diff --git a/src/finiteVolume/Make/files b/src/finiteVolume/Make/files
index 8f83ea99b95550838f6561e848c7319f932b31bd..d13d0124687f353e9987288d01d812a726195e9b 100644
--- a/src/finiteVolume/Make/files
+++ b/src/finiteVolume/Make/files
@@ -371,6 +371,7 @@ $(porosity)/porosityModel/porosityModelList.C
$(porosity)/porosityModel/IOporosityModelList.C
$(porosity)/DarcyForchheimer/DarcyForchheimer.C
$(porosity)/powerLaw/powerLaw.C
+$(porosity)/fixedCoeff/fixedCoeff.C
MRF = $(general)/MRF
$(MRF)/MRFZone.C
diff --git a/src/finiteVolume/cfdTools/general/porosityModel/fixedCoeff/fixedCoeff.C b/src/finiteVolume/cfdTools/general/porosityModel/fixedCoeff/fixedCoeff.C
new file mode 100644
index 0000000000000000000000000000000000000000..55c4202d5a27c5466ce68593f4da8980cda39ae3
--- /dev/null
+++ b/src/finiteVolume/cfdTools/general/porosityModel/fixedCoeff/fixedCoeff.C
@@ -0,0 +1,243 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2012 OpenFOAM Foundation
+ \\/ 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 "addToRunTimeSelectionTable.H"
+#include "fixedCoeff.H"
+#include "fvMatrices.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+ namespace porosityModels
+ {
+ defineTypeNameAndDebug(fixedCoeff, 0);
+ addToRunTimeSelectionTable(porosityModel, fixedCoeff, mesh);
+ }
+}
+
+
+// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
+
+void Foam::porosityModels::fixedCoeff::apply
+(
+ scalarField& Udiag,
+ vectorField& Usource,
+ const scalarField& V,
+ const vectorField& U,
+ const scalar rho
+) const
+{
+ const tensor& alpha = alpha_.value();
+ const tensor& beta = beta_.value();
+
+ forAll(cellZoneIds_, zoneI)
+ {
+ const labelList& cells = mesh_.cellZones()[cellZoneIds_[zoneI]];
+
+ forAll(cells, i)
+ {
+ const label cellI = cells[i];
+
+ const tensor Cd = rho*(alpha + beta*mag(U[cellI]));
+
+ const scalar isoCd = tr(Cd);
+
+ Udiag[cellI] += V[cellI]*isoCd;
+ Usource[cellI] -= V[cellI]*((Cd - I*isoCd) & U[cellI]);
+ }
+ }
+}
+
+
+void Foam::porosityModels::fixedCoeff::apply
+(
+ tensorField& AU,
+ const vectorField& U,
+ const scalar rho
+) const
+{
+ const tensor& alpha = alpha_.value();
+ const tensor& beta = beta_.value();
+
+ forAll(cellZoneIds_, zoneI)
+ {
+ const labelList& cells = mesh_.cellZones()[cellZoneIds_[zoneI]];
+
+ forAll(cells, i)
+ {
+ const label cellI = cells[i];
+ AU[cellI] += rho*(alpha + beta*mag(U[cellI]));
+ }
+ }
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
+
+Foam::porosityModels::fixedCoeff::fixedCoeff
+(
+ const word& name,
+ const word& modelType,
+ const fvMesh& mesh,
+ const dictionary& dict
+)
+:
+ porosityModel(name, modelType, mesh, dict),
+ coordSys_(coeffs_, mesh),
+ alpha_("alpha", dimless/dimTime, tensor::zero),
+ beta_("beta", dimless/dimLength, tensor::zero)
+{
+ // local-to-global transformation tensor
+ const tensor& E = coordSys_.R();
+
+ dimensionedVector alpha(coeffs_.lookup("alpha"));
+ if (alpha_.dimensions() != alpha.dimensions())
+ {
+ FatalIOErrorIn
+ (
+ "Foam::porosityModels::fixedCoeff::fixedCoeff"
+ "("
+ "const word&, "
+ "const word&, "
+ "const fvMesh&, "
+ "const dictionary&"
+ ")",
+ coeffs_
+ ) << "incorrect dimensions for alpha: " << alpha.dimensions()
+ << " should be " << alpha_.dimensions()
+ << exit(FatalIOError);
+ }
+
+ adjustNegativeResistance(alpha);
+
+ alpha_.value().xx() = alpha.value().x();
+ alpha_.value().yy() = alpha.value().y();
+ alpha_.value().zz() = alpha.value().z();
+ alpha_.value() = (E & alpha_ & E.T()).value();
+
+ dimensionedVector beta(coeffs_.lookup("beta"));
+ if (beta_.dimensions() != beta.dimensions())
+ {
+ FatalIOErrorIn
+ (
+ "Foam::porosityModels::fixedCoeff::fixedCoeff"
+ "("
+ "const word&, "
+ "const word&, "
+ "const fvMesh&, "
+ "const dictionary&"
+ ")",
+ coeffs_
+ ) << "incorrect dimensions for beta: " << beta.dimensions()
+ << " should be " << beta_.dimensions()
+ << exit(FatalIOError);
+ }
+
+ adjustNegativeResistance(beta);
+
+ beta_.value().xx() = beta.value().x();
+ beta_.value().yy() = beta.value().y();
+ beta_.value().zz() = beta.value().z();
+ beta_.value() = (E & beta_ & E.T()).value();
+}
+
+
+// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
+
+Foam::porosityModels::fixedCoeff::~fixedCoeff()
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
+
+void Foam::porosityModels::fixedCoeff::correct
+(
+ fvVectorMatrix& UEqn
+) const
+{
+ const vectorField& U = UEqn.psi();
+ const scalarField& V = mesh_.V();
+ scalarField& Udiag = UEqn.diag();
+ vectorField& Usource = UEqn.source();
+
+ scalar rho = 1.0;
+ if (UEqn.dimensions() == dimForce)
+ {
+ coeffs_.lookup("rhoRef") >> rho;
+ }
+
+ apply(Udiag, Usource, V, U, rho);
+}
+
+
+void Foam::porosityModels::fixedCoeff::correct
+(
+ fvVectorMatrix& UEqn,
+ const volScalarField&,
+ const volScalarField&
+) const
+{
+ const vectorField& U = UEqn.psi();
+ const scalarField& V = mesh_.V();
+ scalarField& Udiag = UEqn.diag();
+ vectorField& Usource = UEqn.source();
+
+ scalar rho = 1.0;
+ if (UEqn.dimensions() == dimForce)
+ {
+ coeffs_.lookup("rhoRef") >> rho;
+ }
+
+ apply(Udiag, Usource, V, U, rho);
+}
+
+
+void Foam::porosityModels::fixedCoeff::correct
+(
+ const fvVectorMatrix& UEqn,
+ volTensorField& AU
+) const
+{
+ const vectorField& U = UEqn.psi();
+
+ scalar rho = 1.0;
+ if (UEqn.dimensions() == dimForce)
+ {
+ coeffs_.lookup("rhoRef") >> rho;
+ }
+
+ apply(AU, U, rho);
+}
+
+
+void Foam::porosityModels::fixedCoeff::writeData(Ostream& os) const
+{
+ os << indent << name_ << endl;
+ dict_.write(os);
+}
+
+
+// ************************************************************************* //
diff --git a/src/finiteVolume/cfdTools/general/porosityModel/fixedCoeff/fixedCoeff.H b/src/finiteVolume/cfdTools/general/porosityModel/fixedCoeff/fixedCoeff.H
new file mode 100644
index 0000000000000000000000000000000000000000..c0e28ac87e31bec4a4ac20085b6562e2ae6e701d
--- /dev/null
+++ b/src/finiteVolume/cfdTools/general/porosityModel/fixedCoeff/fixedCoeff.H
@@ -0,0 +1,159 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2012 OpenFOAM Foundation
+ \\/ 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::fixedCoeff
+
+Description
+ Fixed coefficient form of porosity model
+
+ \f[
+ S = - \rho_ref (\alpha + \beta |U|) U
+ \f]
+
+ In the case of compressible flow, a value for the reference density is
+ required
+
+SourceFiles
+ fixedCoeff.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fixedCoeff_H
+#define fixedCoeff_H
+
+#include "porosityModel.H"
+#include "coordinateSystem.H"
+#include "dimensionedTensor.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace porosityModels
+{
+
+/*---------------------------------------------------------------------------*\
+ Class fixedCoeff Declaration
+\*---------------------------------------------------------------------------*/
+
+class fixedCoeff
+:
+ public porosityModel
+{
+private:
+
+ // Private data
+
+ //- Local co-ordinate system
+ coordinateSystem coordSys_;
+
+ //- Model alpha coefficient [1/s]
+ dimensionedTensor alpha_;
+
+ //- Model beta coefficient [1/m]
+ dimensionedTensor beta_;
+
+
+ // Private Member Functions
+
+ //- Apply
+ void apply
+ (
+ scalarField& Udiag,
+ vectorField& Usource,
+ const scalarField& V,
+ const vectorField& U,
+ const scalar rho
+ ) const;
+
+ //- Apply
+ void apply
+ (
+ tensorField& AU,
+ const vectorField& U,
+ const scalar rho
+ ) const;
+
+ //- Disallow default bitwise copy construct
+ fixedCoeff(const fixedCoeff&);
+
+ //- Disallow default bitwise assignment
+ void operator=(const fixedCoeff&);
+
+
+public:
+
+ //- Runtime type information
+ TypeName("fixedCoeff");
+
+ //- Constructor
+ fixedCoeff
+ (
+ const word& name,
+ const word& modelType,
+ const fvMesh& mesh,
+ const dictionary& dict
+ );
+
+ //- Destructor
+ virtual ~fixedCoeff();
+
+
+ // Member Functions
+
+ //- Add resistance
+ virtual void correct(fvVectorMatrix& UEqn) const;
+
+ //- Add resistance
+ virtual void correct
+ (
+ fvVectorMatrix& UEqn,
+ const volScalarField& rho,
+ const volScalarField& mu
+ ) const;
+
+ //- Add resistance
+ virtual void correct
+ (
+ const fvVectorMatrix& UEqn,
+ volTensorField& AU
+ ) const;
+
+
+ // I-O
+
+ //- Write
+ void writeData(Ostream& os) const;
+};
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace porosityModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //