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();
+    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();
+    p.correctBoundaryConditions();
+    rho = thermo.rho();
+}
 
 if (!pimple.transonic())
 {

applications/solvers/compressible/rhoSimpleFoam/pEqn.H

@@ -1,109 +1,110 @@
+volScalarField rAU(1.0/UEqn.A());
+surfaceScalarField rhorAUf("rhorAUf", fvc::interpolate(rho*rAU));
+volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
+tUEqn.clear();
+
+bool closedVolume = false;
+
+surfaceScalarField phiHbyA("phiHbyA", fvc::interpolate(rho)*fvc::flux(HbyA));
+MRF.makeRelative(fvc::interpolate(rho), phiHbyA);
+
+// Update the pressure BCs to ensure flux consistency
+constrainPressure(p, rho, U, phiHbyA, rhorAUf, MRF);
+
+if (simple.transonic())
 {
-    volScalarField rAU(1.0/UEqn.A());
+    surfaceScalarField phid
-    surfaceScalarField rhorAUf("rhorAUf", fvc::interpolate(rho*rAU));
+    (
-    volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
+        "phid",
-    tUEqn.clear();
+        (fvc::interpolate(psi)/fvc::interpolate(rho))*phiHbyA
+    );
 
-    bool closedVolume = false;
+    phiHbyA -= fvc::interpolate(psi*p)*phiHbyA/fvc::interpolate(rho);
 
-    surfaceScalarField phiHbyA("phiHbyA", fvc::flux(rho*HbyA));
+    while (simple.correctNonOrthogonal())
-    MRF.makeRelative(fvc::interpolate(rho), phiHbyA);
-
-    // Update the pressure BCs to ensure flux consistency
-    constrainPressure(p, rho, U, phiHbyA, rhorAUf, MRF);
-
-    if (simple.transonic())
     {
-        surfaceScalarField phid
+        fvScalarMatrix pEqn
         (
-            "phid",
+            fvc::div(phiHbyA)
-            (fvc::interpolate(psi)/fvc::interpolate(rho))*phiHbyA
+          + fvm::div(phid, p)
+          - fvm::laplacian(rhorAUf, p)
+          ==
+            fvOptions(psi, p, rho.name())
         );
-        phiHbyA -= fvc::interpolate(p)*phid;
 
-        while (simple.correctNonOrthogonal())
+        // Relax the pressure equation to ensure diagonal-dominance
+        pEqn.relax();
+
+        pEqn.setReference
+        (
+            pressureControl.refCell(),
+            pressureControl.refValue()
+        );
+
+        pEqn.solve();
+
+        if (simple.finalNonOrthogonalIter())
         {
-            fvScalarMatrix pEqn
+            phi = phiHbyA + pEqn.flux();
-            (
-                fvc::div(phiHbyA)
-              + fvm::div(phid, p)
-              - fvm::laplacian(rhorAUf, p)
-              ==
-                fvOptions(psi, p, rho.name())
-            );
-
-            // Relax the pressure equation to ensure diagonal-dominance
-            pEqn.relax();
-
-            pEqn.setReference
-            (
-                pressureControl.refCell(),
-                pressureControl.refValue()
-            );
-
-            pEqn.solve();
-
-            if (simple.finalNonOrthogonalIter())
-            {
-                phi = phiHbyA + pEqn.flux();
-            }
         }
     }
-    else
+}
-    {
+else
-        closedVolume = adjustPhi(phiHbyA, U, p);
+{
-
+    closedVolume = adjustPhi(phiHbyA, U, p);
-        while (simple.correctNonOrthogonal())
+
-        {
+    while (simple.correctNonOrthogonal())
-            fvScalarMatrix pEqn
+    {
-            (
+        fvScalarMatrix pEqn
-                fvc::div(phiHbyA)
+        (
-              - fvm::laplacian(rhorAUf, p)
+            fvc::div(phiHbyA)
-              ==
+          - fvm::laplacian(rhorAUf, p)
-                fvOptions(psi, p, rho.name())
+          ==
-            );
+            fvOptions(psi, p, rho.name())
-
+        );
-            pEqn.setReference
+
-            (
+        pEqn.setReference
-                pressureControl.refCell(),
+        (
-                pressureControl.refValue()
+            pressureControl.refCell(),
-            );
+            pressureControl.refValue()
-
+        );
-            pEqn.solve();
+
-
+        pEqn.solve();
-            if (simple.finalNonOrthogonalIter())
+
-            {
+        if (simple.finalNonOrthogonalIter())
-                phi = phiHbyA + pEqn.flux();
+        {
-            }
+            phi = phiHbyA + pEqn.flux();
-        }
+        }
-    }
+    }
-
+}
-
+
-    #include "incompressible/continuityErrs.H"
+#include "incompressible/continuityErrs.H"
-
+
-    // Explicitly relax pressure for momentum corrector
+// Explicitly relax pressure for momentum corrector
-    p.relax();
+p.relax();
-
+
-    U = HbyA - rAU*fvc::grad(p);
+U = HbyA - rAU*fvc::grad(p);
-    U.correctBoundaryConditions();
+U.correctBoundaryConditions();
-    fvOptions.correct(U);
+fvOptions.correct(U);
-
+
-    pressureControl.limit(p);
+bool pLimited = pressureControl.limit(p);
-
+
-    // For closed-volume cases adjust the pressure and density levels
+// For closed-volume cases adjust the pressure and density levels
-    // to obey overall mass continuity
+// to obey overall mass continuity
-    if (closedVolume)
+if (closedVolume)
-    {
+{
-        p += (initialMass - fvc::domainIntegrate(psi*p))
+    p += (initialMass - fvc::domainIntegrate(psi*p))
-            /fvc::domainIntegrate(psi);
+        /fvc::domainIntegrate(psi);
-    }
+}
-
+
-    p.correctBoundaryConditions();
+if (pLimited || closedVolume)
-
+{
-    rho = thermo.rho();
+    p.correctBoundaryConditions();
-
+}
-    if (!simple.transonic())
+
-    {
+rho = thermo.rho();
-        rho.relax();
+
-    }
+if (!simple.transonic())
+{
+    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);
 }
 
-p.correctBoundaryConditions();
+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;
 
-    p = max(p, pMin_);
+    if (pMax > pMax_.value() || pMin < pMin_.value())
-    p = min(p, pMax_);
+    {
+        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;
 };