
+        value           uniform (0 0 0);
+    }
+
+SeeAlso
+    Foam::fixedValueFvPatchField
+
+SourceFiles
+    pressurePIDControlInletVelocityFvPatchVectorField.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef pressurePIDControlInletVelocityFvPatchVectorField_H
+#define pressurePIDControlInletVelocityFvPatchVectorField_H
+
+#include "fixedValueFvPatchFields.H"
+#include "Switch.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+/*---------------------------------------------------------------------------*\
+     Class pressurePIDControlInletVelocityFvPatchVectorField Declaration
+\*---------------------------------------------------------------------------*/
+
+class pressurePIDControlInletVelocityFvPatchVectorField
+:
+    public fixedValueFvPatchVectorField
+{
+    // Private data
+
+        //- Name of the upstream face zone
+        const word upstreamName_;
+
+        //- Name of the downstream face zone
+        const word downstreamName_;
+
+        //- Desired pressure difference between upstream and downstream
+        const scalar deltaP_;
+
+        //- Nozzle shape factor
+        const scalar shapeFactor_;
+
+        //- Name of the pressure field
+        const word pName_;
+
+        //- Name of the flux field
+        const word phiName_;
+
+        //- Name of the density field (if any)
+        const word rhoName_;
+
+        //- Proportional gain
+        const scalar P_;
+
+        //- Integral gain
+        const scalar I_;
+
+        //- Derivative gain
+        const scalar D_;
+
+        //- Volumetric flow rate
+        scalar Q_;
+
+        //- Error
+        scalar error_;
+
+        //- Error integral w.r.t. time
+        scalar errorIntegral_;
+
+        //- Old volumetric flow rate
+        scalar oldQ_;
+
+        //- Old error
+        scalar oldError_;
+
+        //- Old error integral w.r.t. time
+        scalar oldErrorIntegral_;
+
+        //- Time index of the last update
+        label timeIndex_;
+
+
+    // Private member functions
+
+        //- Return the pressure interpolated to the faces
+        const surfaceScalarField& facePressure() const;
+
+        //- Calculate the average on a face zone
+        template <class Type>
+        void faceZoneAverage
+        (
+            const word& name,
+            const GeometricField<Type, fvsPatchField, surfaceMesh>& field,
+            scalar& area,
+            Type& average
+        ) const;
+
+
+public:
+
+   //- Runtime type information
+   TypeName("pressurePIDControlInletVelocity");
+
+
+   // Constructors
+
+        //- Construct from patch and internal field
+        pressurePIDControlInletVelocityFvPatchVectorField
+        (
+            const fvPatch&,
+            const DimensionedField<vector, volMesh>&
+        );
+
+        //- Construct from patch, internal field and dictionary
+        pressurePIDControlInletVelocityFvPatchVectorField
+        (
+            const fvPatch&,
+            const DimensionedField<vector, volMesh>&,
+            const dictionary&
+        );
+
+        //- Construct by mapping given
+        //  flowRateInletVelocityFvPatchVectorField
+        //  onto a new patch
+        pressurePIDControlInletVelocityFvPatchVectorField
+        (
+            const pressurePIDControlInletVelocityFvPatchVectorField&,
+            const fvPatch&,
+            const DimensionedField<vector, volMesh>&,
+            const fvPatchFieldMapper&
+        );
+
+        //- Construct as copy
+        pressurePIDControlInletVelocityFvPatchVectorField
+        (
+            const pressurePIDControlInletVelocityFvPatchVectorField&
+        );
+
+        //- Construct and return a clone
+        virtual tmp<fvPatchVectorField> clone() const
+        {
+            return tmp<fvPatchVectorField>
+            (
+                new pressurePIDControlInletVelocityFvPatchVectorField
+                (
+                    *this
+                )
+            );
+        }
+
+        //- Construct as copy setting internal field reference
+        pressurePIDControlInletVelocityFvPatchVectorField
+        (
+            const pressurePIDControlInletVelocityFvPatchVectorField&,
+            const DimensionedField<vector, volMesh>&
+        );
+
+        //- Construct and return a clone setting internal field reference
+        virtual tmp<fvPatchVectorField> clone
+        (
+            const DimensionedField<vector, volMesh>& iF
+        ) const
+        {
+            return tmp<fvPatchVectorField>
+            (
+                new pressurePIDControlInletVelocityFvPatchVectorField
+                (
+                    *this,
+                    iF
+                )
+            );
+        }
+
+
+    // Member functions
+
+        //- Update the coefficients associated with the patch field
+        virtual void updateCoeffs();
+
+        //- Write
+        virtual void write(Ostream&) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //