solver: Make time-step fractional increase available externally

applications/solvers/foamMultiRun/setDeltaT.C

@@ -74,7 +74,14 @@ void Foam::adjustDeltaT(Time& runTime, const PtrList<solver>& solvers)
 
         if (transient && deltaT < rootVGreat)
         {
-            runTime.setDeltaT(min(1.2*runTime.deltaTValue(), deltaT));
+            runTime.setDeltaT
+            (
+                min
+                (
+                    solver::maxIncreaseDeltaT*runTime.deltaTValue(),
+                    deltaT
+                )
+            );
             Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
         }
     }

applications/solvers/foamRun/setDeltaT.C

@@ -52,7 +52,14 @@ void Foam::adjustDeltaT(Time& runTime, const solver& solver)
      && solver.maxDeltaT() < rootVGreat
     )
     {
-        runTime.setDeltaT(min(1.2*runTime.deltaTValue(), solver.maxDeltaT()));
+        runTime.setDeltaT
+        (
+            min
+            (
+                solver::maxIncreaseDeltaT*runTime.deltaTValue(),
+                solver.maxDeltaT()
+            )
+        );
         Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
     }
 }

src/finiteVolume/solver/solver.C

@@ -35,6 +35,9 @@ namespace Foam
 }
 
 
+const Foam::scalar Foam::solver::maxIncreaseDeltaT = 1.2;
+
+
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
 bool Foam::solver::writeData(Ostream&) const

src/finiteVolume/solver/solver.H

@@ -76,6 +76,12 @@ public:
         bool LTS;
 
 
+    // Public Static Data
+
+        //- Maximum fractional increase in deltaT
+        static const scalar maxIncreaseDeltaT;
+
+
 private:
 
     // Private Member Data