ENH: leak-detection. Fixes #1572.

The final leak can only be decided once all cells have been
deleted. So only exit on final invocation and give warning-only
beforehand. This avoids a lot of false positives.
The tutorial itself didn't actually produce a mesh with leakage
with the old settings. Upped the refinement level to force it
to go through the hole in the geometry.

src/mesh/snappyHexMesh/meshRefinement/meshRefinement.C

@@ -2514,6 +2514,7 @@ Foam::label Foam::meshRefinement::findRegions
     const vector& perturbVec,
     const pointField& locationsInMesh,
     const pointField& locationsOutsideMesh,
+    const bool exitIfLeakPath,
     const writer<scalar>& leakPathFormatter,
     const label nRegions,
     labelList& cellRegion,
@@ -2725,6 +2726,8 @@ Foam::label Foam::meshRefinement::findRegions
 
                 Pstream::scatter(fName);
 
+                if (exitIfLeakPath)
+                {
                     FatalErrorInFunction
                         << "Location in mesh " << locationsInMesh[index]
                         << " is inside same mesh region " << regioni
@@ -2733,6 +2736,16 @@ Foam::label Foam::meshRefinement::findRegions
                         << nl << "    Dumped leak path to " << fName
                         << exit(FatalError);
                 }
+                else
+                {
+                    WarningInFunction
+                        << "Location in mesh " << locationsInMesh[index]
+                        << " is inside same mesh region " << regioni
+                        << " as one of the locations outside mesh "
+                        << locationsOutsideMesh
+                        << nl << "Dumped leak path to " << fName << endl;
+                }
+            }
         }
     }
 
@@ -2763,6 +2776,7 @@ Foam::autoPtr<Foam::mapPolyMesh> Foam::meshRefinement::splitMeshRegions
     const labelList& globalToSlavePatch,
     const pointField& locationsInMesh,
     const pointField& locationsOutsideMesh,
+    const bool exitIfLeakPath,
     const writer<scalar>& leakPathFormatter
 )
 {
@@ -2783,6 +2797,7 @@ Foam::autoPtr<Foam::mapPolyMesh> Foam::meshRefinement::splitMeshRegions
         mergeDistance_ * vector::one,   // perturbVec
         locationsInMesh,
         locationsOutsideMesh,
+        exitIfLeakPath,
         leakPathFormatter,
         cellRegion.nRegions(),
         cellRegion,

src/mesh/snappyHexMesh/meshRefinement/meshRefinement.H

@@ -1439,6 +1439,7 @@ public:
                 const vector& perturbVec,
                 const pointField& locationsInMesh,
                 const pointField& locationsOutsideMesh,
+                const bool exitIfLeakPath,
                 const writer<scalar>& leakPathFormatter,
                 const label nRegions,
                 labelList& cellRegion,
@@ -1453,6 +1454,7 @@ public:
                 const labelList& globalToSlavePatch,
                 const pointField& locationsInMesh,
                 const pointField& locationsOutsideMesh,
+                const bool exitIfLeakPath,
                 const writer<scalar>& leakPathFormatter
             );
 

src/mesh/snappyHexMesh/meshRefinement/meshRefinementBaffles.C

@@ -4258,6 +4258,7 @@ void Foam::meshRefinement::baffleAndSplitMesh
         globalToSlavePatch,
         locationsInMesh,
         locationsOutsideMesh,
+        true,       // Exit if any connection between inside and outside
         leakPathFormatter
     );
 
@@ -4368,6 +4369,7 @@ void Foam::meshRefinement::mergeFreeStandingBaffles
             globalToSlavePatch,
             locationsInMesh,
             locationsOutsideMesh,
+            true,   // Exit if any connection between inside and outside
             leakPathFormatter
         );
 
@@ -4443,6 +4445,7 @@ Foam::autoPtr<Foam::mapPolyMesh> Foam::meshRefinement::splitMesh
         mergeDistance_ * vector::one,   // perturbVec
         locationsInMesh,
         locationsOutsideMesh,
+        false,      // do not exit if outside location found
         leakPathFormatter,
         cellRegion.nRegions(),
         cellRegion,

src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyRefineDriver.C

@@ -2700,6 +2700,7 @@ void Foam::snappyRefineDriver::splitAndMergeBaffles
             globalToSlavePatch_,
             refineParams.locationsInMesh(),
             refineParams.locationsOutsideMesh(),
+            true,   // exit if any path to outside points
             setFormatter_
         );
 

tutorials/mesh/snappyHexMesh/motorBike_leakDetection/system/snappyHexMeshDict

@@ -119,7 +119,7 @@ castellatedMeshControls
         "motorBike.*"
         {
             // Surface-wise min and max refinement level
-            level (5 6);
+            level (6 6);
 
             // Optional specification of patch type (default is wall). No
             // constraint types (cyclic, symmetry) etc. are allowed.