ENH: autoHexMesh: allow location-in-mesh to be made into a cellZone

Normally the location-in-mesh is equivalent to a cellZone -1. This can
now be overridden by a surface-specified cellZone as before.

applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C

@@ -58,6 +58,7 @@ Description
 #include "globalIndex.H"
 #include "IOmanip.H"
 #include "decompositionModel.H"
+#include "fvMeshTools.H"
 
 using namespace Foam;
 
@@ -813,6 +814,7 @@ int main(int argc, char *argv[])
         readScalar(meshDict.lookup("mergeTolerance"))
     );
 
+    const Switch keepPatches(meshDict.lookupOrDefault("keepPatches", false));
 
 
     // Read decomposePar dictionary
@@ -1517,6 +1519,12 @@ int main(int argc, char *argv[])
             motionDict
         );
 
+        // Remove zero sized patches originating from faceZones
+        if (!keepPatches && !wantSnap && !wantLayers)
+        {
+            fvMeshTools::removeEmptyPatches(mesh, true);
+        }
+
         writeMesh
         (
             "Refined mesh",
@@ -1559,6 +1567,12 @@ int main(int argc, char *argv[])
             snapParams
         );
 
+        // Remove zero sized patches originating from faceZones
+        if (!keepPatches && !wantLayers)
+        {
+            fvMeshTools::removeEmptyPatches(mesh, true);
+        }
+
         writeMesh
         (
             "Snapped mesh",
@@ -1609,6 +1623,12 @@ int main(int argc, char *argv[])
             distributor
         );
 
+        // Remove zero sized patches originating from faceZones
+        if (!keepPatches)
+        {
+            fvMeshTools::removeEmptyPatches(mesh, true);
+        }
+
         writeMesh
         (
             "Layer mesh",
@@ -1622,6 +1642,7 @@ int main(int argc, char *argv[])
     }
 
 
+
     {
         // Check final mesh
         Info<< "Checking final mesh ..." << endl;

src/dynamicMesh/fvMeshTools/fvMeshTools.C

@@ -355,6 +355,69 @@ void Foam::fvMeshTools::reorderPatches
 }
 
 
+Foam::labelList Foam::fvMeshTools::removeEmptyPatches
+(
+    fvMesh& mesh,
+    const bool validBoundary
+)
+{
+    const polyBoundaryMesh& pbm = mesh.boundaryMesh();
+
+    labelList newToOld(pbm.size());
+    labelList oldToNew(pbm.size(), -1);
+    label newI = 0;
+
+
+    // Assumes all non-coupled boundaries are on all processors!
+    forAll(pbm, patchI)
+    {
+        const polyPatch& pp = pbm[patchI];
+
+        if (!isA<processorPolyPatch>(pp))
+        {
+            label nFaces = pp.size();
+            if (validBoundary)
+            {
+                reduce(nFaces, sumOp<label>());
+            }
+
+            if (nFaces > 0)
+            {
+                newToOld[newI] = patchI;
+                oldToNew[patchI] = newI++;
+            }
+        }
+    }
+
+    // Same for processor patches (but need no reduction)
+    forAll(pbm, patchI)
+    {
+        const polyPatch& pp = pbm[patchI];
+
+        if (isA<processorPolyPatch>(pp) && pp.size())
+        {
+            newToOld[newI] = patchI;
+            oldToNew[patchI] = newI++;
+        }
+    }
+
+    newToOld.setSize(newI);
+
+    // Move all deleteable patches to the end
+    forAll(oldToNew, patchI)
+    {
+        if (oldToNew[patchI] == -1)
+        {
+            oldToNew[patchI] = newI++;
+        }
+    }
+
+    reorderPatches(mesh, oldToNew, newToOld.size(), validBoundary);
+
+    return newToOld;
+}
+
+
 Foam::autoPtr<Foam::fvMesh> Foam::fvMeshTools::newMesh
 (
     const IOobject& io,

src/dynamicMesh/fvMeshTools/fvMeshTools.H

@@ -113,7 +113,7 @@ public:
     static void zeroPatchFields(fvMesh& mesh, const label patchI);
 
     //- Reorder and remove trailing patches. If validBoundary call is parallel
-    //  synced and all add the same patch with same settings
+    //  synced
     static void reorderPatches
     (
         fvMesh&,
@@ -122,6 +122,11 @@ public:
         const bool validBoundary
     );
 
+    //- Remove zero sized patches. All but processor patches are
+    //  assumed to be present on all processors (so size will be reduced
+    //  if validBoundary). Return map from new
+    //  to old patches
+    static labelList removeEmptyPatches(fvMesh&, const bool validBoundary);
 
     //- Read mesh or create dummy mesh (0 cells, >0 patches). Works in two
     //  modes according to masterOnlyReading:
@@ -133,7 +138,6 @@ public:
         const IOobject& io,
         const bool masterOnlyReading
     );
-
 };
 
 

src/mesh/autoMesh/autoHexMesh/meshRefinement/meshRefinementBaffles.C

@@ -1390,14 +1390,21 @@ void Foam::meshRefinement::findCellZoneGeometric
 
     forAll(insideSurfaces, cellI)
     {
-        if (cellToZone[cellI] == -2)
-        {
-            label surfI = insideSurfaces[cellI];
+        label surfI = insideSurfaces[cellI];
 
-            if (surfI != -1)
+        if (surfI != -1)
+        {
+            if (cellToZone[cellI] == -2)
             {
                 cellToZone[cellI] = surfaceToCellZone[surfI];
             }
+            else if (cellToZone[cellI] == -1)
+            {
+                // ? Allow named surface to override background zone (-1)
+                // This is used in the multiRegionHeater tutorial where the
+                // locationInMesh is inside a named surface.
+                cellToZone[cellI] = surfaceToCellZone[surfI];
+            }
         }
     }