twoPhaseMixture: Add alpha2

src/transportModels/incompressible/incompressibleTwoPhaseMixture/twoPhaseMixture.C

@@ -54,7 +54,8 @@ Foam::twoPhaseMixture::twoPhaseMixture
 (
     const volVectorField& U,
     const surfaceScalarField& phi,
-    const word& alpha1Name
+    const word& alpha1Name,
+    const word& alpha2Name
 )
 :
     transportModel(U, phi),
@@ -102,6 +103,17 @@ Foam::twoPhaseMixture::twoPhaseMixture
         U_.mesh()
     ),
 
+    alpha2_
+    (
+        IOobject
+        (
+            found("phases") ? word("alpha" + phase2Name_) : alpha2Name,
+            U_.time().timeName(),
+            U_.db()
+        ),
+        1.0 - alpha1_
+    ),
+
     nu_
     (
         IOobject

src/transportModels/incompressible/incompressibleTwoPhaseMixture/twoPhaseMixture.H

@@ -70,6 +70,7 @@ protected:
         const surfaceScalarField& phi_;
 
         volScalarField alpha1_;
+        volScalarField alpha2_;
 
         volScalarField nu_;
 
@@ -89,7 +90,8 @@ public:
         (
             const volVectorField& U,
             const surfaceScalarField& phi,
-            const word& alpha1Name = "alpha1"
+            const word& alpha1Name = "alpha1",
+            const word& alpha2Name = "alpha2"
         );
 
 
@@ -122,6 +124,18 @@ public:
             return alpha1_;
         }
 
+        //- Return the phase-fraction of phase 2
+        const volScalarField& alpha2() const
+        {
+            return alpha2_;
+        }
+
+        //- Return the phase-fraction of phase 2
+        volScalarField& alpha2()
+        {
+            return alpha2_;
+        }
+
         //- Return const-access to phase1 viscosityModel
         const viscosityModel& nuModel1() const
         {