ENH: cellToFace: new selection option 'outside'

The new selection option 'outside' can be used to select
faces with only one neighbour in the specified cellSet.

src/meshTools/topoSet/faceSources/cellToFace/cellToFace.C

@@ -48,11 +48,12 @@ namespace Foam
 Foam::topoSetSource::addToUsageTable Foam::cellToFace::usage_
 (
     cellToFace::typeName,
-    "\n    Usage: cellToFace <cellSet> all|both\n\n"
+    "\n    Usage: cellToFace <cellSet> all|both|outside\n\n"
     "    Select -all : all faces of cells in the cellSet\n"
     "           -both: faces where both neighbours are in the cellSet\n\n"
 );
 
+
 const Foam::Enum
 <
     Foam::cellToFace::cellAction
@@ -61,6 +62,7 @@ Foam::cellToFace::cellActionNames_
 ({
     { cellAction::ALL, "all" },
     { cellAction::BOTH, "both" },
+    { cellAction::OUTSIDE, "outside" }
 });
 
 
@@ -148,6 +150,65 @@ void Foam::cellToFace::combine
             }
         }
     }
+    else if (option_ == OUTSIDE)
+    {
+        // Add all faces where only one neighbour is in set.
+
+        const label nInt = mesh_.nInternalFaces();
+        const labelList& own = mesh_.faceOwner();
+        const labelList& nei = mesh_.faceNeighbour();
+        const polyBoundaryMesh& patches = mesh_.boundaryMesh();
+
+
+        // Check all internal faces
+        for (label facei = 0; facei < nInt; ++facei)
+        {
+            if (cellLabels.found(own[facei]) != cellLabels.found(nei[facei]))
+            {
+                addOrDelete(set, facei, add);
+            }
+        }
+
+
+        // Get coupled cell status
+        boolList neiInSet(mesh_.nBoundaryFaces(), false);
+
+        for (const polyPatch& pp : patches)
+        {
+            if (pp.coupled())
+            {
+                label facei = pp.start();
+                forAll(pp, i)
+                {
+                    neiInSet[facei-nInt] = cellLabels.found(own[facei]);
+                    ++facei;
+                }
+            }
+        }
+        syncTools::swapBoundaryFaceList(mesh_, neiInSet);
+
+
+        // Check all boundary faces
+        for (const polyPatch& pp : patches)
+        {
+            label facei = pp.start();
+            forAll(pp, i)
+            {
+                if (cellLabels.found(own[facei]) != neiInSet[facei-nInt])
+                {
+                    addOrDelete(set, facei, add);
+                }
+                ++facei;
+            }
+        }
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Selected option is not available"
+            << ", option: " << cellActionNames_[option_]
+            << exit(FatalError);
+    }
 }
 
 

src/meshTools/topoSet/faceSources/cellToFace/cellToFace.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
-    Copyright (C) 2018-2020 OpenCFD Ltd.
+    Copyright (C) 2018-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,8 +33,8 @@ Description
     Operands:
     \table
       Operand   | Type       | Location
-      input     | cellSet(s) | $FOAM_CASE/constant/polyMesh/sets/\<set\>
-      output    | faceSet    | $FOAM_CASE/constant/polyMesh/sets/\<set\>
+      input     | cellSet(s) | constant/polyMesh/sets/\<set\>
+      output    | faceSet    | constant/polyMesh/sets/\<set\>
     \endtable
 
 Usage
@@ -68,7 +68,7 @@ Usage
 
     where the entries mean:
     \table
-      Property   | Description                         | Type | Req'd | Dflt
+      Property   | Description                         | Type |  Reqd | Deflt
       name       | Name of faceSet                     | word |  yes  | -
       type       | Type name: faceSet                  | word |  yes  | -
       action     | Action applied on faces - see below | word |  yes  | -
@@ -87,18 +87,20 @@ Usage
     \verbatim
       all     | All faces of cells in the cellSet
       both    | Faces where both neighbours are in the cellSet
+      outside | Faces with only one neighbour in the cellSet
     \endverbatim
 
     Options for the conditional mandatory entries:
     \verbatim
-      Entry    | Description                    | Type     | Req'd  | Dflt
-      sets     | Names of input cellSets        | wordList | cond'l | -
-      set      | Name of input cellSet          | word     | cond'l | -
+      Entry    | Description                    | Type     | Reqd   | Deflt
+      sets     | Names of input cellSets        | wordList | choice | -
+      set      | Name of input cellSet          | word     | choice | -
     \endverbatim
 
 Note
-    The order of precedence among the conditional mandatory entries from the
+  - The order of precedence among the conditional mandatory entries from the
     highest to the lowest is \c sets, and \c set.
+  - The \c outside option applies to the cellSets individually.
 
 See also
     - Foam::topoSetSource
@@ -109,8 +111,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef cellToFace_H
-#define cellToFace_H
+#ifndef Foam_cellToFace_H
+#define Foam_cellToFace_H
 
 #include "topoSetFaceSource.H"
 #include "Enum.H"
@@ -121,7 +123,7 @@ namespace Foam
 {
 
 /*---------------------------------------------------------------------------*\
-                           Class cellToFace Declaration
+                        Class cellToFace Declaration
 \*---------------------------------------------------------------------------*/
 
 class cellToFace
@@ -133,7 +135,8 @@ public:
         enum cellAction
         {
             ALL,
-            BOTH
+            BOTH,
+            OUTSIDE
         };
 
 

tutorials/incompressible/pisoFoam/RAS/cavity/system/topoSetDict

@@ -303,6 +303,15 @@ actions
         set     cylinder1;
     }
 
+    {
+        name    faceCell1c;
+        type    faceSet;
+        action  new;
+        source  cellToFace;
+        option  outside;
+        set     cylinder1;
+    }
+
     {
         name        faceCylinder1;
         type        faceSet;