interDyMFoam, interPhaseChangeDyMFoam : Use 1/A from the previous time-step rather than 1 in the pcorr equation

This provides better convergence and consistency between p_rgh and pcorr

applications/solvers/multiphase/interFoam/interDyMFoam/correctPhi.H

@@ -37,7 +37,8 @@ if (mesh.changing())
         pcorrTypes
     );
 
-    dimensionedScalar rAUf("rAUf", dimTime/rho.dimensions(), 1.0);
+    // dimensionedScalar rAUf("rAUf", dimTime/rho.dimensions(), 1.0);
+    surfaceScalarField rAUf("rAUf", fvc::interpolate(rAU));
 
     while (pimple.correctNonOrthogonal())
     {

applications/solvers/multiphase/interFoam/interDyMFoam/interDyMFoam.C

@@ -57,6 +57,21 @@ int main(int argc, char *argv[])
     #include "createFields.H"
     #include "readTimeControls.H"
     #include "createPrghCorrTypes.H"
+
+    volScalarField rAU
+    (
+        IOobject
+        (
+            "rAU",
+            runTime.timeName(),
+            mesh,
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ),
+        mesh,
+        dimensionedScalar("rAUf", dimTime/rho.dimensions(), 1.0)
+    );
+
     #include "correctPhi.H"
     #include "createUf.H"
     #include "CourantNo.H"

applications/solvers/multiphase/interFoam/interDyMFoam/pEqn.H

@@ -1,5 +1,5 @@
 {
-    volScalarField rAU("rAU", 1.0/UEqn.A());
+    rAU = 1.0/UEqn.A();
     surfaceScalarField rAUf("rAUf", fvc::interpolate(rAU));
 
     volVectorField HbyA("HbyA", U);

applications/solvers/multiphase/interPhaseChangeFoam/interPhaseChangeDyMFoam/interPhaseChangeDyMFoam.C

@@ -67,6 +67,21 @@ int main(int argc, char *argv[])
     #include "createFields.H"
     #include "readTimeControls.H"
     #include "createPcorrTypes.H"
+
+    volScalarField rAU
+    (
+        IOobject
+        (
+            "rAU",
+            runTime.timeName(),
+            mesh,
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ),
+        mesh,
+        dimensionedScalar("rAUf", dimTime/rho.dimensions(), 1.0)
+    );
+
     #include "../interFoam/interDyMFoam/correctPhi.H"
     #include "createUf.H"
     #include "CourantNo.H"

applications/solvers/multiphase/interPhaseChangeFoam/interPhaseChangeDyMFoam/pEqn.H

@@ -1,5 +1,5 @@
 {
-    volScalarField rAU("rAU", 1.0/UEqn.A());
+    rAU = 1.0/UEqn.A();
     surfaceScalarField rAUf("rAUf", fvc::interpolate(rAU));
 
     volVectorField HbyA("HbyA", U);