TurbulenceModels::generalizedNewtonian: New structure to support generalized Newtonian laminar transport

Within this structure the BirdCarreau, Casson, CrossPowerLaw, HerschelBulkley,
powerLaw and strainRateFunction strain-dependent viscosity based non-Newtonian
fluid models may be selected for incompressible or compressible flow.

In the case of compressible flow the strain-dependent viscosity functions are
applied to the temperature dependent viscosity so that if the WLF viscosity
model is chosen in conjunction with the CrossPowerLaw the effective model is
Cross-WLF which is commonly used for polymer flow.

These models are selected in the constant/turbulenceProperties file, e.g.

simulationType  laminar;

laminar
{
    laminarModel generalizedNewtonian;

    viscosityModel CrossPowerLaw;

    nuInf      10;
    m          0.4;
    n          3;
}

This new implementation is more general and flexible than the previous
incompressible only non-Newtonian viscosity models, which were selected in the
constant/transportProperties file.  This implementation is now deprecated and
will be phased-out.

src/TurbulenceModels/compressible/turbulentFluidThermoModels/turbulentFluidThermoModels.C

@@ -45,6 +45,9 @@ makeBaseTurbulenceModel
 #include "Stokes.H"
 makeLaminarModel(Stokes);
 
+#include "generalizedNewtonian.H"
+makeLaminarModel(generalizedNewtonian);
+
 #include "Maxwell.H"
 makeLaminarModel(Maxwell);
 

src/TurbulenceModels/incompressible/turbulentTransportModels/turbulentTransportModels.C

@@ -44,6 +44,9 @@ makeBaseTurbulenceModel
 #include "Stokes.H"
 makeLaminarModel(Stokes);
 
+#include "generalizedNewtonian.H"
+makeLaminarModel(generalizedNewtonian);
+
 #include "Maxwell.H"
 makeLaminarModel(Maxwell);
 

src/TurbulenceModels/turbulenceModels/Make/files

@@ -63,5 +63,14 @@ RASBCs = RAS/derivedFvPatchFields
 $(RASBCs)/turbulentMixingLengthDissipationRateInlet/turbulentMixingLengthDissipationRateInletFvPatchScalarField.C
 $(RASBCs)/turbulentMixingLengthFrequencyInlet/turbulentMixingLengthFrequencyInletFvPatchScalarField.C
 
+generalizedNewtonianViscosityModels = laminar/generalizedNewtonian/generalizedNewtonianViscosityModels
+$(generalizedNewtonianViscosityModels)/generalizedNewtonianViscosityModel/generalizedNewtonianViscosityModel.C
+$(generalizedNewtonianViscosityModels)/generalizedNewtonianViscosityModel/generalizedNewtonianViscosityModelNew.C
+$(generalizedNewtonianViscosityModels)/CrossPowerLaw/CrossPowerLaw.C
+$(generalizedNewtonianViscosityModels)/BirdCarreau/BirdCarreau.C
+$(generalizedNewtonianViscosityModels)/Casson/Casson.C
+$(generalizedNewtonianViscosityModels)/HerschelBulkley/HerschelBulkley.C
+$(generalizedNewtonianViscosityModels)/powerLaw/powerLaw.C
+$(generalizedNewtonianViscosityModels)/strainRateFunction/strainRateFunction.C
 
 LIB = $(FOAM_LIBBIN)/libturbulenceModels

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonian.C

@@ -0,0 +1,264 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "generalizedNewtonian.H"
+#include "volFields.H"
+#include "surfaceFields.H"
+#include "fvcGrad.H"
+#include "fvcDiv.H"
+#include "fvmLaplacian.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+template<class BasicTurbulenceModel>
+generalizedNewtonian<BasicTurbulenceModel>::generalizedNewtonian
+(
+    const alphaField& alpha,
+    const rhoField& rho,
+    const volVectorField& U,
+    const surfaceScalarField& alphaRhoPhi,
+    const surfaceScalarField& phi,
+    const transportModel& transport,
+    const word& propertiesName
+)
+:
+    linearViscousStress<laminarModel<BasicTurbulenceModel>>
+    (
+        typeName,
+        alpha,
+        rho,
+        U,
+        alphaRhoPhi,
+        phi,
+        transport,
+        propertiesName
+    ),
+
+    viscosityModel_
+    (
+        generalizedNewtonianViscosityModel::New
+        (
+            this->coeffDict_
+        )
+    ),
+
+    nu_
+    (
+        IOobject
+        (
+            IOobject::groupName("generalizedNewtonian:nu", alphaRhoPhi.group()),
+            this->runTime_.timeName(),
+            this->mesh_,
+            IOobject::NO_READ,
+            IOobject::AUTO_WRITE
+        ),
+        viscosityModel_->nu(this->nu(), strainRate())
+    )
+{}
+
+
+// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
+
+template<class BasicTurbulenceModel>
+Foam::tmp<Foam::volScalarField>
+generalizedNewtonian<BasicTurbulenceModel>::strainRate() const
+{
+    return sqrt(2.0)*mag(symm(fvc::grad(this->U())));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+template<class BasicTurbulenceModel>
+bool generalizedNewtonian<BasicTurbulenceModel>::read()
+{
+    viscosityModel_->read(this->coeffDict_);
+
+    return true;
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<volScalarField>
+generalizedNewtonian<BasicTurbulenceModel>::nut() const
+{
+    return tmp<volScalarField>
+    (
+        new volScalarField
+        (
+            IOobject
+            (
+                IOobject::groupName("nut", this->alphaRhoPhi_.group()),
+                this->runTime_.timeName(),
+                this->mesh_,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                false
+            ),
+            this->mesh_,
+            dimensionedScalar("nut", dimViscosity, 0.0)
+        )
+    );
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<scalarField>
+generalizedNewtonian<BasicTurbulenceModel>::nut
+(
+    const label patchi
+) const
+{
+    return tmp<scalarField>
+    (
+        new scalarField(this->mesh_.boundary()[patchi].size(), 0.0)
+    );
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<volScalarField>
+generalizedNewtonian<BasicTurbulenceModel>::nuEff() const
+{
+    return tmp<volScalarField>
+    (
+        new volScalarField
+        (
+            IOobject::groupName("nuEff", this->alphaRhoPhi_.group()), nu_
+        )
+    );
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<scalarField>
+generalizedNewtonian<BasicTurbulenceModel>::nuEff
+(
+    const label patchi
+) const
+{
+    return nu_.boundaryField()[patchi];
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<volScalarField>
+generalizedNewtonian<BasicTurbulenceModel>::k() const
+{
+    return tmp<volScalarField>
+    (
+        new volScalarField
+        (
+            IOobject
+            (
+                IOobject::groupName("k", this->alphaRhoPhi_.group()),
+                this->runTime_.timeName(),
+                this->mesh_,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                false
+            ),
+            this->mesh_,
+            dimensionedScalar("k", sqr(this->U_.dimensions()), 0.0)
+        )
+    );
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<volScalarField>
+generalizedNewtonian<BasicTurbulenceModel>::epsilon() const
+{
+    return tmp<volScalarField>
+    (
+        new volScalarField
+        (
+            IOobject
+            (
+                IOobject::groupName("epsilon", this->alphaRhoPhi_.group()),
+                this->runTime_.timeName(),
+                this->mesh_,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                false
+            ),
+            this->mesh_,
+            dimensionedScalar
+            (
+                "epsilon", sqr(this->U_.dimensions())/dimTime, 0.0
+            )
+        )
+    );
+}
+
+
+template<class BasicTurbulenceModel>
+tmp<volSymmTensorField>
+generalizedNewtonian<BasicTurbulenceModel>::R() const
+{
+    return tmp<volSymmTensorField>
+    (
+        new volSymmTensorField
+        (
+            IOobject
+            (
+                IOobject::groupName("R", this->alphaRhoPhi_.group()),
+                this->runTime_.timeName(),
+                this->mesh_,
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                false
+            ),
+            this->mesh_,
+            dimensionedSymmTensor
+            (
+                "R", sqr(this->U_.dimensions()), Zero
+            )
+        )
+    );
+}
+
+
+template<class BasicTurbulenceModel>
+void generalizedNewtonian<BasicTurbulenceModel>::correct()
+{
+    nu_ = viscosityModel_->nu(this->nu(), strainRate());
+    laminarModel<BasicTurbulenceModel>::correct();
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace laminarModels
+} // End namespace Foam
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonian.H

@@ -0,0 +1,172 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonian
+
+Description
+    Turbulence model for shear-dependent Non-Newtonian flow.
+
+SourceFiles
+    generalizedNewtonian.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef generalizedNewtonian_H
+#define generalizedNewtonian_H
+
+#include "laminarModel.H"
+#include "linearViscousStress.H"
+#include "generalizedNewtonianViscosityModel.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+
+/*---------------------------------------------------------------------------*\
+                    Class generalizedNewtonian Declaration
+\*---------------------------------------------------------------------------*/
+
+template<class BasicTurbulenceModel>
+class generalizedNewtonian
+:
+    public linearViscousStress<laminarModel<BasicTurbulenceModel>>
+{
+
+protected:
+
+    // Protected data
+
+        //- Run-time selectable non-Newtonian viscosity model
+        autoPtr<generalizedNewtonianViscosityModel> viscosityModel_;
+
+        //- The non-Newtonian viscosity field
+        volScalarField nu_;
+
+
+    // Protected Member Functions
+
+        virtual tmp<volScalarField> strainRate() const;
+
+
+public:
+
+    typedef typename BasicTurbulenceModel::alphaField alphaField;
+    typedef typename BasicTurbulenceModel::rhoField rhoField;
+    typedef typename BasicTurbulenceModel::transportModel transportModel;
+
+
+    //- Runtime type information
+    TypeName("generalizedNewtonian");
+
+
+    // Constructors
+
+        //- Construct from components
+        generalizedNewtonian
+        (
+            const alphaField& alpha,
+            const rhoField& rho,
+            const volVectorField& U,
+            const surfaceScalarField& alphaRhoPhi,
+            const surfaceScalarField& phi,
+            const transportModel& transport,
+            const word& propertiesName = turbulenceModel::propertiesName
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected turbulence model
+        static autoPtr<generalizedNewtonian> New
+        (
+            const alphaField& alpha,
+            const rhoField& rho,
+            const volVectorField& U,
+            const surfaceScalarField& alphaRhoPhi,
+            const surfaceScalarField& phi,
+            const transportModel& transport,
+            const word& propertiesName = turbulenceModel::propertiesName
+        );
+
+
+    //- Destructor
+    virtual ~generalizedNewtonian()
+    {}
+
+
+    // Member Functions
+
+        //- Read turbulenceProperties dictionary
+        virtual bool read();
+
+        //- Return the turbulence viscosity,
+        //  i.e. 0 for generalized Newtonian flow
+        virtual tmp<volScalarField> nut() const;
+
+        //- Return the turbulence viscosity on patch
+        virtual tmp<scalarField> nut(const label patchi) const;
+
+        //- Return the effective viscosity
+        //  i.e. the generalizedNewtonian viscosity
+        virtual tmp<volScalarField> nuEff() const;
+
+        //- Return the effective viscosity on patch
+        virtual tmp<scalarField> nuEff(const label patchi) const;
+
+        //- Return the turbulence kinetic energy
+        //  i.e. 0 for generalizedNewtonian flow
+        virtual tmp<volScalarField> k() const;
+
+        //- Return the turbulence kinetic energy dissipation rate,
+        //  i.e. 0 for generalizedNewtonian flow
+        virtual tmp<volScalarField> epsilon() const;
+
+        //- Return the Reynolds stress tensor
+        //  i.e. 0 for generalizedNewtonian flow
+        virtual tmp<volSymmTensorField> R() const;
+
+        //- Correct the generalizedNewtonian viscosity
+        virtual void correct();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "generalizedNewtonian.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/BirdCarreau/BirdCarreau.C

@@ -0,0 +1,131 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "BirdCarreau.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+    defineTypeNameAndDebug(BirdCarreau, 0);
+    addToRunTimeSelectionTable
+    (
+        generalizedNewtonianViscosityModel,
+        BirdCarreau,
+        dictionary
+    );
+}
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModels::BirdCarreau::
+BirdCarreau
+(
+    const dictionary& viscosityProperties
+)
+:
+    generalizedNewtonianViscosityModel(viscosityProperties),
+    nuInf_("nuInf", dimViscosity, 0),
+    k_("k", dimTime, 0),
+    tauStar_( "tauStar", dimViscosity/dimTime, 0),
+    n_("n", dimless, 0),
+    a_("a", dimless, 2)
+{
+    read(viscosityProperties);
+}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModels::BirdCarreau::
+read
+(
+    const dictionary& viscosityProperties
+)
+{
+    generalizedNewtonianViscosityModel::read(viscosityProperties);
+
+    const dictionary& coeffs =
+        viscosityProperties.optionalSubDict(typeName + "Coeffs");
+
+    coeffs.lookup("nuInf") >> nuInf_;
+
+    if (coeffs.found("tauStar"))
+    {
+        coeffs.lookup("tauStar") >> tauStar_;
+    }
+    else
+    {
+        coeffs.lookup("k") >> k_;
+    }
+
+    coeffs.lookup("n") >> n_;
+
+    a_ = coeffs.lookupOrDefault
+    (
+        "a",
+        dimensionedScalar("a", dimless, 2)
+    );
+
+    return true;
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::laminarModels::generalizedNewtonianViscosityModels::BirdCarreau::
+nu
+(
+    const volScalarField& nu0,
+    const volScalarField& strainRate
+) const
+{
+    return
+        nuInf_
+      + (nu0 - nuInf_)
+       *pow
+        (
+            scalar(1)
+          + pow
+            (
+                tauStar_.value() > 0
+              ? nu0*strainRate/tauStar_
+              : k_*strainRate,
+                a_
+            ),
+            (n_ - 1.0)/a_
+        );
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/BirdCarreau/BirdCarreau.H

@@ -0,0 +1,140 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonianViscosityModels::BirdCarreau
+
+Description
+    Bird-Carreau generalized Newtonian viscosity model
+
+    The Bird-Carreau-Yasuda form is also supported if the optional \c a
+    coefficient is specified.  \c a defaults to 2 for the Bird-Carreau model.
+
+    The strain rate coefficient can be specified either as the constant \c k or
+    the critical stress level at the transition to shear thinning \c
+    tauStar if \c tauStar is provided:
+
+    Kinematic viscosity [m^2/s]
+
+    \f[
+        \nu = \nu_\infty\,
+            + (\nu_0 - \nu_\infty)\,
+              \left(1 + (k\gamma)^a \right)^{(n - 1)/a}
+    \f]
+
+    or
+
+    \f[
+        \nu = \nu_\infty
+            + (\nu_0 - \nu_\infty)
+              \left(1 + (\frac{\nu_0\gamma}{\tau^*} )^a \right)^{(n - 1)/a}
+    \f]
+
+    Example specification for a polymer:
+    \verbatim
+         viscosityModel BirdCarreau;
+
+         nuInf       0;
+         tauStar     90;
+         n           0.5;
+    \endverbatim
+
+SourceFiles
+    BirdCarreau.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef BirdCarreau_H
+#define BirdCarreau_H
+
+#include "generalizedNewtonianViscosityModel.H"
+#include "dimensionedScalar.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class BirdCarreau Declaration
+\*---------------------------------------------------------------------------*/
+
+class BirdCarreau
+:
+    public generalizedNewtonianViscosityModel
+{
+    // Private data
+
+        dimensionedScalar nuInf_;
+        dimensionedScalar k_;
+        dimensionedScalar tauStar_;
+        dimensionedScalar n_;
+        dimensionedScalar a_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("BirdCarreau");
+
+
+    // Constructors
+
+        //- Construct from components
+        BirdCarreau(const dictionary& viscosityProperties);
+
+
+    //- Destructor
+    virtual ~BirdCarreau()
+    {}
+
+
+    // Member Functions
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties);
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace generalizedNewtonianViscosityModels
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/Casson/Casson.C

@@ -0,0 +1,119 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "Casson.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+    defineTypeNameAndDebug(Casson, 0);
+    addToRunTimeSelectionTable
+    (
+        generalizedNewtonianViscosityModel,
+        Casson,
+        dictionary
+    );
+}
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModels::Casson::Casson
+(
+    const dictionary& viscosityProperties
+)
+:
+    generalizedNewtonianViscosityModel(viscosityProperties),
+    m_("m", dimViscosity, 0),
+    tau0_("tau0", dimViscosity/dimTime, 0),
+    nuMin_("nuMin", dimViscosity, 0),
+    nuMax_("nuMax", dimViscosity, 0)
+{
+    read(viscosityProperties);
+}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModels::Casson::read
+(
+    const dictionary& viscosityProperties
+)
+{
+    generalizedNewtonianViscosityModel::read(viscosityProperties);
+
+    const dictionary& coeffs =
+        viscosityProperties.optionalSubDict(typeName + "Coeffs");
+
+    coeffs.lookup("m") >> m_;
+    coeffs.lookup("tau0") >> tau0_;
+    coeffs.lookup("nuMin_") >> nuMin_;
+    coeffs.lookup("nuMax_") >> nuMax_;
+
+    return true;
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::laminarModels::generalizedNewtonianViscosityModels::Casson::
+nu
+(
+    const volScalarField& nu0,
+    const volScalarField& strainRate
+) const
+{
+    return max
+    (
+        nuMin_,
+        min
+        (
+            nuMax_,
+            sqr
+            (
+                sqrt
+                (
+                    tau0_
+                   /max
+                    (
+                        strainRate,
+                        dimensionedScalar("vSmall", dimless/dimTime, vSmall)
+                    )
+                ) + sqrt(m_)
+            )
+        )
+    );
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/Casson/Casson.H

@@ -0,0 +1,131 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonianViscosityModels::Casson
+
+Description
+    Casson generalized Newtonian viscosity model
+
+    References:
+    \verbatim
+        Casson, N. (1959).
+        Rheology of disperse systems.
+        In Proceedings of a Conference Organized by the
+        British Society of Rheology.
+        Pergamon Press, New York.
+
+        Fournier, R. L. (2011).
+        Basic transport phenomena in biomedical engineering.
+        CRC Press.
+    \endverbatim
+
+    Example specification for blood:
+    \verbatim
+         viscosityModel Casson;
+
+         m       3.934986e-6;
+         tau0    2.9032e-6;
+         nuMax   13.3333e-6;
+         nuMin   3.9047e-6;
+    \endverbatim
+
+SourceFiles
+    Casson.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef Casson_H
+#define Casson_H
+
+#include "generalizedNewtonianViscosityModel.H"
+#include "dimensionedScalar.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+
+
+/*---------------------------------------------------------------------------*\
+                           Class Casson Declaration
+\*---------------------------------------------------------------------------*/
+
+class Casson
+:
+    public generalizedNewtonianViscosityModel
+{
+    // Private data
+
+        dimensionedScalar m_;
+        dimensionedScalar tau0_;
+        dimensionedScalar nuMin_;
+        dimensionedScalar nuMax_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("Casson");
+
+
+    // Constructors
+
+        //- Construct from components
+        Casson(const dictionary& viscosityProperties);
+
+
+    //- Destructor
+    virtual ~Casson()
+    {}
+
+
+    // Member Functions
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties);
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace generalizedNewtonianViscosityModels
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/CrossPowerLaw/CrossPowerLaw.C

@@ -0,0 +1,123 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "CrossPowerLaw.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+    defineTypeNameAndDebug(CrossPowerLaw, 0);
+
+    addToRunTimeSelectionTable
+    (
+        generalizedNewtonianViscosityModel,
+        CrossPowerLaw,
+        dictionary
+    );
+}
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModels::CrossPowerLaw::
+CrossPowerLaw
+(
+    const dictionary& viscosityProperties
+)
+:
+    generalizedNewtonianViscosityModel(viscosityProperties),
+    nuInf_("nuInf", dimViscosity, 0),
+    m_("m", dimTime, 0),
+    tauStar_( "tauStar", dimViscosity/dimTime, 0),
+    n_("n", dimless, 0)
+{
+    read(viscosityProperties);
+}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModels::CrossPowerLaw::
+read
+(
+    const dictionary& viscosityProperties
+)
+{
+    generalizedNewtonianViscosityModel::read(viscosityProperties);
+
+    const dictionary& coeffs =
+        viscosityProperties.optionalSubDict(typeName + "Coeffs");
+
+    coeffs.lookup("nuInf") >> nuInf_;
+
+    if (coeffs.found("tauStar"))
+    {
+        coeffs.lookup("tauStar") >> tauStar_;
+    }
+    else
+    {
+        coeffs.lookup("m") >> m_;
+    }
+
+    coeffs.lookup("n") >> n_;
+
+    return true;
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::laminarModels::generalizedNewtonianViscosityModels::CrossPowerLaw::
+nu
+(
+    const volScalarField& nu0,
+    const volScalarField& strainRate
+) const
+{
+    return
+       nuInf_
+     + (nu0 - nuInf_)
+       /(
+           scalar(1)
+         + pow
+           (
+                tauStar_.value() > 0
+              ? nu0*strainRate/tauStar_
+              : m_*strainRate,
+                n_
+            )
+        );
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/CrossPowerLaw/CrossPowerLaw.H

@@ -0,0 +1,134 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonianViscosityModels::CrossPowerLaw
+
+Description
+    Cross-Power law generalized Newtonian viscosity model
+
+    The strain rate coefficient can be specified either as the constant \c m or
+    the critical stress level at the transition to shear thinning \c
+    tauStar if \c tauStar is provided:
+
+    Kinematic viscosity [m^2/s]
+
+    \f[
+        \nu = \nu_\infty + \frac{(\nu_0 - \nu_\infty)}{1 + (m\gamma)^n}
+    \f]
+
+    or
+
+    \f[
+        \nu = \nu_\infty
+            + \frac{(\nu_0 - \nu_\infty)}
+                   {1 + \left(\frac{\nu_0\gamma}{\tau^*}\right)^n}
+    \f]
+
+    Example specification:
+    \verbatim
+         viscosityModel CrossPowerLaw;
+
+         nuInf      10;
+         m          0.4;
+         n          3;
+    \endverbatim
+
+SourceFiles
+    CrossPowerLaw.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef CrossPowerLaw_H
+#define CrossPowerLaw_H
+
+#include "generalizedNewtonianViscosityModel.H"
+#include "dimensionedScalar.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class CrossPowerLaw Declaration
+\*---------------------------------------------------------------------------*/
+
+class CrossPowerLaw
+:
+    public generalizedNewtonianViscosityModel
+{
+    // Private data
+
+        dimensionedScalar nuInf_;
+        dimensionedScalar m_;
+        dimensionedScalar tauStar_;
+        dimensionedScalar n_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("CrossPowerLaw");
+
+
+    // Constructors
+
+        //- Construct from components
+        CrossPowerLaw(const dictionary& viscosityProperties);
+
+
+    //- Destructor
+    virtual ~CrossPowerLaw()
+    {}
+
+
+    // Member Functions
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties);
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace generalizedNewtonianViscosityModels
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/HerschelBulkley/HerschelBulkley.C

@@ -0,0 +1,116 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "HerschelBulkley.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+    defineTypeNameAndDebug(HerschelBulkley, 0);
+
+    addToRunTimeSelectionTable
+    (
+        generalizedNewtonianViscosityModel,
+        HerschelBulkley,
+        dictionary
+    );
+}
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModels::HerschelBulkley::
+HerschelBulkley
+(
+    const dictionary& viscosityProperties
+)
+:
+    generalizedNewtonianViscosityModel(viscosityProperties),
+    k_("k", dimViscosity, 0),
+    n_("n", dimless, 0),
+    tau0_("tau0", dimViscosity/dimTime, 0)
+{
+    read(viscosityProperties);
+}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModels::
+HerschelBulkley::read
+(
+    const dictionary& viscosityProperties
+)
+{
+    generalizedNewtonianViscosityModel::read(viscosityProperties);
+
+    const dictionary& coeffs =
+        viscosityProperties.optionalSubDict(typeName + "Coeffs");
+
+    coeffs.lookup("k") >> k_;
+    coeffs.lookup("n") >> n_;
+    coeffs.lookup("tau0") >> tau0_;
+
+    return true;
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::laminarModels::generalizedNewtonianViscosityModels::HerschelBulkley::
+nu
+(
+    const volScalarField& nu0,
+    const volScalarField& strainRate
+) const
+{
+    dimensionedScalar tone("tone", dimTime, 1.0);
+    dimensionedScalar rtone("rtone", dimless/dimTime, 1.0);
+
+    return
+    (
+        min
+        (
+            nu0,
+            (tau0_ + k_*rtone*pow(tone*strainRate, n_))
+           /max
+            (
+                strainRate,
+                dimensionedScalar ("vSmall", dimless/dimTime, vSmall)
+            )
+        )
+    );
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/HerschelBulkley/HerschelBulkley.H

@@ -0,0 +1,106 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonianViscosityModels::HerschelBulkley
+
+Description
+    Herschel-Bulkley generalized Newtonian viscosity model
+
+SourceFiles
+    HerschelBulkley.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef HerschelBulkley_H
+#define HerschelBulkley_H
+
+#include "generalizedNewtonianViscosityModel.H"
+#include "dimensionedScalar.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class HerschelBulkley Declaration
+\*---------------------------------------------------------------------------*/
+
+class HerschelBulkley
+:
+    public generalizedNewtonianViscosityModel
+{
+    // Private data
+
+        dimensionedScalar k_;
+        dimensionedScalar n_;
+        dimensionedScalar tau0_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("HerschelBulkley");
+
+
+    // Constructors
+
+        //- Construct from components
+        HerschelBulkley(const dictionary& viscosityProperties);
+
+
+    //- Destructor
+    virtual ~HerschelBulkley()
+    {}
+
+
+    // Member Functions
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties);
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace generalizedNewtonianViscosityModels
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/generalizedNewtonianViscosityModel/generalizedNewtonianViscosityModel.C

@@ -0,0 +1,65 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "generalizedNewtonianViscosityModel.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+    defineTypeNameAndDebug(generalizedNewtonianViscosityModel, 0);
+    defineRunTimeSelectionTable(generalizedNewtonianViscosityModel, dictionary);
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModel::
+generalizedNewtonianViscosityModel
+(
+    const dictionary& viscosityProperties
+)
+:
+    viscosityProperties_(viscosityProperties)
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModel::read
+(
+    const dictionary& viscosityProperties
+)
+{
+    viscosityProperties_ = viscosityProperties;
+
+    return true;
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/generalizedNewtonianViscosityModel/generalizedNewtonianViscosityModel.H

@@ -0,0 +1,155 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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/>.
+
+Namespace
+    Foam::laminarModels::generalizedNewtonianViscosityModels
+
+Description
+    A namespace for various generalized Newtonian viscosity model
+    implementations.
+
+Class
+    Foam::laminarModels::generalizedNewtonianViscosityModel
+
+Description
+    An abstract base class for generalized Newtonian viscosity models.
+
+SourceFiles
+    generalizedNewtonianViscosityModel.C
+    generalizedNewtonianViscosityModelNew.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef generalizedNewtonianViscosityModel_H
+#define generalizedNewtonianViscosityModel_H
+
+#include "dictionary.H"
+#include "volFieldsFwd.H"
+#include "runTimeSelectionTables.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+
+/*---------------------------------------------------------------------------*\
+                Class generalizedNewtonianViscosityModel Declaration
+\*---------------------------------------------------------------------------*/
+
+class generalizedNewtonianViscosityModel
+{
+
+protected:
+
+    // Protected data
+
+        dictionary viscosityProperties_;
+
+
+    // Private Member Functions
+
+        //- Disallow copy construct
+        generalizedNewtonianViscosityModel
+        (
+            const generalizedNewtonianViscosityModel&
+        );
+
+        //- Disallow default bitwise assignment
+        void operator=(const generalizedNewtonianViscosityModel&);
+
+
+public:
+
+    //- Runtime type information
+    TypeName("generalizedNewtonianViscosityModel");
+
+
+    // Declare run-time constructor selection table
+
+        declareRunTimeSelectionTable
+        (
+            autoPtr,
+            generalizedNewtonianViscosityModel,
+            dictionary,
+            (
+                const dictionary& viscosityProperties
+            ),
+            (viscosityProperties)
+        );
+
+
+    // Selectors
+
+        //- Return a reference to the selected viscosity model
+        static autoPtr<generalizedNewtonianViscosityModel> New
+        (
+            const dictionary& viscosityProperties
+        );
+
+
+    // Constructors
+
+        //- Construct from components
+        generalizedNewtonianViscosityModel
+        (
+            const dictionary& viscosityProperties
+        );
+
+
+    //- Destructor
+    virtual ~generalizedNewtonianViscosityModel()
+    {}
+
+
+    // Member Functions
+
+        //- Return the phase transport properties dictionary
+        const dictionary& viscosityProperties() const
+        {
+            return viscosityProperties_;
+        }
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const = 0;
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties) = 0;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/generalizedNewtonianViscosityModel/generalizedNewtonianViscosityModelNew.C

@@ -0,0 +1,63 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "generalizedNewtonianViscosityModel.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+Foam::autoPtr<Foam::laminarModels::generalizedNewtonianViscosityModel>
+Foam::laminarModels::generalizedNewtonianViscosityModel::New
+(
+    const dictionary& viscosityProperties
+)
+{
+    const word modelType
+    (
+        viscosityProperties.lookup("viscosityModel")
+    );
+
+    Info<< "Selecting generalized Newtonian model " << modelType << endl;
+
+    dictionaryConstructorTable::iterator cstrIter =
+        dictionaryConstructorTablePtr_->find(modelType);
+
+    if (cstrIter == dictionaryConstructorTablePtr_->end())
+    {
+        FatalErrorInFunction
+            << "Unknown generalizedNewtonianViscosityModel type "
+            << modelType << nl << nl
+            << "Valid generalizedNewtonianViscosityModels are : " << endl
+            << dictionaryConstructorTablePtr_->sortedToc()
+            << exit(FatalError);
+    }
+
+    return autoPtr<generalizedNewtonianViscosityModel>
+    (
+        cstrIter()(viscosityProperties)
+    );
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/powerLaw/powerLaw.C

@@ -0,0 +1,117 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "powerLaw.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+    defineTypeNameAndDebug(powerLaw, 0);
+
+    addToRunTimeSelectionTable
+    (
+        generalizedNewtonianViscosityModel,
+        powerLaw,
+        dictionary
+    );
+}
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModels::powerLaw::powerLaw
+(
+    const dictionary& viscosityProperties
+)
+:
+    generalizedNewtonianViscosityModel(viscosityProperties),
+    k_("k", dimViscosity, 0),
+    n_("n", dimless, 0),
+    nuMin_("nuMin", dimViscosity, 0),
+    nuMax_("nuMax", dimViscosity, 0)
+{
+    read(viscosityProperties);
+}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModels::powerLaw::read
+(
+    const dictionary& viscosityProperties
+)
+{
+    generalizedNewtonianViscosityModel::read(viscosityProperties);
+
+    const dictionary& coeffs =
+        viscosityProperties.optionalSubDict(typeName + "Coeffs");
+
+    coeffs.lookup("k") >> k_;
+    coeffs.lookup("n") >> n_;
+    coeffs.lookup("nuMin") >> nuMin_;
+    coeffs.lookup("nuMax") >> nuMax_;
+
+    return true;
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::laminarModels::generalizedNewtonianViscosityModels::powerLaw::
+nu
+(
+    const volScalarField& nu0,
+    const volScalarField& strainRate
+) const
+{
+    return max
+    (
+        nuMin_,
+        min
+        (
+            nuMax_,
+            k_*pow
+            (
+                max
+                (
+                    dimensionedScalar("one", dimTime, 1.0)*strainRate,
+                    dimensionedScalar("small", dimless, small)
+                ),
+                n_.value() - scalar(1)
+            )
+        )
+    );
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/powerLaw/powerLaw.H

@@ -0,0 +1,107 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonianViscosityModels::powerLaw
+
+Description
+    Standard power-law generalized Newtonian viscosity model
+
+SourceFiles
+    powerLaw.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef powerLaw_H
+#define powerLaw_H
+
+#include "generalizedNewtonianViscosityModel.H"
+#include "dimensionedScalar.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class powerLaw Declaration
+\*---------------------------------------------------------------------------*/
+
+class powerLaw
+:
+    public generalizedNewtonianViscosityModel
+{
+    // Private data
+
+        dimensionedScalar k_;
+        dimensionedScalar n_;
+        dimensionedScalar nuMin_;
+        dimensionedScalar nuMax_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("powerLaw");
+
+
+    // Constructors
+
+        //- Construct from components
+        powerLaw(const dictionary& viscosityProperties);
+
+
+    //- Destructor
+    virtual ~powerLaw()
+    {}
+
+
+    // Member Functions
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties);
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace generalizedNewtonianViscosityModels
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/strainRateFunction/strainRateFunction.C

@@ -0,0 +1,134 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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 "strainRateFunction.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+    defineTypeNameAndDebug(strainRateFunction, 0);
+
+    addToRunTimeSelectionTable
+    (
+        generalizedNewtonianViscosityModel,
+        strainRateFunction,
+        dictionary
+    );
+}
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::laminarModels::generalizedNewtonianViscosityModels::strainRateFunction::
+strainRateFunction
+(
+    const dictionary& viscosityProperties
+)
+:
+    generalizedNewtonianViscosityModel(viscosityProperties),
+    strainRateFunction_
+    (
+        Function1<scalar>::New
+        (
+            "function",
+            viscosityProperties.optionalSubDict(typeName + "Coeffs")
+        )
+    )
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+bool Foam::laminarModels::generalizedNewtonianViscosityModels::
+strainRateFunction::read
+(
+    const dictionary& viscosityProperties
+)
+{
+    generalizedNewtonianViscosityModel::read(viscosityProperties);
+
+    strainRateFunction_.clear();
+    strainRateFunction_ = Function1<scalar>::New
+    (
+        "function",
+        viscosityProperties.optionalSubDict
+        (
+            typeName + "Coeffs"
+        )
+    );
+
+    return true;
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::laminarModels::generalizedNewtonianViscosityModels::strainRateFunction::
+nu
+(
+    const volScalarField& nu0,
+    const volScalarField& strainRate
+) const
+{
+    tmp<volScalarField> tnu
+    (
+        new volScalarField
+        (
+            IOobject
+            (
+                IOobject::groupName(type() + ":nu", nu0.group()),
+                nu0.time().timeName(),
+                nu0.db(),
+                IOobject::NO_READ,
+                IOobject::AUTO_WRITE
+            ),
+            nu0.mesh(),
+            dimensionedScalar("0", dimViscosity, 0)
+        )
+    );
+
+    tnu.ref().primitiveFieldRef() = strainRateFunction_->value(strainRate);
+
+    volScalarField::Boundary& nuBf = tnu.ref().boundaryFieldRef();
+    const volScalarField::Boundary& sigmaBf = strainRate.boundaryField();
+
+    forAll(nuBf, patchi)
+    {
+        nuBf[patchi] = strainRateFunction_->value(sigmaBf[patchi]);
+    }
+
+    return tnu;
+}
+
+
+// ************************************************************************* //

src/TurbulenceModels/turbulenceModels/laminar/generalizedNewtonian/generalizedNewtonianViscosityModels/strainRateFunction/strainRateFunction.H

@@ -0,0 +1,116 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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::laminarModels::generalizedNewtonianViscosityModels::strainRateFunction
+
+Description
+    Run-time selected strain-rate function generalized Newtonian viscosity model
+
+    Example linear function of strain-rate:
+    \verbatim
+        generalizedNewtonianModel strainRateFunction;
+
+        function polynomial ((0 0.1) (1 1.3));
+    \endverbatim
+
+See also
+    Foam::generalizedNewtonianViscosityModel
+    Foam::Function1
+
+SourceFiles
+    strainRateFunction.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef strainRateFunction_H
+#define strainRateFunction_H
+
+#include "generalizedNewtonianViscosityModel.H"
+#include "Function1.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace laminarModels
+{
+namespace generalizedNewtonianViscosityModels
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class strainRateFunction Declaration
+\*---------------------------------------------------------------------------*/
+
+class strainRateFunction
+:
+    public generalizedNewtonianViscosityModel
+{
+    // Private data
+
+        //- Strain-rate function
+        autoPtr<Function1<scalar>> strainRateFunction_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("strainRateFunction");
+
+
+    // Constructors
+
+        //- Construct from components
+        strainRateFunction(const dictionary& viscosityProperties);
+
+
+    //- Destructor
+    virtual ~strainRateFunction()
+    {}
+
+
+    // Member Functions
+
+        //- Read transportProperties dictionary
+        virtual bool read(const dictionary& viscosityProperties);
+
+        //- Return the laminar viscosity
+        virtual tmp<volScalarField> nu
+        (
+            const volScalarField& nu0,
+            const volScalarField& strainRate
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace generalizedNewtonianViscosityModels
+} // End namespace laminarModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //