filmViscosityModel/ArrheniusViscosity: temperature-dependent viscosity function

Applied as a correction pre-factor to the viscosity obtained from a
run-time selectable base-model.

src/regionModels/surfaceFilmModels/Make/files

@@ -56,6 +56,7 @@ $(THERMOMODELS)/filmViscosityModel/filmViscosityModel/filmViscosityModelNew.C
 $(THERMOMODELS)/filmViscosityModel/constantViscosity/constantViscosity.C
 $(THERMOMODELS)/filmViscosityModel/liquidViscosity/liquidViscosity.C
 $(THERMOMODELS)/filmViscosityModel/thixotropicViscosity/thixotropicViscosity.C
+$(THERMOMODELS)/filmViscosityModel/ArrheniusViscosity/ArrheniusViscosity.C
 
 
 /* Boundary conditions */

src/regionModels/surfaceFilmModels/submodels/thermo/filmViscosityModel/ArrheniusViscosity/ArrheniusViscosity.C

@@ -0,0 +1,93 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2015 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 "ArrheniusViscosity.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace regionModels
+{
+namespace surfaceFilmModels
+{
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+defineTypeNameAndDebug(ArrheniusViscosity, 0);
+
+addToRunTimeSelectionTable
+(
+    filmViscosityModel,
+    ArrheniusViscosity,
+    dictionary
+);
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+ArrheniusViscosity::ArrheniusViscosity
+(
+    surfaceFilmModel& owner,
+    const dictionary& dict,
+    volScalarField& mu
+)
+:
+    filmViscosityModel(typeName, owner, dict, mu),
+    viscosity_(filmViscosityModel::New(owner, coeffDict_, mu)),
+    k1_("k1", dimTemperature, coeffDict_.lookup("k1")),
+    k2_("k2", dimTemperature, coeffDict_.lookup("k2")),
+    Tref_("Tref", dimTemperature, coeffDict_.lookup("Tref"))
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+ArrheniusViscosity::~ArrheniusViscosity()
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+void ArrheniusViscosity::correct
+(
+    const volScalarField& p,
+    const volScalarField& T
+)
+{
+    viscosity_->correct(p, T);
+    mu_ *= exp(k1_*((1/(T + k2_)) - 1/(Tref_ + k2_)));
+    mu_.correctBoundaryConditions();
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace surfaceFilmModels
+} // End namespace regionModels
+} // End namespace Foam
+
+// ************************************************************************* //

src/regionModels/surfaceFilmModels/submodels/thermo/filmViscosityModel/ArrheniusViscosity/ArrheniusViscosity.H

@@ -0,0 +1,134 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2015 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::ArrheniusViscosity
+
+Description
+    The Arrhenius temperature-dependent viscosity model multiplies the viscosity
+    of a base model by an Arrhenius-type temperature function:
+
+        mu = mu0*exp(k1*(1/(T + k2) - 1/(Tref + k2)))
+
+    Where:
+        mu0 is the base-model viscosity
+        k1 and k2 are Arrhenius coefficients
+        T is the local temperature
+        Tref is the reference temperature
+
+SourceFiles
+    ArrheniusViscosity.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef ArrheniusViscosity_H
+#define ArrheniusViscosity_H
+
+#include "filmViscosityModel.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace regionModels
+{
+namespace surfaceFilmModels
+{
+
+/*---------------------------------------------------------------------------*\
+                    Class ArrheniusViscosity Declaration
+\*---------------------------------------------------------------------------*/
+
+class ArrheniusViscosity
+:
+    public filmViscosityModel
+{
+    // Private member functions
+
+        //- Disallow default bitwise copy construct
+        ArrheniusViscosity(const ArrheniusViscosity&);
+
+        //- Disallow default bitwise assignment
+        void operator=(const ArrheniusViscosity&);
+
+
+protected:
+
+    // Protected data
+
+        //- Base viscosity model
+        autoPtr<filmViscosityModel> viscosity_;
+
+        //- Coefficient k1
+        dimensionedScalar k1_;
+
+        //- Coefficient k2
+        dimensionedScalar k2_;
+
+        //- Reference temperature
+        dimensionedScalar Tref_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("Arrhenius");
+
+
+    // Constructors
+
+        //- Construct from surface film model
+        ArrheniusViscosity
+        (
+            surfaceFilmModel& owner,
+            const dictionary& dict,
+            volScalarField& mu
+        );
+
+
+    //- Destructor
+    virtual ~ArrheniusViscosity();
+
+
+    // Member Functions
+
+        //- Correct
+        virtual void correct
+        (
+            const volScalarField& p,
+            const volScalarField& T
+        );
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace surfaceFilmModels
+} // End namespace regionModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/regionModels/surfaceFilmModels/submodels/thermo/filmViscosityModel/thixotropicViscosity/thixotropicViscosity.C

@@ -53,33 +53,6 @@ addToRunTimeSelectionTable
 );
 
 
-// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
-
-void thixotropicViscosity::updateMu()
-{
-    const kinematicSingleLayer& film = filmType<kinematicSingleLayer>();
-
-    // Blend based on mass fraction of added- to existing film mass
-    const dimensionedScalar m0("zero", dimMass, 0.0);
-    const dimensionedScalar mSMALL("SMALL", dimMass, ROOTVSMALL);
-    const volScalarField deltaMass("deltaMass", max(m0, film.deltaMass()));
-    const volScalarField filmMass("filmMass", film.netMass() + mSMALL);
-
-    // Weighting field to blend new and existing mass contributions
-    const volScalarField w
-    (
-        "w",
-        max(scalar(0.0), min(scalar(1.0), deltaMass/(deltaMass + filmMass)))
-    );
-
-    mu_ =
-        w*muInf_
-      + (1 - w)*muInf_/(sqr(1.0 - K_*lambda_) + ROOTVSMALL);
-
-    mu_.correctBoundaryConditions();
-}
-
-
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 thixotropicViscosity::thixotropicViscosity
@@ -113,9 +86,7 @@ thixotropicViscosity::thixotropicViscosity
     lambda_.min(1.0);
     lambda_.max(0.0);
 
-    // Initialise viscosity to inf value
+    // Initialise viscosity to inf value because it cannot be evaluated yet
-    // - cannot call updateMu() since this calls film.netMass() which
-    //   cannot be evaluated yet (still in construction)
     mu_ = muInf_;
     mu_.correctBoundaryConditions();
 }
@@ -177,7 +148,30 @@ void thixotropicViscosity::correct
     lambda_.min(1.0);
     lambda_.max(0.0);
 
-    updateMu();
+
+    // Blend based on mass fraction of added- to existing film mass
+    const dimensionedScalar m0("zero", dimMass, 0.0);
+    const dimensionedScalar mSMALL("SMALL", dimMass, ROOTVSMALL);
+    const volScalarField deltaMass
+    (
+        "thixotropicViscosity:deltaMass",
+        max(m0, film.deltaMass())
+    );
+    const volScalarField filmMass
+    (
+        "thixotropicViscosity:filmMass",
+        film.netMass() + mSMALL
+    );
+
+    // Weighting field to blend new and existing mass contributions
+    const volScalarField w
+    (
+        "thixotropicViscosity:w",
+        max(scalar(0.0), min(scalar(1.0), deltaMass/(deltaMass + filmMass)))
+    );
+
+    mu_ = w*muInf_ + (1 - w)*muInf_/(sqr(1.0 - K_*lambda_) + ROOTVSMALL);
+    mu_.correctBoundaryConditions();
 }
 
 

src/regionModels/surfaceFilmModels/submodels/thermo/filmViscosityModel/thixotropicViscosity/thixotropicViscosity.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2013-2014 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2013-2015 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -56,7 +56,6 @@ Description
         \mu_{\infty}    | limiting viscosity when \f$ \lambda = 0 \f$
     \endvartable
 
-
     Reference:
     \verbatim
         Barnes H A, 1997.  Thixotropy - a review.  J. Non-Newtonian Fluid
@@ -90,8 +89,6 @@ class thixotropicViscosity
 :
     public filmViscosityModel
 {
-private:
-
     // Private member functions
 
         //- Disallow default bitwise copy construct
@@ -132,12 +129,6 @@ protected:
         volScalarField lambda_;
 
 
-    // Protected Member Functions
-
-        //- Update the viscosity
-        void updateMu();
-
-
 public:
 
     //- Runtime type information
@@ -161,14 +152,12 @@ public:
 
     // Member Functions
 
-        // Evolution
+        //- Correct
-
+        virtual void correct
-            //- Correct
+        (
-            virtual void correct
+            const volScalarField& p,
-            (
+            const volScalarField& T
-                const volScalarField& p,
+        );
-                const volScalarField& T
-            );
 };