tutorials/incompressible/simpleFoam/pitzDaily: Change default model to kEpsilon

and reduce relaxation factors to improve stability over a range of
models and systems.

tutorials/incompressible/simpleFoam/pitzDaily/constant/turbulenceProperties

@@ -21,7 +21,7 @@ RAS
 {
     // Tested with kEpsilon, realizableKE, kOmega, kOmegaSST, v2f,
     // ShihQuadraticKE, LienCubicKE.
-    RASModel        v2f;
+    RASModel        kEpsilon;
 
     turbulence      on;
 

tutorials/incompressible/simpleFoam/pitzDaily/system/fvSolution

@@ -57,8 +57,8 @@ relaxationFactors
 {
     equations
     {
-        U               0.95;
-        ".*"            0.95;
+        U               0.9; // 0.9 is more stable but 0.95 more convergent
+        ".*"            0.9; // 0.9 is more stable but 0.95 more convergent
     }
 }