chtMultiRegionFoam: SIMPLE operation and transonic switch

Multi-region PIMPLE controls have been applied to the chtMultiRegionFoam
solver, and a transonic option has been implemented.

The new PIMPLE controls let the solver operate SIMPLE mode. The
utilisation of library solution and convergence control functionality
has significantly reduced the amount of code in the solver. The
chtMultiRegionSimpleFoam solver has also been made obsolete, and has
therefore been removed.

A few changes will be necessary to convert an existing
chtMultiRegionSimpleFoam case to chtMultiRegionFoam. All the SIMPLE
sub-dictionaries in the system/<regions>/fvSolution will need to be
renamed PIMPLE. The system/fvSolution file will also need an empty
PIMPLE sub-dictionary. In addition, additional "<variable>Final" solver
and relaxation entries will be needed. For a steady case, adding a
wildcard ending, ".*", to the variable names should be sufficient.

Solution parameters appropriate for a steady case are shown below:

    solvers
    {
        "p_rgh.*"
        {
            solver           GAMG;
            tolerance        1e-7;
            relTol           0.01;
            smoother         DIC;
            maxIter          10;
        }

        "(U|h|e|k|epsilon).*"
        {
            solver           PBiCGStab;
            preconditioner   DILU;
            tolerance        1e-7;
            relTol           0.1;
        }
    }

    PIMPLE
    {
        // ...
    }

    relaxationFactors
    {
        fields
        {
            "p_rgh.*"       0.7;
        }
        equations
        {
            "U.*"           0.5;
            "(h|e).*"       0.3;
            "(k|epsilon).*" 0.2;
        }
    }

This work was supported by Fabian Buelow, at Evonik
Tobias Holzmann provided cases for testing the convergence controls

tutorials/heatTransfer/chtMultiRegionFoam/heatExchanger/system/air/fvSolution

@@ -10,55 +10,49 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    location    "system";
+    location    "system/air";
     object      fvSolution;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 solvers
 {
-    p_rgh
+    "p_rgh.*"
     {
         solver           GAMG;
         tolerance        1e-7;
         relTol           0.01;
-
         smoother         DIC;
-
-
         maxIter          100;
     }
 
-    "(U|h|e|k|epsilon)"
+    "(U|h|e|k|epsilon).*"
     {
-        solver          PBiCGStab;
-        preconditioner  DILU;
-        tolerance       1e-6;
-        relTol          0.1;
+        solver           PBiCGStab;
+        preconditioner   DILU;
+        tolerance        1e-6;
+        relTol           0.1;
     }
 }
 
-SIMPLE
+PIMPLE
 {
     nNonOrthogonalCorrectors 0;
-    rhoMax          2;
-    rhoMin          1;
 }
 
-
 relaxationFactors
 {
     fields
     {
-        rho             1;
-        p_rgh           0.7;
+        "rho.*"         1;
+        "p_rgh.*"       0.7;
     }
     equations
     {
-        U               0.3;
-        "(h|e)"         0.3;
-        k               0.3;
-        epsilon         0.3;
+        "U.*"           0.3;
+        "(h|e).*"       0.3;
+        "k.*"           0.3;
+        "epsilon.*"     0.3;
     }
 }
 

tutorials/heatTransfer/chtMultiRegionFoam/heatExchanger/system/controlDict

@@ -15,7 +15,7 @@ FoamFile
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-application     chtMultiRegionSimpleFoam;
+application     chtMultiRegionFoam;
 
 startFrom       latestTime;
 

tutorials/heatTransfer/chtMultiRegionFoam/heatExchanger/system/porous/fvSolution

@@ -10,25 +10,23 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
+    location    "system/porous";
     object      fvSolution;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 solvers
 {
-    p_rgh
+    "p_rgh.*"
     {
         solver           GAMG;
         tolerance        1e-7;
         relTol           0.01;
-
         smoother         DIC;
-
-
         maxIter          10;
     }
 
-    "(U|h|e|k|epsilon)"
+    "(U|h|e|k|epsilon).*"
     {
         solver           PBiCGStab;
         preconditioner   DILU;
@@ -37,26 +35,24 @@ solvers
     }
 }
 
-SIMPLE
+PIMPLE
 {
     nNonOrthogonalCorrectors 0;
-    rhoMax          1100;
-    rhoMin          900;
 }
 
 relaxationFactors
 {
     fields
     {
-        rho             1;
-        p_rgh           0.7;
+        "rho.*"         1;
+        "p_rgh.*"       0.7;
     }
     equations
     {
-        U               0.3;
-        "(h|e)"         0.3;
-        k               0.3;
-        epsilon         0.3;
+        "U.*"           0.3;
+        "(h|e).*"       0.3;
+        "k.*"           0.3;
+        "epsilon.*"     0.3;
     }
 }
 

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/bottomAir/fvSolution

@@ -16,15 +16,7 @@ FoamFile
 
 solvers
 {
-    rho
-    {
-        solver          PCG
-        preconditioner  DIC;
-        tolerance       1e-7;
-        relTol          0;
-    }
-
-    p_rgh
+    "p_rgh.*"
     {
         solver           GAMG;
         tolerance        1e-7;
@@ -34,47 +26,36 @@ solvers
 
     }
 
-    "(U|h|k|epsilon|G|Ii)"
+    "(U|h|k|epsilon).*"
     {
         solver           PBiCGStab;
         preconditioner   DILU;
         tolerance        1e-7;
         relTol           0.1;
     }
-
-    G
-    {
-        $p_rgh;
-        tolerance       1e-05;
-        relTol          0.1;
-    }
 }
 
-SIMPLE
+PIMPLE
 {
     momentumPredictor yes;
     nNonOrthogonalCorrectors 0;
     pRefCell        0;
     pRefValue       100000;
-    rhoMin          0.2;
-    rhoMax          2;
 }
 
 relaxationFactors
 {
     fields
     {
-        rho             1.0;
-        p_rgh           0.7;
+        "rho.*"         1.0;
+        "p_rgh.*"       0.7;
     }
     equations
     {
-        U               0.3;
-        h               0.7;
-        "(k|epsilon|omega)" 0.7;
-        G               0.7;
-        "ILambda.*"     0.7;
-        qr              0.7;
+        "U.*"            0.3;
+        "h.*"            0.7;
+        "(k|epsilon|omega).*" 0.7;
+        "qr.*"          0.7;
     }
 }
 

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/controlDict

@@ -15,7 +15,7 @@ FoamFile
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-application     chtMultiRegionSimpleFoam;
+application     chtMultiRegionFoam;
 
 startFrom       startTime;
 

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/fvSolution

@@ -14,4 +14,9 @@ FoamFile
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+PIMPLE
+{
+}
+
+
 // ************************************************************************* //

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/heater/fvSolution

@@ -16,7 +16,7 @@ FoamFile
 
 solvers
 {
-    h
+    "h.*"
     {
         solver           PCG;
         preconditioner   DIC;
@@ -25,7 +25,7 @@ solvers
     }
 }
 
-SIMPLE
+PIMPLE
 {
     nNonOrthogonalCorrectors 0;
 }
@@ -34,7 +34,7 @@ relaxationFactors
 {
     equations
     {
-        h               0.7;
+        "h.*"           0.7;
     }
 }
 

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/leftSolid/fvSolution

@@ -16,7 +16,7 @@ FoamFile
 
 solvers
 {
-    h
+    "h.*"
     {
         solver           PCG;
         preconditioner   DIC;
@@ -25,7 +25,7 @@ solvers
     }
 }
 
-SIMPLE
+PIMPLE
 {
     nNonOrthogonalCorrectors 0;
 }
@@ -34,7 +34,7 @@ relaxationFactors
 {
     equations
     {
-        h               0.7;
+        "h.*"           0.7;
     }
 }
 

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/rightSolid/fvSolution

@@ -16,7 +16,7 @@ FoamFile
 
 solvers
 {
-    h
+    "h.*"
     {
         solver           PCG;
         preconditioner   DIC;
@@ -25,7 +25,7 @@ solvers
     }
 }
 
-SIMPLE
+PIMPLE
 {
     nNonOrthogonalCorrectors 0;
 }
@@ -34,7 +34,7 @@ relaxationFactors
 {
     equations
     {
-        h               0.7;
+        "h.*"           0.7;
     }
 }
 

tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeaterRadiation/system/topAir/fvSolution

@@ -16,15 +16,7 @@ FoamFile
 
 solvers
 {
-    rho
-    {
-        solver          PCG
-        preconditioner  DIC;
-        tolerance       1e-7;
-        relTol          0;
-    }
-
-    p_rgh
+    "p_rgh.*"
     {
         solver           GAMG;
         tolerance        1e-7;
@@ -34,47 +26,36 @@ solvers
 
     }
 
-    "(U|h|k|epsilon|G|Ii)"
+    "(U|h|k|epsilon).*"
     {
         solver           PBiCGStab;
         preconditioner   DILU;
         tolerance        1e-7;
         relTol           0.1;
     }
-
-    G
-    {
-        $p_rgh;
-        tolerance       1e-05;
-        relTol          0.1;
-    }
 }
 
-SIMPLE
+PIMPLE
 {
     momentumPredictor yes;
     nNonOrthogonalCorrectors 0;
     pRefCell        0;
     pRefValue       100000;
-    rhoMin          0.2;
-    rhoMax          2;
 }
 
 relaxationFactors
 {
     fields
     {
-        rho             1.0;
-        p_rgh           0.7;
+        "rho.*"         1.0;
+        "p_rgh.*"       0.7;
     }
     equations
     {
-        U               0.3;
-        h               0.7;
-        "(k|epsilon|omega)" 0.7;
-        G               0.7;
-        "ILambda.*"     0.7;
-        qr              0.7;
+        "U.*"           0.3;
+        "h.*"           0.7;
+        "(k|epsilon|omega).*" 0.7;
+        "qr.*"          0.7;
     }
 }