rho?imple?Foam: Remove update of rho at beginning of pEqn to improve convergence

applications/solvers/compressible/rhoPimpleFoam/rhoPimplecFoam/pEqn.H

@@ -5,11 +5,10 @@ rho.relax();
 
 volScalarField rAU(1.0/UEqn().A());
 volScalarField rAtU(1.0/(1.0/rAU - UEqn().H1()));
-
 volVectorField HbyA("HbyA", U);
 HbyA = rAU*UEqn().H();
 
-if (pimple.nCorrPIMPLE() <= 1)
+if (pimple.nCorrPISO() <= 1)
 {
     UEqn.clear();
 }
@@ -26,6 +25,8 @@ if (pimple.transonic())
         )
     );
 
+    fvOptions.relativeFlux(fvc::interpolate(psi), phid);
+
     surfaceScalarField phic
     (
         "phic",
@@ -48,12 +49,9 @@ if (pimple.transonic())
             fvOptions(psi, p, rho.name())
         );
 
-        // Relax the pressure equation to maintain diagonal dominance
-        pEqn.relax();
-
         fvOptions.constrain(pEqn);
 
-        pEqn.solve();
+        pEqn.solve(mesh.solver(p.select(pimple.finalInnerIter())));
 
         if (pimple.finalNonOrthogonalIter())
         {
@@ -73,6 +71,8 @@ else
         )
     );
 
+    fvOptions.relativeFlux(fvc::interpolate(rho), phiHbyA);
+
     phiHbyA += fvc::interpolate(rho*(rAtU - rAU))*fvc::snGrad(p)*mesh.magSf();
     HbyA -= (rAU - rAtU)*fvc::grad(p);
 
@@ -91,7 +91,7 @@ else
 
         fvOptions.constrain(pEqn);
 
-        pEqn.solve();
+        pEqn.solve(mesh.solver(p.select(pimple.finalInnerIter())));
 
         if (pimple.finalNonOrthogonalIter())
         {

applications/solvers/compressible/rhoSimpleFoam/pEqn.H

 {
-    rho = thermo.rho();
-    rho = max(rho, rhoMin);
-    rho = min(rho, rhoMax);
-    rho.relax();
-
     volScalarField rAU(1.0/UEqn().A());
     volVectorField HbyA("HbyA", U);
     HbyA = rAU*UEqn().H();

applications/solvers/compressible/rhoSimpleFoam/rhoPorousSimpleFoam/pEqn.H

 {
-    rho = thermo.rho();
-    rho = max(rho, rhoMin);
-    rho = min(rho, rhoMax);
-    rho.relax();
-
     const volScalarField& psi = thermo.psi();
 
     volVectorField HbyA("HbyA", U);

applications/solvers/compressible/rhoSimpleFoam/rhoSimplecFoam/pEqn.H

-rho = thermo.rho();
-rho = max(rho, rhoMin);
-rho = min(rho, rhoMax);
-rho.relax();
-
 volScalarField rAU(1.0/UEqn().A());
 volScalarField rAtU(1.0/(1.0/rAU - UEqn().H1()));