improvements

PotentialFlow/magnus.pro

 /* -------------------------------------------------------------------
-   Tutorial 6 : Potential flow, lift and Magnus effect
+   Tutorial 6 : Potential flow and Magnus effect
 
    Features:
-   - Potential flow, irrotational flow, lift and Magnus effect
+   - Potential flow, irrotational flow
    - Multivalued scalar field
-   - Non-linear iteration on an Associated global quantity
-   - Use a run-time variable in a Post-Operation 
+   - Lift and Magnus effect, stagnation points
+   - Run-time variables
+   - Elementary algorithms in the Resolution section
+   - Non-linear iteration to achieve Kutta's condition
 
    To compute the solution in a terminal: 
      getdp magnus.pro -solve PotentialFlow -pos PotentialFlow
@@ -89,8 +91,6 @@
    f(V) = argVTrail[ {d phi } ] OnPoint {1.0001,0,0}
 
    comes below a fixed tolerance.
-
-   
  */
 
 Include "magnus_common.pro";
@@ -244,12 +244,22 @@ Resolution{
         Generate[A]; Solve[A]; SaveSolution[A];
 
       Else
-	// Pseudo-Newton iteration to determine Dmdt in the Airfoil case.
+	// A resolution can contain elementary algorithms.
+	// Available commands are:
+	// Evaluate[] : affectation of a run-time variable
+	// Test[]{}{} : logical test
+	// While[]{} : iteration
+        // Print[{}, Format ..., File ...] : formatted display
+
+	// A pseudo-Newton iteration is implemented here 
+	// to determine the value of Dmdt (in the Airfoil case)
+	// that verifies Kutta's condition. 
 	// The run-time variable $newDmdt is used in Generate[A]
         // whereas $circ, $dmdt, $argV and $phiTrailing are evaluated 
 	// by the PostOperation[Trailing].
-	// A file containing "PhiTrailing = $phiTrailing;" is after all
-	// written on disk to be used for formatting the 
+	// A file containing "PhiTrailing = $phiTrailing;" is 
+	// after convergence written on disk to be used 
+	// for formatting purposes in the PostOperation section.  
 
 	DeleteFile["KJiter.txt"];
 
@@ -265,11 +275,9 @@ Resolution{
 	    Format "iter = %3g Circ = %5.2f Dmdt = %5.2f argV = %5.2e"];
 
         While[ Norm[ $argV ] > 1e-3 && $syscount < 50] {
-
 	  Test[ $syscount && Norm[$argV-$argVp] > 1e-3 ]
 	    {Evaluate[$jac = Min[ ($dmdt-$dmdtp)/($argV-$argVp), 0.2 ] ] ;}
   	    {Evaluate[$jac = 0.2];}
-	  Print[{$jac}, Format "Jac = %7.5e"];
 
 	  Evaluate[$newDmdt = $dmdt - $jac * $argV];
 	  Evaluate[ $syscount = $syscount + 1 ];
@@ -371,10 +379,10 @@ PostOperation{
       Print[normVelocity, OnElementsOf Vol_rho, File "p.pos"];
       Echo[ Str["l=PostProcessing.NbViews-1;",
 		"View[l].Name = 'stagnation points';",
-		"View[l].ScaleType = 2;"],
+		"View[l].ScaleType = 2; // log scale"],
 	    File "tmp.geo", LastTimeStepOnly] ;
 
-      // Show the isovalue phi=$PhiTrailing
+      // Show the isovalue "phi=$PhiTrailing"
       // which should be perpendicular to the airfoil
       // if the Kutta condition is fulfilled
       Print[phi, OnElementsOf Vol_rho, File "KJ.pos"];
@@ -382,8 +390,8 @@ PostOperation{
 	       "l=PostProcessing.NbViews-1;",
 	       "View[l].Name = 'isovalue phiTrailing';",
 	       "View[l].IntervalsType = 3;",
-	       "Mesh.SurfaceEdges = 0;",
-	       "View[l].RangeType = 2;",
+	       "Mesh.SurfaceEdges = 0; // hide mesh",
+	       "View[l].RangeType = 2; // custom range",
 	       "View[l].CustomMin = PhiTrailing;",
 	       "View[l].CustomMax = 1.001*PhiTrailing;",
 	       "View[l].NbIso = 10;"],