rhoPimpleFoam: Updated transonic option to be consistent with sonicFoam

Improves stability on start-up and allows running at slightly larger time-steps.

applications/solvers/compressible/rhoPimpleFoam/pEqn.H

@@ -1,3 +1,5 @@
+rho = thermo.rho();
+
 volScalarField rAU(1.0/UEqn.A());
 surfaceScalarField rhorAUf("rhorAUf", fvc::interpolate(rho*rAU));
 volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
@@ -10,7 +12,7 @@ if (pimple.nCorrPISO() <= 1)
 surfaceScalarField phiHbyA
 (
     "phiHbyA",
-    fvc::flux(rho*HbyA)
+    fvc::interpolate(rho)*fvc::flux(HbyA)
   + rhorAUf*fvc::ddtCorr(rho, U, phi)
 );
 
@@ -26,7 +28,8 @@ if (pimple.transonic())
         "phid",
         (fvc::interpolate(psi)/fvc::interpolate(rho))*phiHbyA
     );
-    phiHbyA -= fvc::interpolate(p)*phid;
+
+    phiHbyA -= fvc::interpolate(psi*p)*phiHbyA/fvc::interpolate(rho);
 
     while (pimple.correctNonOrthogonal())
     {
@@ -84,9 +87,11 @@ U.correctBoundaryConditions();
 fvOptions.correct(U);
 K = 0.5*magSqr(U);
 
-pressureControl.limit(p);
+if (pressureControl.limit(p))
+{
     p.correctBoundaryConditions();
     rho = thermo.rho();
+}
 
 if (!pimple.transonic())
 {

applications/solvers/compressible/rhoPimpleFoam/pcEqn.H

@@ -1,3 +1,5 @@
+rho = thermo.rho();
+
 volScalarField rAU(1.0/UEqn.A());
 volScalarField rAtU(1.0/(1.0/rAU - UEqn.H1()));
 volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
@@ -11,7 +13,7 @@ surfaceScalarField phiHbyA
 (
     "phiHbyA",
     (
-        fvc::flux(rho*HbyA)
+        fvc::interpolate(rho)*fvc::flux(HbyA)
       + fvc::interpolate(rho*rAU)*fvc::ddtCorr(rho, U, phi)
     )
 );
@@ -33,7 +35,7 @@ if (pimple.transonic())
 
     phiHbyA +=
         fvc::interpolate(rho*(rAtU - rAU))*fvc::snGrad(p)*mesh.magSf()
-      - fvc::interpolate(p)*phid;
+      - fvc::interpolate(psi*p)*phiHbyA/fvc::interpolate(rho);
 
     HbyA -= (rAU - rAtU)*fvc::grad(p);
 
@@ -96,9 +98,11 @@ U.correctBoundaryConditions();
 fvOptions.correct(U);
 K = 0.5*magSqr(U);
 
-pressureControl.limit(p);
+if (pressureControl.limit(p))
+{
     p.correctBoundaryConditions();
     rho = thermo.rho();
+}
 
 if (!pimple.transonic())
 {

applications/solvers/compressible/rhoSimpleFoam/pEqn.H

@@ -1,4 +1,3 @@
-{
 volScalarField rAU(1.0/UEqn.A());
 surfaceScalarField rhorAUf("rhorAUf", fvc::interpolate(rho*rAU));
 volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
@@ -6,7 +5,7 @@
 
 bool closedVolume = false;
 
-    surfaceScalarField phiHbyA("phiHbyA", fvc::flux(rho*HbyA));
+surfaceScalarField phiHbyA("phiHbyA", fvc::interpolate(rho)*fvc::flux(HbyA));
 MRF.makeRelative(fvc::interpolate(rho), phiHbyA);
 
 // Update the pressure BCs to ensure flux consistency
@@ -19,7 +18,8 @@
         "phid",
         (fvc::interpolate(psi)/fvc::interpolate(rho))*phiHbyA
     );
-        phiHbyA -= fvc::interpolate(p)*phid;
+
+    phiHbyA -= fvc::interpolate(psi*p)*phiHbyA/fvc::interpolate(rho);
 
     while (simple.correctNonOrthogonal())
     {
@@ -78,7 +78,6 @@
     }
 }
 
-
 #include "incompressible/continuityErrs.H"
 
 // Explicitly relax pressure for momentum corrector
@@ -88,7 +87,7 @@
 U.correctBoundaryConditions();
 fvOptions.correct(U);
 
-    pressureControl.limit(p);
+bool pLimited = pressureControl.limit(p);
 
 // For closed-volume cases adjust the pressure and density levels
 // to obey overall mass continuity
@@ -98,7 +97,10 @@
         /fvc::domainIntegrate(psi);
 }
 
+if (pLimited || closedVolume)
+{
     p.correctBoundaryConditions();
+}
 
 rho = thermo.rho();
 
@@ -106,4 +108,3 @@
 {
     rho.relax();
 }
-}

applications/solvers/compressible/rhoSimpleFoam/pcEqn.H

@@ -1,3 +1,5 @@
+rho = thermo.rho();
+
 volScalarField rAU(1.0/UEqn.A());
 volScalarField rAtU(1.0/(1.0/rAU - UEqn.H1()));
 volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
@@ -5,7 +7,7 @@ tUEqn.clear();
 
 bool closedVolume = false;
 
-surfaceScalarField phiHbyA("phiHbyA", fvc::flux(rho*HbyA));
+surfaceScalarField phiHbyA("phiHbyA", fvc::interpolate(rho)*fvc::flux(HbyA));
 MRF.makeRelative(fvc::interpolate(rho), phiHbyA);
 
 volScalarField rhorAtU("rhorAtU", rho*rAtU);
@@ -23,7 +25,7 @@ if (simple.transonic())
 
     phiHbyA +=
         fvc::interpolate(rho*(rAtU - rAU))*fvc::snGrad(p)*mesh.magSf()
-      - fvc::interpolate(p)*phid;
+      - fvc::interpolate(psi*p)*phiHbyA/fvc::interpolate(rho);
 
     HbyA -= (rAU - rAtU)*fvc::grad(p);
 
@@ -98,7 +100,7 @@ U = HbyA - rAtU*fvc::grad(p);
 U.correctBoundaryConditions();
 fvOptions.correct(U);
 
-pressureControl.limit(p);
+bool pLimited = pressureControl.limit(p);
 
 // For closed-volume cases adjust the pressure and density levels
 // to obey overall mass continuity
@@ -108,9 +110,11 @@ if (closedVolume)
         /fvc::domainIntegrate(psi);
 }
 
+if (pLimited || closedVolume)
+{
     p.correctBoundaryConditions();
+}
 
-// Recalculate density from the relaxed pressure
 rho = thermo.rho();
 
 if (!simple.transonic())

src/finiteVolume/cfdTools/general/pressureControl/pressureControl.C

@@ -207,14 +207,24 @@ Foam::pressureControl::pressureControl
 
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
-void Foam::pressureControl::limit(volScalarField& p) const
+bool Foam::pressureControl::limit(volScalarField& p) const
 {
-    Info<< "pressureControl: p max/min "
+    scalar pMax = max(p).value();
-        << max(p).value() << " "
+    scalar pMin = min(p).value();
-        << min(p).value() << endl;
+
+    if (pMax > pMax_.value() || pMin < pMin_.value())
+    {
+        Info<< "pressureControl: p max/min " << pMax << " " << pMin << endl;
 
         p = max(p, pMin_);
         p = min(p, pMax_);
+
+        return true;
+    }
+    else
+    {
+        return false;
+    }
 }
 
 

src/finiteVolume/cfdTools/general/pressureControl/pressureControl.H

@@ -89,8 +89,8 @@ public:
         //- Return the pressure reference level
         inline scalar refValue() const;
 
-        //- Limit the pressure
+        //- Limit the pressure if necessary and return true if so
-        void limit(volScalarField& p) const;
+        bool limit(volScalarField& p) const;
 };