potentialFoam: Solve for velocity potential named Phi rather than using the pressure field for this purpose

The Phi field is read if available otherwise created automatically with
boundary conditions obtained automatically from the pressure field if
available (with optional name) otherwise inferred from the velocity
field.  Phi Laplacian scheme and solver specification are required.  See
tutorials for examples.

tutorials/incompressible/pisoFoam/les/motorBike/motorBike/system/fvSchemes

@@ -55,7 +55,8 @@ snGradSchemes
 fluxRequired
 {
     default         no;
-    p               ;
+    p;
+    Phi;
 }
 
 wallDist

tutorials/incompressible/pisoFoam/les/motorBike/motorBike/system/fvSolution

@@ -38,6 +38,11 @@ solvers
         relTol          0;
     };
 
+    Phi
+    {
+        $p;
+    }
+
     "(U|nuTilda)"
     {
         solver          smoothSolver;

tutorials/incompressible/simpleFoam/motorBike/system/fvSchemes

@@ -53,6 +53,7 @@ fluxRequired
 {
     default         no;
     p;
+    Phi;
 }
 
 wallDist

tutorials/incompressible/simpleFoam/motorBike/system/fvSolution

@@ -30,6 +30,11 @@ solvers
         mergeLevels      1;
     }
 
+    Phi
+    {
+        $p;
+    }
+
     U
     {
         solver           smoothSolver;

tutorials/incompressible/simpleFoam/pipeCyclic/Allrun

@@ -7,26 +7,6 @@ cd ${0%/*} || exit 1    # Run from this directory
 # Get application directory
 application=`getApplication`
 
-# This case uses the #codeStream which is disabled by default. Enable for
-# just this case.
-MAIN_CONTROL_DICT=`foamEtcFile controlDict`
-if [ -f "$MAIN_CONTROL_DICT" ]
-then
-    echo "Modifying ${MAIN_CONTROL_DICT} to enable allowSystemOperations"
-
-    # Clean up on termination and on Ctrl-C
-    trap 'mv ${MAIN_CONTROL_DICT}.$$ ${MAIN_CONTROL_DICT} 2>/dev/null; exit 0' \
-        EXIT TERM INT
-    cp ${MAIN_CONTROL_DICT} ${MAIN_CONTROL_DICT}.$$
-
-    echo "Enabling allowSystemOperations in ${MAIN_CONTROL_DICT}."
-
-    sed \
-    -e s/"\(allowSystemOperations[ \t]*\)\([0-9]\);"/"\1 1;"/g \
-    ${MAIN_CONTROL_DICT}.$$ > ${MAIN_CONTROL_DICT}
-fi
-
-
 runApplication blockMesh
 runApplication topoSet
 runApplication refineHexMesh c0 -overwrite