solvers::incompressibleDriftFlux: New solver module for two-phase flow with drift-flux

executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations.  Replaces driftFluxFoam and all the corresponding
tutorials have been updated and moved to
tutorials/modules/incompressibleDriftFlux.

Class
    Foam::solvers::incompressibleDriftFlux

Description
    Solver module for 2 incompressible fluids using the mixture approach with
    the drift-flux approximation for relative motion of the phases, 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 with mixture transport modelling in which a
    single laminar, RAS or LES model is selected to model the momentum stress.

    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
    incompressibleDriftFlux.C

See also
    Foam::solvers::VoFSolver
    Foam::solvers::twoPhaseVoFSolver
    Foam::solvers::compressibleVoF

applications/solvers/modules/twoPhaseVoFSolver/alphaPredictor.C

@@ -33,6 +33,41 @@ License
 
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
+Foam::tmp<Foam::surfaceScalarField> Foam::solvers::twoPhaseVoFSolver::alphaPhi
+(
+    const surfaceScalarField& phi,
+    const volScalarField& alpha,
+    const dictionary& alphaControls
+)
+{
+    const word alphaScheme(mesh.schemes().div(divAlphaName)[1].wordToken());
+
+    ITstream compressionScheme
+    (
+        compressionSchemes.found(alphaScheme)
+      ? mesh.schemes().div(divAlphaName)
+      : ITstream
+        (
+            divAlphaName,
+            tokenList
+            {
+                word("Gauss"),
+                word("interfaceCompression"),
+                alphaScheme,
+                alphaControls.lookup<scalar>("cAlpha")
+            }
+        )
+    );
+
+    return fvc::flux
+    (
+        phi,
+        alpha,
+        compressionScheme
+    );
+}
+
+
 void Foam::solvers::twoPhaseVoFSolver::alphaSolve
 (
     const dictionary& alphaControls
@@ -55,25 +90,6 @@ void Foam::solvers::twoPhaseVoFSolver::alphaSolve
         alphaControls.lookupOrDefault<Switch>("alphaApplyPrevCorr", false)
     );
 
-    const word alphaScheme(mesh.schemes().div(divAlphaName)[1].wordToken());
-
-    ITstream compressionScheme
-    (
-        compressionSchemes.found(alphaScheme)
-      ? mesh.schemes().div(divAlphaName)
-      : ITstream
-        (
-            divAlphaName,
-            tokenList
-            {
-                word("Gauss"),
-                word("interfaceCompression"),
-                alphaScheme,
-                alphaControls.lookup<scalar>("cAlpha")
-            }
-        )
-    );
-
 
     // Set the off-centering coefficient according to ddt scheme
     scalar ocCoeff = 0;
@@ -219,11 +235,11 @@ void Foam::solvers::twoPhaseVoFSolver::alphaSolve
         // Split operator
         tmp<surfaceScalarField> talphaPhi1Un
         (
-            fvc::flux
+            alphaPhi
             (
                 phiCN(),
                 (cnCoeff*alpha1 + (1.0 - cnCoeff)*alpha1.oldTime())(),
-                compressionScheme.rewind()
+                alphaControls
             )
         );
 
@@ -399,8 +415,6 @@ void Foam::solvers::twoPhaseVoFSolver::alphaPredictor()
     {
         alphaSolve(alphaControls);
     }
-
-    mixture.correct();
 }
 
 

applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.C

@@ -155,8 +155,8 @@ void Foam::solvers::twoPhaseVoFSolver::preSolve()
 void Foam::solvers::twoPhaseVoFSolver::prePredictor()
 {
     VoFSolver::prePredictor();
-
     alphaPredictor();
+    mixture.correct();
 }
 
 

applications/solvers/modules/twoPhaseVoFSolver/twoPhaseVoFSolver.H

@@ -119,14 +119,21 @@ private:
         //- Solve for the phase-fractions
         void alphaSolve(const dictionary& alphaControls);
 
-        //- Solve for the phase-fractions
-        void alphaPredictor();
-
 
 protected:
 
     // Protected Member Functions
 
+        virtual tmp<surfaceScalarField> alphaPhi
+        (
+            const surfaceScalarField& phi,
+            const volScalarField& alpha,
+            const dictionary& alphaControls
+        );
+
+        //- Solve for the phase-fractions
+        void alphaPredictor();
+
         //- Adjust the rDeltaT in the vicinity of the interface
         virtual void setInterfaceRDeltaT(volScalarField& rDeltaT);