From 06893a0bc6f661c8a8579e83b38caaaa54979905 Mon Sep 17 00:00:00 2001
From: Henry Weller <http://cfd.direct>
Date: Fri, 6 Jan 2023 16:51:10 +0000
Subject: [PATCH] VoFSolver: New base-class for twoPhaseVoFSolver and
 multiphaseVoFSolver

Much of the VoF functionality, particularly relating to momentum solution, is
independent of the number of phases and it is useful to hold this generic VoF
data and functionality in an abstract base-class and derive twoPhaseVoFSolver
and multiphaseVoFSolver from it, adding two-phase and multiphase functionality
respectively.
---
 .gitignore                                    |   5 +-
 applications/solvers/modules/Allwmake         |   1 +
 .../solvers/modules/VoFSolver/Make/files      |   2 +-
 .../modules/VoFSolver/VoFMixture/VoFMixture.C |  41 ++++
 .../modules/VoFSolver/VoFMixture/VoFMixture.H |  92 +++++++++
 .../solvers/modules/VoFSolver/VoFSolver.C     |  93 ++-------
 .../solvers/modules/VoFSolver/VoFSolver.H     |  61 ++----
 .../solvers/modules/VoFSolver/alphaSuSp.H     |  19 --
 .../modules/VoFSolver/momentumPredictor.C     |   4 +-
 .../solvers/modules/VoFSolver/moveMesh.C      |   4 +-
 .../solvers/modules/VoFSolver/setRDeltaT.C    |  86 +-------
 .../modules/compressibleVoF/Make/options      |   3 +-
 .../compressibleTwoPhaseMixture.C             |   4 +-
 .../compressibleTwoPhaseMixture.H             |   4 +-
 .../modules/compressibleVoF/compressibleVoF.C |  12 +-
 .../modules/compressibleVoF/compressibleVoF.H |   7 +-
 .../fvModels/VoFCavitation/Make/options       |   2 +
 .../fvModels/VoFClouds/Make/options           |   2 +
 .../Make/options                              |   2 +
 .../fvModels/VoFSurfaceFilm/Make/options      |   2 +
 .../VoFTurbulenceDamping/Make/options         |   2 +
 .../modules/incompressibleVoF/Make/options    |   3 +-
 .../fvModels/VoFCavitation/Make/options       |   2 +
 .../VoFTurbulenceDamping/Make/options         |   2 +
 .../incompressibleTwoPhaseMixture.C           |   4 +-
 .../incompressibleTwoPhaseMixture.H           |   4 +-
 .../incompressibleVoF/incompressibleVoF.C     |  10 +-
 .../incompressibleVoF/incompressibleVoF.H     |   7 +-
 .../modules/twoPhaseVoFSolver/Make/files      |   6 +
 .../modules/twoPhaseVoFSolver/Make/options    |  24 +++
 .../alphaPredictor.C                          |  11 +-
 .../twoPhaseVoFSolver/setInterfaceRDeltaT.C   | 133 ++++++++++++
 .../twoPhaseVoFMixture/twoPhaseVoFMixture.C   |  44 ++++
 .../twoPhaseVoFMixture/twoPhaseVoFMixture.H   |  93 +++++++++
 .../twoPhaseVoFSolver/twoPhaseVoFSolver.C     | 164 +++++++++++++++
 .../twoPhaseVoFSolver/twoPhaseVoFSolver.H     | 195 ++++++++++++++++++
 36 files changed, 888 insertions(+), 262 deletions(-)
 create mode 100644 applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.C
 create mode 100644 applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.H
 delete mode 100644 applications/solvers/modules/VoFSolver/alphaSuSp.H
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/Make/files
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/Make/options
 rename applications/solvers/modules/{VoFSolver => twoPhaseVoFSolver}/alphaPredictor.C (97%)
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/setInterfaceRDeltaT.C
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.C
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.H
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.C
 create mode 100644 applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.H

diff --git a/.gitignore b/.gitignore
index a148a68efe..4d6083623e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -82,5 +82,8 @@ doc/Doxygen/DTAGS
 /.dir-locals.el
 /.ycm*
 
-# Ignore the test directory
+# Ignore the tutorials/log file
+/tutorials/log
+
+# Ignore the tutorialsTest directory
 /tutorialsTest
diff --git a/applications/solvers/modules/Allwmake b/applications/solvers/modules/Allwmake
index d8a9c60a06..640eaccf22 100755
--- a/applications/solvers/modules/Allwmake
+++ b/applications/solvers/modules/Allwmake
@@ -11,6 +11,7 @@ wmake $targetType fluid
 wmake $targetType multicomponentFluid
 wmake $targetType XiFluid
 wmake $targetType VoFSolver
+wmake $targetType twoPhaseVoFSolver
 incompressibleVoF/Allwmake $targetType $*
 compressibleVoF/Allwmake $targetType $*
 multiphaseEuler/Allwmake $targetType $*
diff --git a/applications/solvers/modules/VoFSolver/Make/files b/applications/solvers/modules/VoFSolver/Make/files
index 3f151b257e..e76628212e 100644
--- a/applications/solvers/modules/VoFSolver/Make/files
+++ b/applications/solvers/modules/VoFSolver/Make/files
@@ -1,6 +1,6 @@
+VoFMixture/VoFMixture.C
 setRDeltaT.C
 moveMesh.C
-alphaPredictor.C
 momentumPredictor.C
 VoFSolver.C
 
diff --git a/applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.C b/applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.C
new file mode 100644
index 0000000000..d9aa7ab860
--- /dev/null
+++ b/applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.C
@@ -0,0 +1,41 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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 "VoFMixture.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(VoFMixture, 0);
+}
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::VoFMixture::VoFMixture(const fvMesh& mesh)
+{}
+
+
+// ************************************************************************* //
diff --git a/applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.H b/applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.H
new file mode 100644
index 0000000000..c00ec1e455
--- /dev/null
+++ b/applications/solvers/modules/VoFSolver/VoFMixture/VoFMixture.H
@@ -0,0 +1,92 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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::VoFMixture
+
+Description
+    Class to represent a VoF mixture
+
+SourceFiles
+    VoFMixture.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef VoFMixture_H
+#define VoFMixture_H
+
+#include "volFieldsFwd.H"
+#include "surfaceFieldsFwd.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+class fvMesh;
+
+/*---------------------------------------------------------------------------*\
+                       Class VoFMixture Declaration
+\*---------------------------------------------------------------------------*/
+
+class VoFMixture
+{
+
+public:
+
+    TypeName("VoFMixture");
+
+
+    // Constructors
+
+        //- Construct from components
+        VoFMixture(const fvMesh& mesh);
+
+
+    //- Destructor
+    virtual ~VoFMixture()
+    {}
+
+
+    // Member Functions
+
+        //- Return the mixture density
+        virtual const volScalarField& rho() const = 0;
+
+        //- Correct the mixture properties
+        virtual void correct() = 0;
+
+        //- Read base phaseProperties dictionary
+        virtual bool read() = 0;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/applications/solvers/modules/VoFSolver/VoFSolver.C b/applications/solvers/modules/VoFSolver/VoFSolver.C
index 61f42bed6d..b5c07f13db 100644
--- a/applications/solvers/modules/VoFSolver/VoFSolver.C
+++ b/applications/solvers/modules/VoFSolver/VoFSolver.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -41,38 +41,26 @@ namespace solvers
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-void Foam::solvers::VoFSolver::correctCoNum()
-{
-    fluidSolver::correctCoNum(phi);
-
-    const scalarField sumPhi
-    (
-        interface.nearInterface()().primitiveField()
-       *fvc::surfaceSum(mag(phi))().primitiveField()
-    );
-
-    alphaCoNum = 0.5*gMax(sumPhi/mesh.V().field())*runTime.deltaTValue();
-
-    const scalar meanAlphaCoNum =
-        0.5*(gSum(sumPhi)/gSum(mesh.V().field()))*runTime.deltaTValue();
-
-    Info<< "Interface Courant Number mean: " << meanAlphaCoNum
-        << " max: " << alphaCoNum << endl;
-}
-
-
 void Foam::solvers::VoFSolver::continuityErrors()
 {
     fluidSolver::continuityErrors(phi);
 }
 
 
+// * * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * //
+
+void Foam::solvers::VoFSolver::correctCoNum()
+{
+    fluidSolver::correctCoNum(phi);
+}
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::solvers::VoFSolver::VoFSolver
 (
     fvMesh& mesh,
-    autoPtr<twoPhaseMixture> mixturePtr
+    autoPtr<VoFMixture> mixturePtr
 )
 :
     fluidSolver(mesh),
@@ -80,21 +68,6 @@ Foam::solvers::VoFSolver::VoFSolver
     mixture_(mixturePtr),
     mixture(mixture_()),
 
-    alpha1(mixture.alpha1()),
-    alpha2(mixture.alpha2()),
-
-    alphaRestart
-    (
-        typeIOobject<surfaceScalarField>
-        (
-            IOobject::groupName("alphaPhi", alpha1.group()),
-            runTime.name(),
-            mesh,
-            IOobject::READ_IF_PRESENT,
-            IOobject::AUTO_WRITE
-        ).headerOk()
-    ),
-
     divAlphaName("div(phi,alpha)"),
 
     U
@@ -123,8 +96,6 @@ Foam::solvers::VoFSolver::VoFSolver
         linearInterpolate(U) & mesh.Sf()
     ),
 
-    interface(mixture, alpha1, alpha2, U),
-
     buoyancy(mesh),
 
     p_rgh(buoyancy.p_rgh),
@@ -144,31 +115,9 @@ Foam::solvers::VoFSolver::VoFSolver
         fvc::interpolate(rho)*phi
     ),
 
-    alphaPhi1
-    (
-        IOobject
-        (
-            IOobject::groupName("alphaPhi", alpha1.group()),
-            runTime.name(),
-            mesh,
-            IOobject::READ_IF_PRESENT,
-            IOobject::AUTO_WRITE
-        ),
-        phi*fvc::interpolate(alpha1)
-    ),
-
     MRF(mesh)
 {
-    // Read the controls
-    read();
-
     mesh.schemes().setFluxRequired(p_rgh.name());
-    mesh.schemes().setFluxRequired(alpha1.name());
-
-    if (alphaRestart)
-    {
-        Info << "Restarting alpha" << endl;
-    }
 
     if (mesh.dynamic())
     {
@@ -188,11 +137,7 @@ Foam::solvers::VoFSolver::VoFSolver
         );
     }
 
-    if (transient())
-    {
-        correctCoNum();
-    }
-    else if (LTS)
+    if (LTS)
     {
         Info<< "Using LTS" << endl;
 
@@ -268,11 +213,7 @@ void Foam::solvers::VoFSolver::preSolve()
     // Store divU from the previous mesh so that it can be mapped
     // and used in correctPhi to ensure the corrected phi has the
     // same divergence
-    if
-    (
-        correctPhi
-     && divergent()
-     && mesh.topoChanged())
+    if (correctPhi && divergent())
     {
         // Construct and register divU for mapping
         divU = new volScalarField
@@ -283,21 +224,13 @@ void Foam::solvers::VoFSolver::preSolve()
     }
 
     // Update the mesh for topology change, mesh to mesh mapping
-    const bool topoChanged = mesh.update();
-
-    // Do not apply previous time-step mesh compression flux
-    // if the mesh topology changed
-    if (topoChanged)
-    {
-        talphaPhi1Corr0.clear();
-    }
+    mesh.update();
 }
 
 
 void Foam::solvers::VoFSolver::prePredictor()
 {
     fvModels().correct();
-    alphaPredictor();
 }
 
 
diff --git a/applications/solvers/modules/VoFSolver/VoFSolver.H b/applications/solvers/modules/VoFSolver/VoFSolver.H
index 5aaeaebd07..20d0eac41f 100644
--- a/applications/solvers/modules/VoFSolver/VoFSolver.H
+++ b/applications/solvers/modules/VoFSolver/VoFSolver.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -56,7 +56,7 @@ See also
 #define VoFSolver_H
 
 #include "fluidSolver.H"
-#include "twoPhaseMixture.H"
+#include "VoFMixture.H"
 #include "interfaceProperties.H"
 #include "buoyancy.H"
 #include "pressureReference.H"
@@ -83,18 +83,9 @@ protected:
     // Phase properties
 
         //- The compressible two-phase mixture
-        autoPtr<twoPhaseMixture> mixture_;
+        autoPtr<VoFMixture> mixture_;
 
-        twoPhaseMixture& mixture;
-
-        //- Reference to the phase1-fraction
-        volScalarField& alpha1;
-
-        //- Reference to the phase2-fraction
-        volScalarField& alpha2;
-
-        //- Switch indicating if this is a restart
-        bool alphaRestart;
+        VoFMixture& mixture;
 
         //- Name of the alpha convection scheme
         const word divAlphaName;
@@ -112,11 +103,6 @@ protected:
         surfaceScalarField phi;
 
 
-    // Interface properties
-
-        interfaceProperties interface;
-
-
     // Thermophysical properties
 
         //- Buoyancy force
@@ -135,9 +121,6 @@ protected:
         //- Mass flux field
         surfaceScalarField rhoPhi;
 
-        // Phase-1 volumetric flux
-        surfaceScalarField alphaPhi1;
-
 
     // Optional models
 
@@ -149,9 +132,6 @@ protected:
 
         tmp<volScalarField> rAU;
 
-        //- MULES Correction
-        tmp<surfaceScalarField> talphaPhi1Corr0;
-
         //- Pointer to the surface momentum field
         //  used to recreate the flux after mesh-change
         autoPtr<surfaceVectorField> Uf;
@@ -175,22 +155,19 @@ private:
     // Private Member Functions
 
         //- Set rDeltaT for LTS
-        virtual void setRDeltaT();
-
-        //- Correct the cached Courant numbers
-        void correctCoNum();
-
-        //- Solve for the phase-fractions
-        void alphaSolve(const dictionary& alphaControls);
-
-        //- Solve for the phase-fractions
-        void alphaPredictor();
+        void setRDeltaT();
 
 
 protected:
 
     // Protected Member Functions
 
+        //- Correct the cached Courant numbers
+        virtual void correctCoNum() = 0;
+
+        //- Adjust the rDeltaT in the vicinity of the interface
+        virtual void setInterfaceRDeltaT(volScalarField& rDeltaT) = 0;
+
         //- Calculate and print the continuity errors
         void continuityErrors();
 
@@ -201,16 +178,16 @@ protected:
         //  i.e. compressible or include phase-fraction sources
         virtual bool divergent() = 0;
 
-        //- Calculate the alpha equation sources
-        virtual void alphaSuSp
-        (
-            tmp<volScalarField::Internal>& Su,
-            tmp<volScalarField::Internal>& Sp
-        ) = 0;
-
         //- Return the momentum equation stress term
         virtual tmp<fvVectorMatrix> divDevTau(volVectorField& U) = 0;
 
+        //- Correct the interface properties following mesh-change
+        //  and phase-fraction update
+        virtual void correctInterface() = 0;
+
+        //- Return the interface surface tension force for the momentum equation
+        virtual tmp<surfaceScalarField> surfaceTensionForce() const = 0;
+
 
 public:
 
@@ -221,7 +198,7 @@ public:
     // Constructors
 
         //- Construct from region mesh
-        VoFSolver(fvMesh& mesh, autoPtr<twoPhaseMixture>);
+        VoFSolver(fvMesh& mesh, autoPtr<VoFMixture>);
 
         //- Disallow default bitwise copy construction
         VoFSolver(const VoFSolver&) = delete;
diff --git a/applications/solvers/modules/VoFSolver/alphaSuSp.H b/applications/solvers/modules/VoFSolver/alphaSuSp.H
deleted file mode 100644
index 2cee24cfb2..0000000000
--- a/applications/solvers/modules/VoFSolver/alphaSuSp.H
+++ /dev/null
@@ -1,19 +0,0 @@
-tmp<volScalarField> divU;
-tmp<volScalarField::Internal> Su;
-tmp<volScalarField::Internal> Sp;
-
-if (divergent())
-{
-    // Phase change alpha1 source
-    const fvScalarMatrix alphaSup(fvModels().source(alpha1));
-
-    Su = alphaSup.Su();
-    Sp = alphaSup.Sp();
-
-    divU =
-    (
-        mesh.moving()
-      ? fvc::div(phiCN() + mesh.phi())
-      : fvc::div(phiCN())
-    );
-}
diff --git a/applications/solvers/modules/VoFSolver/momentumPredictor.C b/applications/solvers/modules/VoFSolver/momentumPredictor.C
index 093b774479..b869031d9a 100644
--- a/applications/solvers/modules/VoFSolver/momentumPredictor.C
+++ b/applications/solvers/modules/VoFSolver/momentumPredictor.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -55,7 +55,7 @@ void Foam::solvers::VoFSolver::momentumPredictor()
             fvc::reconstruct
             (
                 (
-                    interface.surfaceTensionForce()
+                    surfaceTensionForce()
                   - buoyancy.ghf*fvc::snGrad(rho)
                   - fvc::snGrad(p_rgh)
                 ) * mesh.magSf()
diff --git a/applications/solvers/modules/VoFSolver/moveMesh.C b/applications/solvers/modules/VoFSolver/moveMesh.C
index 7be29fbab7..638308133e 100644
--- a/applications/solvers/modules/VoFSolver/moveMesh.C
+++ b/applications/solvers/modules/VoFSolver/moveMesh.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -101,7 +101,7 @@ bool Foam::solvers::VoFSolver::moveMesh()
 
             meshCourantNo();
 
-            interface.correct();
+            correctInterface();
 
             divU.clear();
 
diff --git a/applications/solvers/modules/VoFSolver/setRDeltaT.C b/applications/solvers/modules/VoFSolver/setRDeltaT.C
index b27ae2ca8c..fb87416236 100644
--- a/applications/solvers/modules/VoFSolver/setRDeltaT.C
+++ b/applications/solvers/modules/VoFSolver/setRDeltaT.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -24,9 +24,7 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "VoFSolver.H"
-#include "fvcSmooth.H"
 #include "fvcSurfaceIntegrate.H"
-#include "fvcAverage.H"
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
@@ -41,41 +39,6 @@ void Foam::solvers::VoFSolver::setRDeltaT()
         pimpleDict.lookupOrDefault<scalar>("maxCo", 0.9)
     );
 
-    const scalar maxAlphaCo
-    (
-        pimpleDict.lookupOrDefault<scalar>("maxAlphaCo", 0.2)
-    );
-
-    const scalar rDeltaTSmoothingCoeff
-    (
-        pimpleDict.lookupOrDefault<scalar>("rDeltaTSmoothingCoeff", 0.1)
-    );
-
-    const label nAlphaSpreadIter
-    (
-        pimpleDict.lookupOrDefault<label>("nAlphaSpreadIter", 1)
-    );
-
-    const scalar alphaSpreadDiff
-    (
-        pimpleDict.lookupOrDefault<scalar>("alphaSpreadDiff", 0.2)
-    );
-
-    const scalar alphaSpreadMax
-    (
-        pimpleDict.lookupOrDefault<scalar>("alphaSpreadMax", 0.99)
-    );
-
-    const scalar alphaSpreadMin
-    (
-        pimpleDict.lookupOrDefault<scalar>("alphaSpreadMin", 0.01)
-    );
-
-    const label nAlphaSweepIter
-    (
-        pimpleDict.lookupOrDefault<label>("nAlphaSweepIter", 5)
-    );
-
     const scalar maxDeltaT
     (
         pimpleDict.lookupOrDefault<scalar>("maxDeltaT", great)
@@ -101,56 +64,11 @@ void Foam::solvers::VoFSolver::setRDeltaT()
         )
     );
 
-    if (maxAlphaCo < maxCo)
-    {
-        // Further limit the reciprocal time-step
-        // in the vicinity of the interface
-
-        volScalarField alpha1Bar(fvc::average(alpha1));
-
-        rDeltaT.ref() = max
-        (
-            rDeltaT(),
-            pos0(alpha1Bar() - alphaSpreadMin)
-           *pos0(alphaSpreadMax - alpha1Bar())
-           *fvc::surfaceSum(mag(phi))()()
-           /((2*maxAlphaCo)*mesh.V())
-        );
-    }
-
-    // Update the boundary values of the reciprocal time-step
-    rDeltaT.correctBoundaryConditions();
-
     Info<< "Flow time scale min/max = "
         << gMin(1/rDeltaT.primitiveField())
         << ", " << gMax(1/rDeltaT.primitiveField()) << endl;
 
-    if (rDeltaTSmoothingCoeff < 1.0)
-    {
-        fvc::smooth(rDeltaT, rDeltaTSmoothingCoeff);
-    }
-
-    if (nAlphaSpreadIter > 0)
-    {
-        fvc::spread
-        (
-            rDeltaT,
-            alpha1,
-            nAlphaSpreadIter,
-            alphaSpreadDiff,
-            alphaSpreadMax,
-            alphaSpreadMin
-        );
-    }
-
-    if (nAlphaSweepIter > 0)
-    {
-        fvc::sweep(rDeltaT, alpha1, nAlphaSweepIter, alphaSpreadDiff);
-    }
-
-    Info<< "Smoothed flow time scale min/max = "
-        << gMin(1/rDeltaT.primitiveField())
-        << ", " << gMax(1/rDeltaT.primitiveField()) << endl;
+    setInterfaceRDeltaT(rDeltaT);
 
     // Limit rate of change of time scale
     // - reduce as much as required
diff --git a/applications/solvers/modules/compressibleVoF/Make/options b/applications/solvers/modules/compressibleVoF/Make/options
index ac7666b1b5..1fabb28405 100644
--- a/applications/solvers/modules/compressibleVoF/Make/options
+++ b/applications/solvers/modules/compressibleVoF/Make/options
@@ -1,4 +1,5 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/fluidSolver/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
@@ -16,7 +17,7 @@ EXE_INC = \
     -I$(LIB_SRC)/meshTools/lnInclude
 
 LIB_LIBS = \
-    -lVoFSolver \
+    -ltwoPhaseVoFSolver \
     -lphysicalProperties \
     -lfluidThermophysicalModels \
     -linterfaceCompression \
diff --git a/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.C b/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.C
index 2a0a0648d8..ebbe8e9697 100644
--- a/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.C
+++ b/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.C
@@ -40,7 +40,7 @@ Foam::compressibleTwoPhaseMixture::compressibleTwoPhaseMixture
     const fvMesh& mesh
 )
 :
-    twoPhaseMixture(mesh),
+    twoPhaseVoFMixture(mesh),
 
     totalInternalEnergy_
     (
@@ -205,7 +205,7 @@ Foam::tmp<Foam::scalarField> Foam::compressibleTwoPhaseMixture::nu
 
 bool Foam::compressibleTwoPhaseMixture::read()
 {
-    if (twoPhaseMixture::read())
+    if (twoPhaseVoFMixture::read())
     {
         totalInternalEnergy_ =
             lookupOrDefault<Switch>("totalInternalEnergy", true);
diff --git a/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.H b/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.H
index ce794a9d07..fc4126ee05 100644
--- a/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.H
+++ b/applications/solvers/modules/compressibleVoF/compressibleTwoPhaseMixture/compressibleTwoPhaseMixture.H
@@ -35,7 +35,7 @@ SourceFiles
 #ifndef compressibleTwoPhaseMixture_H
 #define compressibleTwoPhaseMixture_H
 
-#include "twoPhaseMixture.H"
+#include "twoPhaseVoFMixture.H"
 #include "compressibleTwoPhases.H"
 #include "rhoThermo.H"
 
@@ -50,7 +50,7 @@ namespace Foam
 
 class compressibleTwoPhaseMixture
 :
-    public twoPhaseMixture,
+    public twoPhaseVoFMixture,
     virtual public compressibleTwoPhases,
     public viscosity
 {
diff --git a/applications/solvers/modules/compressibleVoF/compressibleVoF.C b/applications/solvers/modules/compressibleVoF/compressibleVoF.C
index 61c8c2d395..0db13294ce 100644
--- a/applications/solvers/modules/compressibleVoF/compressibleVoF.C
+++ b/applications/solvers/modules/compressibleVoF/compressibleVoF.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -44,13 +44,13 @@ namespace solvers
 
 Foam::solvers::compressibleVoF::compressibleVoF(fvMesh& mesh)
 :
-    VoFSolver
+    twoPhaseVoFSolver
     (
         mesh,
-        autoPtr<twoPhaseMixture>(new compressibleTwoPhaseMixture(mesh))
+        autoPtr<twoPhaseVoFMixture>(new compressibleTwoPhaseMixture(mesh))
     ),
 
-    mixture(refCast<compressibleTwoPhaseMixture>(VoFSolver::mixture)),
+    mixture(refCast<compressibleTwoPhaseMixture>(twoPhaseVoFSolver::mixture)),
 
     p(mixture.p()),
 
@@ -142,7 +142,7 @@ Foam::solvers::compressibleVoF::~compressibleVoF()
 
 void Foam::solvers::compressibleVoF::prePredictor()
 {
-    VoFSolver::prePredictor();
+    twoPhaseVoFSolver::prePredictor();
 
     const volScalarField& rho1 = mixture.thermo1().rho();
     const volScalarField& rho2 = mixture.thermo2().rho();
@@ -178,7 +178,7 @@ void Foam::solvers::compressibleVoF::prePredictor()
 
 void Foam::solvers::compressibleVoF::momentumPredictor()
 {
-    VoFSolver::momentumPredictor();
+    twoPhaseVoFSolver::momentumPredictor();
 
     if (pimple.momentumPredictor())
     {
diff --git a/applications/solvers/modules/compressibleVoF/compressibleVoF.H b/applications/solvers/modules/compressibleVoF/compressibleVoF.H
index 13ee50af75..4bbdb51e3c 100644
--- a/applications/solvers/modules/compressibleVoF/compressibleVoF.H
+++ b/applications/solvers/modules/compressibleVoF/compressibleVoF.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -50,6 +50,7 @@ SourceFiles
 
 See also
     Foam::solvers::VoFSolver
+    Foam::solvers::twoPhaseVoFSolver
     Foam::solvers::incompressibleVoF
 
 \*---------------------------------------------------------------------------*/
@@ -57,7 +58,7 @@ See also
 #ifndef compressibleVoF_H
 #define compressibleVoF_H
 
-#include "VoFSolver.H"
+#include "twoPhaseVoFSolver.H"
 #include "compressibleTwoPhaseMixture.H"
 #include "compressibleInterPhaseTransportModel.H"
 #include "compressibleInterPhaseThermophysicalTransportModel.H"
@@ -78,7 +79,7 @@ namespace solvers
 
 class compressibleVoF
 :
-    public VoFSolver
+    public twoPhaseVoFSolver
 {
 
 protected:
diff --git a/applications/solvers/modules/compressibleVoF/fvModels/VoFCavitation/Make/options b/applications/solvers/modules/compressibleVoF/fvModels/VoFCavitation/Make/options
index 680a88833a..1c7071df46 100644
--- a/applications/solvers/modules/compressibleVoF/fvModels/VoFCavitation/Make/options
+++ b/applications/solvers/modules/compressibleVoF/fvModels/VoFCavitation/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/compressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/thermophysicalModels/basic/lnInclude \
diff --git a/applications/solvers/modules/compressibleVoF/fvModels/VoFClouds/Make/options b/applications/solvers/modules/compressibleVoF/fvModels/VoFClouds/Make/options
index 6842a4583f..d92adbc517 100644
--- a/applications/solvers/modules/compressibleVoF/fvModels/VoFClouds/Make/options
+++ b/applications/solvers/modules/compressibleVoF/fvModels/VoFClouds/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/compressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/thermophysicalModels/basic/lnInclude \
diff --git a/applications/solvers/modules/compressibleVoF/fvModels/VoFSolidificationMeltingSource/Make/options b/applications/solvers/modules/compressibleVoF/fvModels/VoFSolidificationMeltingSource/Make/options
index fe1ec97db0..6ec08e7b9d 100644
--- a/applications/solvers/modules/compressibleVoF/fvModels/VoFSolidificationMeltingSource/Make/options
+++ b/applications/solvers/modules/compressibleVoF/fvModels/VoFSolidificationMeltingSource/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/compressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/thermophysicalModels/basic/lnInclude \
diff --git a/applications/solvers/modules/compressibleVoF/fvModels/VoFSurfaceFilm/Make/options b/applications/solvers/modules/compressibleVoF/fvModels/VoFSurfaceFilm/Make/options
index e9d6b69ccb..1427b11ff2 100644
--- a/applications/solvers/modules/compressibleVoF/fvModels/VoFSurfaceFilm/Make/options
+++ b/applications/solvers/modules/compressibleVoF/fvModels/VoFSurfaceFilm/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/compressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/thermophysicalModels/basic/lnInclude \
diff --git a/applications/solvers/modules/compressibleVoF/fvModels/VoFTurbulenceDamping/Make/options b/applications/solvers/modules/compressibleVoF/fvModels/VoFTurbulenceDamping/Make/options
index 6208fc48a3..e095715a03 100644
--- a/applications/solvers/modules/compressibleVoF/fvModels/VoFTurbulenceDamping/Make/options
+++ b/applications/solvers/modules/compressibleVoF/fvModels/VoFTurbulenceDamping/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/compressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/thermophysicalModels/basic/lnInclude \
diff --git a/applications/solvers/modules/incompressibleVoF/Make/options b/applications/solvers/modules/incompressibleVoF/Make/options
index d851811d2b..c82c8b99f7 100644
--- a/applications/solvers/modules/incompressibleVoF/Make/options
+++ b/applications/solvers/modules/incompressibleVoF/Make/options
@@ -1,4 +1,5 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/fluidSolver/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
@@ -15,7 +16,7 @@ EXE_INC = \
     -I$(LIB_SRC)/sampling/lnInclude
 
 LIB_LIBS = \
-    -lVoFSolver \
+    -ltwoPhaseVoFSolver \
     -lphysicalProperties \
     -linterfaceCompression \
     -lincompressibleTwoPhases \
diff --git a/applications/solvers/modules/incompressibleVoF/fvModels/VoFCavitation/Make/options b/applications/solvers/modules/incompressibleVoF/fvModels/VoFCavitation/Make/options
index 8660e9eed8..5b8e052d3b 100644
--- a/applications/solvers/modules/incompressibleVoF/fvModels/VoFCavitation/Make/options
+++ b/applications/solvers/modules/incompressibleVoF/fvModels/VoFCavitation/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/incompressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/twoPhaseModels/twoPhaseMixture/lnInclude \
diff --git a/applications/solvers/modules/incompressibleVoF/fvModels/VoFTurbulenceDamping/Make/options b/applications/solvers/modules/incompressibleVoF/fvModels/VoFTurbulenceDamping/Make/options
index 2073519fcd..e1ea05faa6 100644
--- a/applications/solvers/modules/incompressibleVoF/fvModels/VoFTurbulenceDamping/Make/options
+++ b/applications/solvers/modules/incompressibleVoF/fvModels/VoFTurbulenceDamping/Make/options
@@ -1,4 +1,6 @@
 EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/twoPhaseVoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
     -I$(FOAM_SOLVERS)/modules/incompressibleVoF/lnInclude \
     -I$(LIB_SRC)/physicalProperties/lnInclude \
     -I$(LIB_SRC)/twoPhaseModels/twoPhaseMixture/lnInclude \
diff --git a/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.C b/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.C
index 801e58dad5..314a10455c 100644
--- a/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.C
+++ b/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.C
@@ -42,7 +42,7 @@ Foam::incompressibleTwoPhaseMixture::incompressibleTwoPhaseMixture
     const fvMesh& mesh
 )
 :
-    twoPhaseMixture(mesh),
+    twoPhaseVoFMixture(mesh),
 
     nuModel1_(viscosityModel::New(mesh, phase1Name())),
     nuModel2_(viscosityModel::New(mesh, phase2Name())),
@@ -138,7 +138,7 @@ Foam::incompressibleTwoPhaseMixture::nuf() const
 
 bool Foam::incompressibleTwoPhaseMixture::read()
 {
-    if (twoPhaseMixture::read())
+    if (twoPhaseVoFMixture::read())
     {
         nuModel1_->lookup("rho") >> rho1_;
         nuModel2_->lookup("rho") >> rho2_;
diff --git a/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.H b/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.H
index f0fc9bb558..0ec92345e1 100644
--- a/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.H
+++ b/applications/solvers/modules/incompressibleVoF/incompressibleTwoPhaseMixture/incompressibleTwoPhaseMixture.H
@@ -35,7 +35,7 @@ SourceFiles
 #ifndef incompressibleTwoPhaseMixture_H
 #define incompressibleTwoPhaseMixture_H
 
-#include "twoPhaseMixture.H"
+#include "twoPhaseVoFMixture.H"
 #include "incompressibleTwoPhases.H"
 #include "viscosityModel.H"
 
@@ -50,7 +50,7 @@ namespace Foam
 
 class incompressibleTwoPhaseMixture
 :
-    public twoPhaseMixture,
+    public twoPhaseVoFMixture,
     virtual public incompressibleTwoPhases,
     public viscosity
 {
diff --git a/applications/solvers/modules/incompressibleVoF/incompressibleVoF.C b/applications/solvers/modules/incompressibleVoF/incompressibleVoF.C
index 7a4a2e5bd5..f080ab9bbf 100644
--- a/applications/solvers/modules/incompressibleVoF/incompressibleVoF.C
+++ b/applications/solvers/modules/incompressibleVoF/incompressibleVoF.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -45,13 +45,13 @@ namespace solvers
 
 Foam::solvers::incompressibleVoF::incompressibleVoF(fvMesh& mesh)
 :
-    VoFSolver
+    twoPhaseVoFSolver
     (
         mesh,
-        autoPtr<twoPhaseMixture>(new incompressibleTwoPhaseMixture(mesh))
+        autoPtr<twoPhaseVoFMixture>(new incompressibleTwoPhaseMixture(mesh))
     ),
 
-    mixture(refCast<incompressibleTwoPhaseMixture>(VoFSolver::mixture)),
+    mixture(refCast<incompressibleTwoPhaseMixture>(twoPhaseVoFSolver::mixture)),
 
     p
     (
@@ -145,7 +145,7 @@ Foam::solvers::incompressibleVoF::~incompressibleVoF()
 
 void Foam::solvers::incompressibleVoF::prePredictor()
 {
-    VoFSolver::prePredictor();
+    twoPhaseVoFSolver::prePredictor();
 
     const dimensionedScalar& rho1 = mixture.rho1();
     const dimensionedScalar& rho2 = mixture.rho2();
diff --git a/applications/solvers/modules/incompressibleVoF/incompressibleVoF.H b/applications/solvers/modules/incompressibleVoF/incompressibleVoF.H
index 63a950dc77..5a51f3d5bd 100644
--- a/applications/solvers/modules/incompressibleVoF/incompressibleVoF.H
+++ b/applications/solvers/modules/incompressibleVoF/incompressibleVoF.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2022-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -50,6 +50,7 @@ SourceFiles
 
 See also
     Foam::solvers::VoFSolver
+    Foam::solvers::twoPhaseVoFSolver
     Foam::solvers::compressibleVoF
 
 \*---------------------------------------------------------------------------*/
@@ -57,7 +58,7 @@ See also
 #ifndef incompressibleVoF_H
 #define incompressibleVoF_H
 
-#include "VoFSolver.H"
+#include "twoPhaseVoFSolver.H"
 #include "incompressibleTwoPhaseMixture.H"
 #include "incompressibleInterPhaseTransportModel.H"
 
@@ -74,7 +75,7 @@ namespace solvers
 
 class incompressibleVoF
 :
-    public VoFSolver
+    public twoPhaseVoFSolver
 {
 
 protected:
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/Make/files b/applications/solvers/modules/twoPhaseVoFSolver/Make/files
new file mode 100644
index 0000000000..6e3783c4e1
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/Make/files
@@ -0,0 +1,6 @@
+twoPhaseVoFMixture/twoPhaseVoFMixture.C
+setInterfaceRDeltaT.C
+alphaPredictor.C
+twoPhaseVoFSolver.C
+
+LIB = $(FOAM_LIBBIN)/libtwoPhaseVoFSolver
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/Make/options b/applications/solvers/modules/twoPhaseVoFSolver/Make/options
new file mode 100644
index 0000000000..c9cd5e3c6e
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/Make/options
@@ -0,0 +1,24 @@
+EXE_INC = \
+    -I$(FOAM_SOLVERS)/modules/VoFSolver/lnInclude \
+    -I$(FOAM_SOLVERS)/modules/fluidSolver/lnInclude \
+    -I$(LIB_SRC)/physicalProperties/lnInclude \
+    -I$(LIB_SRC)/twoPhaseModels/VoF \
+    -I$(LIB_SRC)/twoPhaseModels/interfaceCompression/lnInclude \
+    -I$(LIB_SRC)/twoPhaseModels/interfaceProperties/lnInclude \
+    -I$(LIB_SRC)/twoPhaseModels/twoPhaseMixture/lnInclude \
+    -I$(LIB_SRC)/finiteVolume/lnInclude \
+    -I$(LIB_SRC)/meshTools/lnInclude \
+    -I$(LIB_SRC)/sampling/lnInclude
+
+LIB_LIBS = \
+    -lVoFSolver \
+    -lfluidSolver \
+    -lphysicalProperties \
+    -linterfaceCompression \
+    -linterfaceProperties \
+    -ltwoPhaseMixture \
+    -lfiniteVolume \
+    -lmeshTools \
+    -lfvModels \
+    -lfvConstraints \
+    -lsampling
diff --git a/applications/solvers/modules/VoFSolver/alphaPredictor.C b/applications/solvers/modules/twoPhaseVoFSolver/alphaPredictor.C
similarity index 97%
rename from applications/solvers/modules/VoFSolver/alphaPredictor.C
rename to applications/solvers/modules/twoPhaseVoFSolver/alphaPredictor.C
index f1c1d55f5e..78bd5b5ed7 100644
--- a/applications/solvers/modules/VoFSolver/alphaPredictor.C
+++ b/applications/solvers/modules/twoPhaseVoFSolver/alphaPredictor.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -23,7 +23,7 @@ License
 
 \*---------------------------------------------------------------------------*/
 
-#include "VoFSolver.H"
+#include "twoPhaseVoFSolver.H"
 #include "subCycle.H"
 #include "interfaceCompression.H"
 #include "CMULES.H"
@@ -33,7 +33,10 @@ License
 
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
-void Foam::solvers::VoFSolver::alphaSolve(const dictionary& alphaControls)
+void Foam::solvers::twoPhaseVoFSolver::alphaSolve
+(
+    const dictionary& alphaControls
+)
 {
     const label nAlphaSubCycles(alphaControls.lookup<label>("nAlphaSubCycles"));
 
@@ -339,7 +342,7 @@ void Foam::solvers::VoFSolver::alphaSolve(const dictionary& alphaControls)
 }
 
 
-void Foam::solvers::VoFSolver::alphaPredictor()
+void Foam::solvers::twoPhaseVoFSolver::alphaPredictor()
 {
     const dictionary& alphaControls = mesh.solution().solverDict(alpha1.name());
 
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/setInterfaceRDeltaT.C b/applications/solvers/modules/twoPhaseVoFSolver/setInterfaceRDeltaT.C
new file mode 100644
index 0000000000..25c9e34767
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/setInterfaceRDeltaT.C
@@ -0,0 +1,133 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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 "twoPhaseVoFSolver.H"
+#include "fvcSmooth.H"
+#include "fvcSurfaceIntegrate.H"
+#include "fvcAverage.H"
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::solvers::twoPhaseVoFSolver::setInterfaceRDeltaT
+(
+    volScalarField& rDeltaT
+)
+{
+    const dictionary& pimpleDict = pimple.dict();
+
+    const scalar maxCo
+    (
+        pimpleDict.lookupOrDefault<scalar>("maxCo", 0.9)
+    );
+
+    const scalar maxAlphaCo
+    (
+        pimpleDict.lookupOrDefault<scalar>("maxAlphaCo", 0.2)
+    );
+
+    const scalar rDeltaTSmoothingCoeff
+    (
+        pimpleDict.lookupOrDefault<scalar>("rDeltaTSmoothingCoeff", 0.1)
+    );
+
+    const label nAlphaSpreadIter
+    (
+        pimpleDict.lookupOrDefault<label>("nAlphaSpreadIter", 1)
+    );
+
+    const scalar alphaSpreadDiff
+    (
+        pimpleDict.lookupOrDefault<scalar>("alphaSpreadDiff", 0.2)
+    );
+
+    const scalar alphaSpreadMax
+    (
+        pimpleDict.lookupOrDefault<scalar>("alphaSpreadMax", 0.99)
+    );
+
+    const scalar alphaSpreadMin
+    (
+        pimpleDict.lookupOrDefault<scalar>("alphaSpreadMin", 0.01)
+    );
+
+    const label nAlphaSweepIter
+    (
+        pimpleDict.lookupOrDefault<label>("nAlphaSweepIter", 5)
+    );
+
+    if (maxAlphaCo < maxCo)
+    {
+        // Further limit the reciprocal time-step
+        // in the vicinity of the interface
+
+        volScalarField alpha1Bar(fvc::average(alpha1));
+
+        rDeltaT.ref() = max
+        (
+            rDeltaT(),
+            pos0(alpha1Bar() - alphaSpreadMin)
+           *pos0(alphaSpreadMax - alpha1Bar())
+           *fvc::surfaceSum(mag(phi))()()
+           /((2*maxAlphaCo)*mesh.V())
+        );
+    }
+
+    // Update the boundary values of the reciprocal time-step
+    rDeltaT.correctBoundaryConditions();
+
+    Info<< "Flow and interface time scale min/max = "
+        << gMin(1/rDeltaT.primitiveField())
+        << ", " << gMax(1/rDeltaT.primitiveField()) << endl;
+
+    if (rDeltaTSmoothingCoeff < 1.0)
+    {
+        fvc::smooth(rDeltaT, rDeltaTSmoothingCoeff);
+    }
+
+    if (nAlphaSpreadIter > 0)
+    {
+        fvc::spread
+        (
+            rDeltaT,
+            alpha1,
+            nAlphaSpreadIter,
+            alphaSpreadDiff,
+            alphaSpreadMax,
+            alphaSpreadMin
+        );
+    }
+
+    if (nAlphaSweepIter > 0)
+    {
+        fvc::sweep(rDeltaT, alpha1, nAlphaSweepIter, alphaSpreadDiff);
+    }
+
+    Info<< "Smoothed flow time scale min/max = "
+        << gMin(1/rDeltaT.primitiveField())
+        << ", " << gMax(1/rDeltaT.primitiveField()) << endl;
+}
+
+
+// ************************************************************************* //
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.C b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.C
new file mode 100644
index 0000000000..b2ce53f26f
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.C
@@ -0,0 +1,44 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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 "twoPhaseVoFMixture.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(twoPhaseVoFMixture, 0);
+}
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::twoPhaseVoFMixture::twoPhaseVoFMixture(const fvMesh& mesh)
+:
+    VoFMixture(mesh),
+    twoPhaseMixture(mesh)
+{}
+
+
+// ************************************************************************* //
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.H b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.H
new file mode 100644
index 0000000000..e427147002
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFMixture/twoPhaseVoFMixture.H
@@ -0,0 +1,93 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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::twoPhaseVoFMixture
+
+Description
+    Class to represent a VoF mixture
+
+SourceFiles
+    twoPhaseVoFMixture.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef twoPhaseVoFMixture_H
+#define twoPhaseVoFMixture_H
+
+#include "VoFMixture.H"
+#include "twoPhaseMixture.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                       Class twoPhaseVoFMixture Declaration
+\*---------------------------------------------------------------------------*/
+
+class twoPhaseVoFMixture
+:
+    public VoFMixture,
+    public twoPhaseMixture
+{
+
+public:
+
+    TypeName("twoPhaseVoFMixture");
+
+
+    // Constructors
+
+        //- Construct from components
+        twoPhaseVoFMixture(const fvMesh& mesh);
+
+
+    //- Destructor
+    virtual ~twoPhaseVoFMixture()
+    {}
+
+
+    // Member Functions
+
+        //- Return the mixture density
+        using twoPhaseMixture::rho;
+
+        //- Correct the mixture properties
+        using twoPhaseMixture::correct;
+
+        //- Read base phaseProperties dictionary
+        using twoPhaseMixture::read;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.C b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.C
new file mode 100644
index 0000000000..59d71cc23a
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.C
@@ -0,0 +1,164 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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 "twoPhaseVoFSolver.H"
+#include "localEulerDdtScheme.H"
+#include "CorrectPhi.H"
+#include "geometricZeroField.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace solvers
+{
+    defineTypeNameAndDebug(twoPhaseVoFSolver, 0);
+}
+}
+
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::solvers::twoPhaseVoFSolver::correctCoNum()
+{
+    VoFSolver::correctCoNum();
+
+    const scalarField sumPhi
+    (
+        interface.nearInterface()().primitiveField()
+       *fvc::surfaceSum(mag(phi))().primitiveField()
+    );
+
+    alphaCoNum = 0.5*gMax(sumPhi/mesh.V().field())*runTime.deltaTValue();
+
+    const scalar meanAlphaCoNum =
+        0.5*(gSum(sumPhi)/gSum(mesh.V().field()))*runTime.deltaTValue();
+
+    Info<< "Interface Courant Number mean: " << meanAlphaCoNum
+        << " max: " << alphaCoNum << endl;
+}
+
+
+// * * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * //
+
+void Foam::solvers::twoPhaseVoFSolver::correctInterface()
+{
+    return interface.correct();
+}
+
+
+Foam::tmp<Foam::surfaceScalarField>
+Foam::solvers::twoPhaseVoFSolver::surfaceTensionForce() const
+{
+    return interface.surfaceTensionForce();
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::solvers::twoPhaseVoFSolver::twoPhaseVoFSolver
+(
+    fvMesh& mesh,
+    autoPtr<twoPhaseVoFMixture> mixturePtr
+)
+:
+    VoFSolver(mesh, autoPtr<VoFMixture>(mixturePtr.ptr())),
+
+    mixture(refCast<twoPhaseVoFMixture>(VoFSolver::mixture)),
+
+    alpha1(mixture.alpha1()),
+    alpha2(mixture.alpha2()),
+
+    alphaRestart
+    (
+        typeIOobject<surfaceScalarField>
+        (
+            IOobject::groupName("alphaPhi", alpha1.group()),
+            runTime.name(),
+            mesh,
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ).headerOk()
+    ),
+
+    interface(mixture, alpha1, alpha2, U),
+
+    alphaPhi1
+    (
+        IOobject
+        (
+            IOobject::groupName("alphaPhi", alpha1.group()),
+            runTime.name(),
+            mesh,
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ),
+        phi*fvc::interpolate(alpha1)
+    )
+{
+    mesh.schemes().setFluxRequired(alpha1.name());
+
+    if (alphaRestart)
+    {
+        Info << "Restarting alpha" << endl;
+    }
+
+    if (transient())
+    {
+        correctCoNum();
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::solvers::twoPhaseVoFSolver::~twoPhaseVoFSolver()
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+void Foam::solvers::twoPhaseVoFSolver::preSolve()
+{
+    VoFSolver::preSolve();
+
+    // Do not apply previous time-step mesh compression flux
+    // if the mesh topology changed
+    if (mesh().topoChanged())
+    {
+        talphaPhi1Corr0.clear();
+    }
+}
+
+
+void Foam::solvers::twoPhaseVoFSolver::prePredictor()
+{
+    VoFSolver::prePredictor();
+
+    alphaPredictor();
+}
+
+
+// ************************************************************************* //
diff --git a/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.H b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.H
new file mode 100644
index 0000000000..c5eb2463b2
--- /dev/null
+++ b/applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.H
@@ -0,0 +1,195 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2023 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::solvers::twoPhaseVoFSolver
+
+Description
+    Solver module base-class for for 2 immiscible fluids using a VOF (volume
+    of fluid) phase-fraction based interface capturing approach, with optional
+    mesh motion and mesh topology changes including adaptive re-meshing.
+
+    The momentum and other fluid properties are of the "mixture" and a single
+    momentum equation is solved.
+
+    Either mixture or two-phase transport modelling may be selected.  In the
+    mixture approach a single laminar, RAS or LES model is selected to model the
+    momentum stress.  In the Euler-Euler two-phase approach separate laminar,
+    RAS or LES selected models are selected for each of the phases.
+
+    Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
+    pseudo-transient and steady simulations.
+
+    Optional fvModels and fvConstraints are provided to enhance the simulation
+    in many ways including adding various sources, Lagrangian
+    particles, surface film etc. and constraining or limiting the solution.
+
+SourceFiles
+    twoPhaseVoFSolver.C
+
+See also
+    Foam::solvers::fluidSolver
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef twoPhaseVoFSolver_H
+#define twoPhaseVoFSolver_H
+
+#include "VoFSolver.H"
+#include "twoPhaseVoFMixture.H"
+#include "interfaceProperties.H"
+#include "buoyancy.H"
+#include "pressureReference.H"
+#include "IOMRFZoneList.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace solvers
+{
+
+/*---------------------------------------------------------------------------*\
+                          Class twoPhaseVoFSolver Declaration
+\*---------------------------------------------------------------------------*/
+
+class twoPhaseVoFSolver
+:
+    public VoFSolver
+{
+
+protected:
+
+    // Phase properties
+
+        //- Reference to the twoPhaseVoFMixture
+        twoPhaseVoFMixture& mixture;
+
+        //- Reference to the phase1-fraction
+        volScalarField& alpha1;
+
+        //- Reference to the phase2-fraction
+        volScalarField& alpha2;
+
+        //- Switch indicating if this is a restart
+        bool alphaRestart;
+
+
+    // Interface properties
+
+        interfaceProperties interface;
+
+
+    // Kinematic properties
+
+        // Phase-1 volumetric flux
+        surfaceScalarField alphaPhi1;
+
+
+    // Cached temporary fields
+
+        //- MULES Correction
+        tmp<surfaceScalarField> talphaPhi1Corr0;
+
+
+private:
+
+    // Private Member Functions
+
+        //- Correct the cached Courant numbers
+        void correctCoNum();
+
+        //- Solve for the phase-fractions
+        void alphaSolve(const dictionary& alphaControls);
+
+        //- Solve for the phase-fractions
+        void alphaPredictor();
+
+
+protected:
+
+    // Protected Member Functions
+
+        //- Adjust the rDeltaT in the vicinity of the interface
+        virtual void setInterfaceRDeltaT(volScalarField& rDeltaT);
+
+        //- Calculate the alpha equation sources
+        virtual void alphaSuSp
+        (
+            tmp<volScalarField::Internal>& Su,
+            tmp<volScalarField::Internal>& Sp
+        ) = 0;
+
+        //- Correct the interface properties following mesh-change
+        //  and phase-fraction update
+        virtual void correctInterface();
+
+        //- Return the interface surface tension force for the momentum equation
+        virtual tmp<surfaceScalarField> surfaceTensionForce() const;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("twoPhaseVoFSolver");
+
+
+    // Constructors
+
+        //- Construct from region mesh
+        twoPhaseVoFSolver(fvMesh& mesh, autoPtr<twoPhaseVoFMixture>);
+
+        //- Disallow default bitwise copy construction
+        twoPhaseVoFSolver(const twoPhaseVoFSolver&) = delete;
+
+
+    //- Destructor
+    virtual ~twoPhaseVoFSolver();
+
+
+    // Member Functions
+
+        //- Called at the start of the time-step, before the PIMPLE loop
+        virtual void preSolve();
+
+        //- Called at the start of the PIMPLE loop
+        virtual void prePredictor();
+
+
+    // Member Operators
+
+        //- Disallow default bitwise assignment
+        void operator=(const twoPhaseVoFSolver&) = delete;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace solvers
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //