driftFluxFoam::relativeVelocityModels: Added MichaelsBolger model for flocculated suspensions

Description
    Michaels & Bolger relative velocity model

    Reference:
    \verbatim
        Michaels, A. S., & Bolger, J. C. (1962).
        Settling rates and sediment volumes
        of flocculated kaolin suspensions.
        Industrial & Engineering Chemistry Fundamentals, 1(1), 24-33.
    \endverbatim

Usage
    Example usage:
    \verbatim
        relativeVelocityModel MichaelsBolger;

        MichaelsBolgerCoeffs
        {
            a0          0;    // Extended Michaels & Bolger coefficient,
            a1          4.65; // Exponent

            alphaMax    0.6;  // Maximum dispersed phase-fraction
                              // (packing fraction)
        }
    \endverbatim

applications/solvers/multiphase/driftFluxFoam/incompressibleTwoPhaseInteractingMixture/incompressibleTwoPhaseInteractingMixture.C

@@ -24,6 +24,7 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "incompressibleTwoPhaseInteractingMixture.H"
+#include "mixtureViscosityModel.H"
 #include "relativeVelocityModel.H"
 #include "fvcDiv.H"
 #include "addToRunTimeSelectionTable.H"
@@ -48,7 +49,9 @@ incompressibleTwoPhaseInteractingMixture
 :
     twoPhaseMixture(U.mesh()),
 
-    muModel_(mixtureViscosityModel::New(U.mesh(), phase1Name())),
+    U_(U),
+
+    muModel_(mixtureViscosityModel::New(*this)),
     nucModel_(viscosityModel::New(U.mesh(), phase2Name())),
 
     rhod_("rho", dimDensity, muModel_()),
@@ -59,9 +62,7 @@ incompressibleTwoPhaseInteractingMixture
         dimLength,
         muModel_->lookupOrDefault("d", 0.0)
     ),
-    alphaMax_(muModel_->lookupOrDefault("alphaMax", 1.0)),
+    alphaMax_(lookupOrDefault("alphaMax", 1.0)),
-
-    U_(U),
 
     g_(g),
 
@@ -95,6 +96,20 @@ Foam::incompressibleTwoPhaseInteractingMixture::
 
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
+const Foam::volScalarField&
+Foam::incompressibleTwoPhaseInteractingMixture::alphad() const
+{
+    return alpha1();
+}
+
+
+const Foam::volScalarField&
+Foam::incompressibleTwoPhaseInteractingMixture::alphac() const
+{
+    return alpha2();
+}
+
+
 const Foam::mixtureViscosityModel&
 Foam::incompressibleTwoPhaseInteractingMixture::muModel() const
 {

applications/solvers/multiphase/driftFluxFoam/incompressibleTwoPhaseInteractingMixture/incompressibleTwoPhaseInteractingMixture.H

@@ -39,7 +39,6 @@ SourceFiles
 
 #include "twoPhaseMixture.H"
 #include "viscosityModel.H"
-#include "mixtureViscosityModel.H"
 #include "uniformDimensionedFields.H"
 #include "IOMRFZoneList.H"
 
@@ -48,6 +47,7 @@ SourceFiles
 namespace Foam
 {
 
+class mixtureViscosityModel;
 class relativeVelocityModel;
 
 /*---------------------------------------------------------------------------*\
@@ -61,6 +61,8 @@ class incompressibleTwoPhaseInteractingMixture
 {
     // Private data
 
+        volVectorField& U_;
+
         autoPtr<mixtureViscosityModel> muModel_;
         autoPtr<viscosityModel> nucModel_;
 
@@ -73,8 +75,6 @@ class incompressibleTwoPhaseInteractingMixture
         //- Optional maximum dispersed phase-fraction (e.g. packing limit)
         scalar alphaMax_;
 
-        volVectorField& U_;
-
         //- Acceleration due to gravity
         const uniformDimensionedVectorField& g_;
 
@@ -109,6 +109,12 @@ public:
 
     // Member Functions
 
+        //- Return const-access to the continuous phase-fraction
+        const volScalarField& alphac() const;
+
+        //- Return const-access to the dispersed phase-fraction
+        const volScalarField& alphad() const;
+
         //- Return const-access to the mixture viscosityModel
         const mixtureViscosityModel& muModel() const;
 

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/BinghamPlastic/BinghamPlastic.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2014-2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2014-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -49,11 +49,10 @@ namespace mixtureViscosityModels
 
 Foam::mixtureViscosityModels::BinghamPlastic::BinghamPlastic
 (
-    const fvMesh& mesh,
+    const incompressibleTwoPhaseInteractingMixture& mixture
-    const word& group
 )
 :
-    plastic(mesh, group),
+    plastic(mixture),
     yieldStressCoeff_
     (
         "BinghamCoeff",
@@ -95,7 +94,7 @@ Foam::mixtureViscosityModels::BinghamPlastic::mu
                 (
                     log10(vGreat),
                     yieldStressExponent_
-                   *(max(alpha_, scalar(0)) + yieldStressOffset_)
+                   *(max(mixture_.alphad(), scalar(0)) + yieldStressOffset_)
                 )
             )
           - pow

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/BinghamPlastic/BinghamPlastic.H

@@ -74,8 +74,11 @@ public:
 
     // Constructors
 
-        //- Construct from components
+        //- Construct from mixture
-        BinghamPlastic(const fvMesh& mesh, const word& group);
+        BinghamPlastic
+        (
+            const incompressibleTwoPhaseInteractingMixture& mixture
+        );
 
 
     //- Destructor

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/Make/options

@@ -2,9 +2,12 @@ EXE_INC = \
     -I../incompressibleTwoPhaseInteractingMixture \
     -I$(LIB_SRC)/finiteVolume/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
-    -I$(LIB_SRC)/twoPhaseModels/twoPhaseMixture/lnInclude
+    -I$(LIB_SRC)/twoPhaseModels/twoPhaseMixture/lnInclude \
+    -I$(LIB_SRC)/finiteVolume/lnInclude \
+    -I$(LIB_SRC)/meshTools/lnInclude
 
 LIB_LIBS = \
     -ltwoPhaseMixture \
     -lphysicalProperties \
-    -lfiniteVolume
+    -lfiniteVolume \
+    -lmeshTools

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/Quemada/Quemada.C

@@ -49,34 +49,16 @@ namespace mixtureViscosityModels
 
 Foam::mixtureViscosityModels::Quemada::Quemada
 (
-    const fvMesh& mesh,
+    const incompressibleTwoPhaseInteractingMixture& mixture
-    const word& group
 )
 :
-    mixtureViscosityModel(mesh, group),
+    mixtureViscosityModel(mixture),
-    alphaMax_
-    (
-        "alphaMax",
-        dimless,
-        optionalSubDict(typeName + "Coeffs").lookup("alphaMax")
-    ),
     q_(optionalSubDict(typeName + "Coeffs").lookupOrDefault("q", scalar(2))),
     muMax_
     (
         "muMax",
         dimDynamicViscosity,
         optionalSubDict(typeName + "Coeffs").lookup("muMax")
-    ),
-    alpha_
-    (
-        mesh.lookupObject<volScalarField>
-        (
-            IOobject::groupName
-            (
-                lookupOrDefault<word>("alpha", "alpha"),
-                group
-            )
-        )
     )
 {}
 
@@ -90,7 +72,11 @@ Foam::mixtureViscosityModels::Quemada::mu
     const volVectorField& U
 ) const
 {
-    return min(muc*pow(1.0 - alpha_/alphaMax_, -q_), muMax_);
+    return min
+    (
+        muc*pow(max(1 - mixture_.alphad()/mixture_.alphaMax(), 0.0), -q_),
+        muMax_
+    );
 }
 
 
@@ -100,8 +86,8 @@ bool Foam::mixtureViscosityModels::Quemada::read()
     {
         const dictionary& dict = optionalSubDict(typeName + "Coeffs");
 
-        dict.lookup("alphaMax") >> alphaMax_;
         dict.lookup("q") >> q_;
+        dict.lookup("muMax") >> muMax_;
 
         return true;
     }

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/Quemada/Quemada.H

@@ -40,10 +40,11 @@ Usage
     \verbatim
         viscosityModel  Quemada;
 
-        alphaMax    0.6; // Maximum dispersed phase-fraction (packing fraction)
+        rho         1996; // Dispersed phase density
-        q           2;   // Exponent, defaults to 2
+
+        q           2;    // Exponent, defaults to 2
+        muMax       1e-2; // Maximum viscosity (for numerical stability)
 
-        rho         1996;
     \endverbatim
 
 SourceFiles
@@ -75,18 +76,12 @@ class Quemada
 {
     // Private data
 
-        //- Maximum dispersed phase-fraction (packing fraction)
-        dimensionedScalar alphaMax_;
-
         //- Exponent (defaults to 2)
         scalar q_;
 
         //- Maximum viscosity
         dimensionedScalar muMax_;
 
-        //- Dispersed phase fraction
-        const volScalarField& alpha_;
-
 
 public:
 
@@ -96,8 +91,8 @@ public:
 
     // Constructors
 
-        //- Construct from components
+        //- Construct from mixture
-        Quemada(const fvMesh& mesh, const word& group);
+        Quemada(const incompressibleTwoPhaseInteractingMixture& mixture);
 
 
     //- Destructor

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/mixtureViscosityModel/mixtureViscosityModel.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2014-2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2014-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -39,11 +39,11 @@ namespace Foam
 
 Foam::mixtureViscosityModel::mixtureViscosityModel
 (
-    const fvMesh& mesh,
+    const incompressibleTwoPhaseInteractingMixture& mixture
-    const word& group
 )
 :
-    viscosityModel(mesh, group)
+    viscosityModel(mixture.U().mesh(), mixture.phase1Name()),
+    mixture_(mixture)
 {}
 
 

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/mixtureViscosityModel/mixtureViscosityModel.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2014-2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2014-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -42,7 +42,7 @@ SourceFiles
 #ifndef mixtureViscosityModel_H
 #define mixtureViscosityModel_H
 
-#include "dictionary.H"
+#include "incompressibleTwoPhaseInteractingMixture.H"
 #include "viscosityModel.H"
 #include "runTimeSelectionTables.H"
 
@@ -60,6 +60,14 @@ class mixtureViscosityModel
     public viscosityModel
 {
 
+protected:
+
+    // Protected data
+
+        //- Mixture properties
+        const incompressibleTwoPhaseInteractingMixture& mixture_;
+
+
 public:
 
     //- Runtime type information
@@ -74,20 +82,22 @@ public:
             mixtureViscosityModel,
             dictionary,
             (
-                const fvMesh& mesh,
+                const incompressibleTwoPhaseInteractingMixture& mixture
-                const word& group
             ),
-            (mesh, group)
+            (mixture)
         );
 
 
     // Constructors
 
-        //- Construct from components
+        //- Construct from mixture
-        mixtureViscosityModel(const fvMesh& U, const word& group);
+        mixtureViscosityModel
+        (
+            const incompressibleTwoPhaseInteractingMixture& mixture
+        );
 
         //- Disallow default bitwise copy construction
-        mixtureViscosityModel(const mixtureViscosityModel&);
+        mixtureViscosityModel(const mixtureViscosityModel&) = delete;
 
 
     // Selectors
@@ -95,8 +105,7 @@ public:
         //- Return a reference to the selected viscosity model
         static autoPtr<mixtureViscosityModel> New
         (
-            const fvMesh& mesh,
+            const incompressibleTwoPhaseInteractingMixture& mixture
-            const word& group
         );
 
 

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/mixtureViscosityModel/mixtureViscosityModelNew.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2014-2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2014-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -31,15 +31,18 @@ License
 
 Foam::autoPtr<Foam::mixtureViscosityModel> Foam::mixtureViscosityModel::New
 (
-    const fvMesh& mesh,
+    const incompressibleTwoPhaseInteractingMixture& mixture
-    const word& group
 )
 {
     const word modelType
     (
         IOdictionary
         (
-            viscosityModel::findModelDict(mesh, group)
+            viscosityModel::findModelDict
+            (
+                mixture.U().mesh(),
+                mixture.phase1Name()
+            )
         ).lookup("viscosityModel")
     );
 
@@ -58,7 +61,7 @@ Foam::autoPtr<Foam::mixtureViscosityModel> Foam::mixtureViscosityModel::New
             << exit(FatalError);
     }
 
-    return autoPtr<mixtureViscosityModel>(cstrIter()(mesh, group));
+    return autoPtr<mixtureViscosityModel>(cstrIter()(mixture));
 }
 
 

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/plastic/plastic.C

@@ -48,11 +48,10 @@ namespace mixtureViscosityModels
 
 Foam::mixtureViscosityModels::plastic::plastic
 (
-    const fvMesh& mesh,
+    const incompressibleTwoPhaseInteractingMixture& mixture
-    const word& group
 )
 :
-    mixtureViscosityModel(mesh, group),
+    mixtureViscosityModel(mixture),
     plasticCoeffs_(optionalSubDict(typeName + "Coeffs")),
     plasticViscosityCoeff_
     (
@@ -66,18 +65,7 @@ Foam::mixtureViscosityModels::plastic::plastic
         dimless,
         plasticCoeffs_.lookup("exponent")
     ),
-    muMax_("muMax", dimDynamicViscosity, plasticCoeffs_.lookup("muMax")),
+    muMax_("muMax", dimDynamicViscosity, plasticCoeffs_.lookup("muMax"))
-    alpha_
-    (
-        mesh.lookupObject<volScalarField>
-        (
-            IOobject::groupName
-            (
-                lookupOrDefault<word>("alpha", "alpha"),
-                group
-            )
-        )
-    )
 {}
 
 
@@ -98,7 +86,7 @@ Foam::mixtureViscosityModels::plastic::mu
             pow
             (
                 scalar(10),
-                plasticViscosityExponent_*alpha_
+                plasticViscosityExponent_*mixture_.alphad()
             ) - scalar(1)
         ),
         muMax_

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/plastic/plastic.H

@@ -73,9 +73,6 @@ protected:
         //- Maximum viscosity
         dimensionedScalar muMax_;
 
-        //- Plastic phase fraction
-        const volScalarField& alpha_;
-
 
 public:
 
@@ -85,8 +82,8 @@ public:
 
     // Constructors
 
-        //- Construct from components
+        //- Construct from mixture
-        plastic(const fvMesh& mesh, const word& group);
+        plastic(const incompressibleTwoPhaseInteractingMixture& mixture);
 
 
     //- Destructor

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/slurry/slurry.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2014-2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2014-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -48,22 +48,10 @@ namespace mixtureViscosityModels
 
 Foam::mixtureViscosityModels::slurry::slurry
 (
-    const fvMesh& mesh,
+    const incompressibleTwoPhaseInteractingMixture& mixture
-    const word& group
 )
 :
-    mixtureViscosityModel(mesh, group),
+    mixtureViscosityModel(mixture)
-    alpha_
-    (
-        mesh.lookupObject<volScalarField>
-        (
-            IOobject::groupName
-            (
-                lookupOrDefault<word>("alpha", "alpha"),
-                group
-            )
-        )
-    )
 {}
 
 
@@ -76,9 +64,11 @@ Foam::mixtureViscosityModels::slurry::mu
     const volVectorField& U
 ) const
 {
+    const volScalarField& alphad = mixture_.alphad();
+
     return
     (
-        muc*(1.0 + 2.5*alpha_ + 10.05*sqr(alpha_) + 0.00273*exp(16.6*alpha_))
+        muc*(1.0 + 2.5*alphad + 10.05*sqr(alphad) + 0.00273*exp(16.6*alphad))
     );
 }
 

applications/solvers/multiphase/driftFluxFoam/mixtureViscosityModels/slurry/slurry.H

@@ -66,11 +66,6 @@ class slurry
 :
     public mixtureViscosityModel
 {
-    // Private data
-
-        //- Slurry phase fraction
-        const volScalarField& alpha_;
-
 
 public:
 
@@ -80,8 +75,8 @@ public:
 
     // Constructors
 
-        //- Construct from components
+        //- Construct from mixture
-        slurry(const fvMesh& mesh, const word& group);
+        slurry(const incompressibleTwoPhaseInteractingMixture& mixture);
 
 
     //- Destructor

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/Make/files

@@ -1,5 +1,6 @@
 relativeVelocityModel/relativeVelocityModel.C
 simple/simple.C
 general/general.C
+MichaelsBolger/MichaelsBolger.C
 
 LIB = $(FOAM_LIBBIN)/libdriftFluxRelativeVelocityModels

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/MichaelsBolger/MichaelsBolger.C

@@ -0,0 +1,80 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2022 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 "MichaelsBolger.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace relativeVelocityModels
+{
+    defineTypeNameAndDebug(MichaelsBolger, 0);
+    addToRunTimeSelectionTable
+    (
+        relativeVelocityModel,
+        MichaelsBolger,
+        dictionary
+    );
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::relativeVelocityModels::MichaelsBolger::MichaelsBolger
+(
+    const dictionary& dict,
+    const incompressibleTwoPhaseInteractingMixture& mixture,
+    const uniformDimensionedVectorField& g
+)
+:
+    relativeVelocityModel(dict, mixture, g),
+    a0_("a0", dimless, dict),
+    a1_("a1", dimless, dict),
+    alphaMax_("alphaMax", dimless, dict),
+    Vc_("Vc", dimTime, dict)
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::relativeVelocityModels::MichaelsBolger::~MichaelsBolger()
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+void Foam::relativeVelocityModels::MichaelsBolger::correct()
+{
+    Udm_ =
+        (mixture_.rhoc()/mixture_.rho())*Vc_
+       *(a0_ + pow(max(1 - mixture_.alphad()/mixture().alphaMax(), 0.0), a1_))
+       *acceleration();
+}
+
+
+// ************************************************************************* //

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/MichaelsBolger/MichaelsBolger.H

@@ -0,0 +1,130 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2022 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::relativeVelocityModels::MichaelsBolger
+
+Description
+    Michaels & Bolger relative velocity model
+
+    Reference:
+    \verbatim
+        Michaels, A. S., & Bolger, J. C. (1962).
+        Settling rates and sediment volumes
+        of flocculated kaolin suspensions.
+        Industrial & Engineering Chemistry Fundamentals, 1(1), 24-33.
+    \endverbatim
+
+Usage
+    Example usage:
+    \verbatim
+        relativeVelocityModel MichaelsBolger;
+
+        MichaelsBolgerCoeffs
+        {
+            a0          0;    // Extended Michaels & Bolger coefficient,
+            a1          4.65; // Exponent
+
+            alphaMax    0.6;  // Maximum dispersed phase-fraction
+                              // (packing fraction)
+        }
+    \endverbatim
+
+SourceFiles
+    MichaelsBolger.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef MichaelsBolger_H
+#define MichaelsBolger_H
+
+#include "relativeVelocityModel.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace relativeVelocityModels
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class MichaelsBolger Declaration
+\*---------------------------------------------------------------------------*/
+
+class MichaelsBolger
+:
+    public relativeVelocityModel
+{
+    // Private Data
+
+        //- Extended Michaels & Bolger coefficient, defaults to 0
+        dimensionedScalar a0_;
+
+        //- Exponent, defaults to 4.65
+        dimensionedScalar a1_;
+
+        //- alphaMax coefficient
+        dimensionedScalar alphaMax_;
+
+        //- Drift velocity coefficient
+        dimensionedScalar Vc_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("MichaelsBolger");
+
+
+    // Constructors
+
+        //- Construct from components
+        MichaelsBolger
+        (
+            const dictionary& dict,
+            const incompressibleTwoPhaseInteractingMixture& mixture,
+            const uniformDimensionedVectorField& g
+        );
+
+
+    //- Destructor
+    ~MichaelsBolger();
+
+
+    // Member Functions
+
+        //- Update the diffusion velocity
+        virtual void correct();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace relativeVelocityModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/general/general.C

@@ -65,11 +65,13 @@ Foam::relativeVelocityModels::general::~general()
 
 void Foam::relativeVelocityModels::general::correct()
 {
+    const volScalarField& alphad = mixture_.alphad();
+
     Udm_ =
-        (rhoc_/rho())*Vc_*acceleration()
+        (mixture_.rhoc()/mixture_.rho())*Vc_*acceleration()
        *(
-            exp(-a_*max(alphad_ - residualAlpha_, scalar(0)))
+            exp(-a_*max(alphad - residualAlpha_, scalar(0)))
-          - exp(-a1_*max(alphad_ - residualAlpha_, scalar(0)))
+          - exp(-a1_*max(alphad - residualAlpha_, scalar(0)))
         );
 }
 

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/relativeVelocityModel/relativeVelocityModel.C

@@ -76,22 +76,18 @@ Foam::relativeVelocityModel::relativeVelocityModel
 )
 :
     mixture_(mixture),
-    alphac_(mixture.alpha2()),
-    alphad_(mixture.alpha1()),
-    rhoc_(mixture.rhoc()),
-    rhod_(mixture.rhod()),
     g_(g),
     Udm_
     (
         IOobject
         (
             "Udm",
-            alphac_.time().timeName(),
+            mixture.U().time().timeName(),
-            alphac_.mesh(),
+            mixture.U().mesh(),
             IOobject::READ_IF_PRESENT,
             IOobject::AUTO_WRITE
         ),
-        alphac_.mesh(),
+        mixture_.U().mesh(),
         dimensionedVector(dimVelocity, Zero),
         UdmPatchFieldTypes()
     )
@@ -145,12 +141,6 @@ Foam::relativeVelocityModel::~relativeVelocityModel()
 
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
-Foam::tmp<Foam::volScalarField> Foam::relativeVelocityModel::rho() const
-{
-    return alphac_*rhoc_ + alphad_*rhod_;
-}
-
-
 Foam::tmp<Foam::volVectorField>
 Foam::relativeVelocityModel::acceleration() const
 {
@@ -162,8 +152,8 @@ Foam::relativeVelocityModel::acceleration() const
 
 Foam::tmp<Foam::volSymmTensorField> Foam::relativeVelocityModel::tauDm() const
 {
-    const volScalarField betac(alphac_*rhoc_);
+    const volScalarField betac(mixture_.alphac()*mixture_.rhoc());
-    const volScalarField betad(alphad_*rhod_);
+    const volScalarField betad(mixture_.alphad()*mixture_.rhod());
 
     // Calculate the relative velocity of the continuous phase w.r.t the mean
     const volVectorField Ucm(betad*Udm_/betac);

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/relativeVelocityModel/relativeVelocityModel.H

@@ -62,27 +62,13 @@ protected:
         //- Mixture properties
         const incompressibleTwoPhaseInteractingMixture& mixture_;
 
-        //- Name of the continuous phase
-        const word continuousPhaseName_;
-
-        //- Continuous phase fraction
-        const volScalarField& alphac_;
-
-        //- Dispersed phase fraction
-        const volScalarField& alphad_;
-
-        //- Continuous density
-        const dimensionedScalar& rhoc_;
-
-        //- Dispersed density
-        const dimensionedScalar& rhod_;
-
         //- Acceleration due to gravity
         const uniformDimensionedVectorField& g_;
 
         //- Dispersed diffusion velocity
         mutable volVectorField Udm_;
 
+
 public:
 
     //- Runtime type information
@@ -138,9 +124,6 @@ public:
             return mixture_;
         }
 
-        //- Return the mixture mean density
-        tmp<volScalarField> rho() const;
-
         //- Return the diffusion velocity of the dispersed phase
         const volVectorField& Udm() const
         {

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/simple/simple.C

@@ -49,8 +49,7 @@ Foam::relativeVelocityModels::simple::simple
 :
     relativeVelocityModel(dict, mixture, g),
     a_("a", dimless, dict),
-    Vc_("Vc", dimTime, dict),
+    Vc_("Vc", dimTime, dict)
-    residualAlpha_("residualAlpha", dimless, dict)
 {}
 
 
@@ -65,8 +64,8 @@ Foam::relativeVelocityModels::simple::~simple()
 void Foam::relativeVelocityModels::simple::correct()
 {
     Udm_ =
-        (rhoc_/rho())*Vc_*acceleration()
+        (mixture_.rhoc()/mixture_.rho())*Vc_*acceleration()
-       *pow(scalar(10), -a_*max(alphad_, scalar(0)));
+       *pow(scalar(10), -a_*max(mixture_.alphad(), scalar(0)));
 }
 
 

applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/simple/simple.H

@@ -60,9 +60,6 @@ class simple
         //- Drift velocity coefficient
         dimensionedScalar Vc_;
 
-        //- Residual phase fraction
-        dimensionedScalar residualAlpha_;
-
 
 public: