multiphase: Improve the construction of rhoPhiSum

applications/solvers/multiphase/compressibleInterFoam/alphaEqnsSubCycle.H

@@ -9,7 +9,17 @@
     if (nAlphaSubCycles > 1)
     {
         dimensionedScalar totalDeltaT = runTime.deltaT();
-        surfaceScalarField rhoPhiSum(0.0*rhoPhi);
+        surfaceScalarField rhoPhiSum
+        (
+            IOobject
+            (
+                "rhoPhiSum",
+                runTime.timeName(),
+                mesh
+            ),
+            mesh,
+            dimensionedScalar("0", dimDensity, 0)
+        );
 
         for
         (

applications/solvers/multiphase/interFoam/LTSInterFoam/alphaEqnSubCycle.H

@@ -3,7 +3,17 @@
 if (nAlphaSubCycles > 1)
 {
     dimensionedScalar totalDeltaT = runTime.deltaT();
-    surfaceScalarField rhoPhiSum(0.0*rhoPhi);
+    surfaceScalarField rhoPhiSum
+    (
+        IOobject
+        (
+            "rhoPhiSum",
+            runTime.timeName(),
+            mesh
+        ),
+        mesh,
+        dimensionedScalar("0", dimDensity, 0)
+    );
 
     for
     (

applications/solvers/multiphase/interFoam/interMixingFoam/alphaEqnsSubCycle.H

@@ -2,8 +2,18 @@
 
 if (nAlphaSubCycles > 1)
 {
-    surfaceScalarField rhoPhiSum(0.0*rhoPhi);
     dimensionedScalar totalDeltaT = runTime.deltaT();
+    surfaceScalarField rhoPhiSum
+    (
+        IOobject
+        (
+            "rhoPhiSum",
+            runTime.timeName(),
+            mesh
+        ),
+        mesh,
+        dimensionedScalar("0", dimDensity, 0)
+    );
 
     for
     (

applications/solvers/multiphase/twoLiquidMixingFoam/alphaEqnSubCycle.H

@@ -3,7 +3,17 @@
 if (nAlphaSubCycles > 1)
 {
     dimensionedScalar totalDeltaT = runTime.deltaT();
-    surfaceScalarField rhoPhiSum(0.0*rhoPhi);
+    surfaceScalarField rhoPhiSum
+    (
+        IOobject
+        (
+            "rhoPhiSum",
+            runTime.timeName(),
+            mesh
+        ),
+        mesh,
+        dimensionedScalar("0", dimDensity, 0)
+    );
 
     for
     (