diff --git a/etc/templates/compressibleInflowOutflow/README b/etc/templates/compressibleInflowOutflow/README
index 780ced0069..33306e9fc1 100644
--- a/etc/templates/compressibleInflowOutflow/README
+++ b/etc/templates/compressibleInflowOutflow/README
@@ -12,19 +12,13 @@ Background Mesh
 ===============
 + The user should establish the bounds of their CAD.obj file
 + The blockMeshDict file contains a backgroundMesh subditionary
-+ Set xMin, xMax, etc to be beyond the CAD.obj bounds
++ For internal flows, where CAD.obj describes the external boundary, set xMin,
+  xMax, etc to be beyond the CAD.obj bounds
++ For external flows, the background mesh can define the external boundary by
+  uncommenting entries, e.g. inlet, in the boundary section of blockMeshDict
 + Set background mesh density with xCells, yCells, zCells
 + Run blockMesh
 
-Background Mesh (alternative)
-=============================
-+ The user can adopt the background mesh patches in the mesh
-+ For example, the background mesh can provide external patches of an external
-  flow
-+ An alternative blockMeshDict file is set up for this: blockMeshDict.extPatches
-+ Simply copy blockMeshDict.extPatches to blockMeshDict and edit inlet, outlet
-  patches accordingly
-
 Castellated Mesh
 ================
 + In the snappyHexMeshDict file, replace <inletPatch> with the name of the inlet
diff --git a/etc/templates/compressibleInflowOutflow/system/blockMeshDict b/etc/templates/compressibleInflowOutflow/system/blockMeshDict
index de6aabcfd1..f72145d4bb 100644
--- a/etc/templates/compressibleInflowOutflow/system/blockMeshDict
+++ b/etc/templates/compressibleInflowOutflow/system/blockMeshDict
@@ -59,6 +59,61 @@ edges
 
 boundary
 (
+/*
+    left
+    {
+        type patch;
+        faces
+        (
+            (0 3 7 4)
+        );
+    }
+
+    right
+    {
+        type patch;
+        faces
+        (
+            (1 5 6 2)
+        );
+    }
+
+    bottom
+    {
+        type patch;
+        faces
+        (
+            (0 1 2 3)
+        );
+    }
+
+    top
+    {
+        type patch;
+        faces
+        (
+            (4 7 6 5)
+        );
+    }
+
+    back
+    {
+        type patch;
+        faces
+        (
+            (0 4 5 1)
+        );
+    }
+
+    front
+    {
+        type patch;
+        faces
+        (
+            (3 2 6 7)
+        );
+    }
+*/
 );
 
 mergePatchPairs
diff --git a/etc/templates/compressibleInflowOutflow/system/blockMeshDict.extPatches b/etc/templates/compressibleInflowOutflow/system/blockMeshDict.extPatches
deleted file mode 100644
index 3286dba7e1..0000000000
--- a/etc/templates/compressibleInflowOutflow/system/blockMeshDict.extPatches
+++ /dev/null
@@ -1,121 +0,0 @@
-/*--------------------------------*- C++ -*----------------------------------*\
-| =========                 |                                                 |
-| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
-|  \\    /   O peration     | Version:  dev                                   |
-|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
-|    \\/     M anipulation  |                                                 |
-\*---------------------------------------------------------------------------*/
-FoamFile
-{
-    version     2.0;
-    format      ascii;
-    class       dictionary;
-    object      blockMeshDict;
-}
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-backgroundMesh
-{
-    xMin    -1;
-    xMax     1;
-    yMin    -1;
-    yMax     1;
-    zMin    -1;
-    zMax     1;
-    xCells  20;
-    yCells  20;
-    zCells  20;
-}
-
-convertToMeters 1;
-
-vertices
-(
-    ($:backgroundMesh.xMin $:backgroundMesh.yMin $:backgroundMesh.zMin)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMin $:backgroundMesh.zMin)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMax $:backgroundMesh.zMin)
-    ($:backgroundMesh.xMin $:backgroundMesh.yMax $:backgroundMesh.zMin)
-
-    ($:backgroundMesh.xMin $:backgroundMesh.yMin $:backgroundMesh.zMax)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMin $:backgroundMesh.zMax)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMax $:backgroundMesh.zMax)
-    ($:backgroundMesh.xMin $:backgroundMesh.yMax $:backgroundMesh.zMax)
-);
-
-blocks
-(
-    hex (0 1 2 3 4 5 6 7)
-    (
-        $:backgroundMesh.xCells
-        $:backgroundMesh.yCells
-        $:backgroundMesh.zCells
-    )
-    simpleGrading (1 1 1)
-);
-
-edges
-(
-);
-
-boundary
-(
-    left
-    {
-        type patch;
-        faces
-        (
-            (0 3 7 4)
-        );
-    }
-
-    right
-    {
-        type patch;
-        faces
-        (
-            (1 5 6 2)
-        );
-    }
-
-    bottom
-    {
-        type patch;
-        faces
-        (
-            (0 1 2 3)
-        );
-    }
-
-    top
-    {
-        type patch;
-        faces
-        (
-            (4 7 6 5)
-        );
-    }
-
-    back
-    {
-        type patch;
-        faces
-        (
-            (0 4 5 1)
-        );
-    }
-
-    front
-    {
-        type patch;
-        faces
-        (
-            (3 2 6 7)
-        );
-    }
-);
-
-mergePatchPairs
-(
-);
-
-// ************************************************************************* //
diff --git a/etc/templates/inflowOutflow/README b/etc/templates/inflowOutflow/README
index 3cac200bdc..a3d48a0c94 100644
--- a/etc/templates/inflowOutflow/README
+++ b/etc/templates/inflowOutflow/README
@@ -12,19 +12,13 @@ Background Mesh
 ===============
 + The user should establish the bounds of their CAD.obj file
 + The blockMeshDict file contains a backgroundMesh subditionary
-+ Set xMin, xMax, etc to be beyond the CAD.obj bounds
++ For internal flows, where CAD.obj describes the external boundary, set xMin,
+  xMax, etc to be beyond the CAD.obj bounds
++ For external flows, the background mesh can define the external boundary by
+  uncommenting entries, e.g. inlet, in the boundary section of blockMeshDict
 + Set background mesh density with xCells, yCells, zCells
 + Run blockMesh
 
-Background Mesh (alternative)
-=============================
-+ The user can adopt the background mesh patches in the mesh
-+ For example, the background mesh can provide external patches of an external
-  flow
-+ An alternative blockMeshDict file is set up for this: blockMeshDict.extPatches
-+ Simply copy blockMeshDict.extPatches to blockMeshDict and edit inlet, outlet
-  patches accordingly
-
 Castellated Mesh
 ================
 + In the snappyHexMeshDict file, replace <inletPatch> with the name of the inlet
diff --git a/etc/templates/inflowOutflow/system/blockMeshDict b/etc/templates/inflowOutflow/system/blockMeshDict
index de6aabcfd1..f72145d4bb 100644
--- a/etc/templates/inflowOutflow/system/blockMeshDict
+++ b/etc/templates/inflowOutflow/system/blockMeshDict
@@ -59,6 +59,61 @@ edges
 
 boundary
 (
+/*
+    left
+    {
+        type patch;
+        faces
+        (
+            (0 3 7 4)
+        );
+    }
+
+    right
+    {
+        type patch;
+        faces
+        (
+            (1 5 6 2)
+        );
+    }
+
+    bottom
+    {
+        type patch;
+        faces
+        (
+            (0 1 2 3)
+        );
+    }
+
+    top
+    {
+        type patch;
+        faces
+        (
+            (4 7 6 5)
+        );
+    }
+
+    back
+    {
+        type patch;
+        faces
+        (
+            (0 4 5 1)
+        );
+    }
+
+    front
+    {
+        type patch;
+        faces
+        (
+            (3 2 6 7)
+        );
+    }
+*/
 );
 
 mergePatchPairs
diff --git a/etc/templates/inflowOutflow/system/blockMeshDict.extPatches b/etc/templates/inflowOutflow/system/blockMeshDict.extPatches
deleted file mode 100644
index 3286dba7e1..0000000000
--- a/etc/templates/inflowOutflow/system/blockMeshDict.extPatches
+++ /dev/null
@@ -1,121 +0,0 @@
-/*--------------------------------*- C++ -*----------------------------------*\
-| =========                 |                                                 |
-| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
-|  \\    /   O peration     | Version:  dev                                   |
-|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
-|    \\/     M anipulation  |                                                 |
-\*---------------------------------------------------------------------------*/
-FoamFile
-{
-    version     2.0;
-    format      ascii;
-    class       dictionary;
-    object      blockMeshDict;
-}
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-backgroundMesh
-{
-    xMin    -1;
-    xMax     1;
-    yMin    -1;
-    yMax     1;
-    zMin    -1;
-    zMax     1;
-    xCells  20;
-    yCells  20;
-    zCells  20;
-}
-
-convertToMeters 1;
-
-vertices
-(
-    ($:backgroundMesh.xMin $:backgroundMesh.yMin $:backgroundMesh.zMin)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMin $:backgroundMesh.zMin)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMax $:backgroundMesh.zMin)
-    ($:backgroundMesh.xMin $:backgroundMesh.yMax $:backgroundMesh.zMin)
-
-    ($:backgroundMesh.xMin $:backgroundMesh.yMin $:backgroundMesh.zMax)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMin $:backgroundMesh.zMax)
-    ($:backgroundMesh.xMax $:backgroundMesh.yMax $:backgroundMesh.zMax)
-    ($:backgroundMesh.xMin $:backgroundMesh.yMax $:backgroundMesh.zMax)
-);
-
-blocks
-(
-    hex (0 1 2 3 4 5 6 7)
-    (
-        $:backgroundMesh.xCells
-        $:backgroundMesh.yCells
-        $:backgroundMesh.zCells
-    )
-    simpleGrading (1 1 1)
-);
-
-edges
-(
-);
-
-boundary
-(
-    left
-    {
-        type patch;
-        faces
-        (
-            (0 3 7 4)
-        );
-    }
-
-    right
-    {
-        type patch;
-        faces
-        (
-            (1 5 6 2)
-        );
-    }
-
-    bottom
-    {
-        type patch;
-        faces
-        (
-            (0 1 2 3)
-        );
-    }
-
-    top
-    {
-        type patch;
-        faces
-        (
-            (4 7 6 5)
-        );
-    }
-
-    back
-    {
-        type patch;
-        faces
-        (
-            (0 4 5 1)
-        );
-    }
-
-    front
-    {
-        type patch;
-        faces
-        (
-            (3 2 6 7)
-        );
-    }
-);
-
-mergePatchPairs
-(
-);
-
-// ************************************************************************* //