convergenceControl: Simplified convergence control for multi-region cases

In order to add convergence control to multi-region cases it is no longer
necessary to provide a residualControl entry in all region, convergence
specification can be provided for any sub-set of the region for which particular
residual levels should be met.

The tutorials/multiRegion/CHT/circuitBoardCooling case now has valid convergence
criteria to demonstrate this change.

tutorials/multiRegion/CHT/circuitBoardCooling/system/baffle3D/fvSolution

@@ -29,6 +29,11 @@ solvers
 PIMPLE
 {
     nNonOrthogonalCorrectors 0;
+
+    residualControl
+    {
+        e                 1e-4;
+    }
 }
 
 

tutorials/multiRegion/CHT/circuitBoardCooling/system/controlDict

@@ -27,7 +27,7 @@ startTime       0;
 
 stopAt          endTime;
 
-endTime         2500;
+endTime         5000;
 
 deltaT          1;
 

tutorials/multiRegion/CHT/circuitBoardCooling/system/fluid/fvSolution

@@ -37,14 +37,13 @@ solvers
 
 PIMPLE
 {
-    momentumPredictor no;
+    momentumPredictor yes;
     nNonOrthogonalCorrectors 0;
     pRefCell        0;
     pRefValue       0;
 
     residualControl
     {
-        p_rgh           1e-3;
         U               1e-4;
         h               1e-4;