diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/T b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/T
new file mode 100644
index 0000000000000000000000000000000000000000..3bf09662bb0a143ba6281b3e9f135607ea59eefe
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/T
@@ -0,0 +1,56 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object T;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [0 0 0 1 0 0 0];
+
+internalField uniform 293;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type zeroGradient;
+ }
+
+ topAndBottom
+ {
+ type zeroGradient;
+ }
+
+ hot
+ {
+ type externalCoupledTemperature;
+ commsDir "${FOAM_CASE}/comms";
+ fileName "data";
+ initByExternal yes;
+ log true;
+ value uniform 307.75; // 34.6 degC
+ }
+
+ cold
+ {
+ type externalCoupledTemperature;
+ commsDir "${FOAM_CASE}/comms";
+ fileName "data";
+ initByExternal yes;
+ log true;
+ value uniform 288.15; // 15 degC
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/U b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/U
new file mode 100644
index 0000000000000000000000000000000000000000..2d917d036faaa2d227ec7ef69f7338d00b670f22
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/U
@@ -0,0 +1,50 @@
+/*--------------------------------*- 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 volVectorField;
+ location "0";
+ object U;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [0 1 -1 0 0 0 0];
+
+internalField uniform (0 0 0);
+
+boundaryField
+{
+ frontAndBack
+ {
+ type fixedValue;
+ value uniform (0 0 0);
+ }
+
+ topAndBottom
+ {
+ type fixedValue;
+ value uniform (0 0 0);
+ }
+
+ hot
+ {
+ type fixedValue;
+ value uniform (0 0 0);
+ }
+
+ cold
+ {
+ type fixedValue;
+ value uniform (0 0 0);
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/alphat b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/alphat
new file mode 100644
index 0000000000000000000000000000000000000000..9e486ba21571232468addb9c24008bcaebb3be18
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/alphat
@@ -0,0 +1,51 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object alphat;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [1 -1 -1 0 0 0 0];
+
+internalField uniform 0;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type compressible::alphatWallFunction;
+ Prt 0.85;
+ value uniform 0;
+ }
+ topAndBottom
+ {
+ type compressible::alphatWallFunction;
+ Prt 0.85;
+ value uniform 0;
+ }
+ hot
+ {
+ type compressible::alphatWallFunction;
+ Prt 0.85;
+ value uniform 0;
+ }
+ cold
+ {
+ type compressible::alphatWallFunction;
+ Prt 0.85;
+ value uniform 0;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/epsilon b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/epsilon
new file mode 100644
index 0000000000000000000000000000000000000000..da6d89154851331611a27d6b49a58efd89858852
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/epsilon
@@ -0,0 +1,47 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object epsilon;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [0 2 -3 0 0 0 0];
+
+internalField uniform 4e-06;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type compressible::epsilonWallFunction;
+ value uniform 4e-06;
+ }
+ topAndBottom
+ {
+ type compressible::epsilonWallFunction;
+ value uniform 4e-06;
+ }
+ hot
+ {
+ type compressible::epsilonWallFunction;
+ value uniform 4e-06;
+ }
+ cold
+ {
+ type compressible::epsilonWallFunction;
+ value uniform 4e-06;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/k b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/k
new file mode 100644
index 0000000000000000000000000000000000000000..886667fb5c3f9345b3bcd01d6af87fd49d640837
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/k
@@ -0,0 +1,47 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object k;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [0 2 -2 0 0 0 0];
+
+internalField uniform 3.75e-04;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type compressible::kqRWallFunction;
+ value uniform 3.75e-04;
+ }
+ topAndBottom
+ {
+ type compressible::kqRWallFunction;
+ value uniform 3.75e-04;
+ }
+ hot
+ {
+ type compressible::kqRWallFunction;
+ value uniform 3.75e-04;
+ }
+ cold
+ {
+ type compressible::kqRWallFunction;
+ value uniform 3.75e-04;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/mut b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/mut
new file mode 100644
index 0000000000000000000000000000000000000000..0ecb8672d2758749a6119dd49183237cb1bfa503
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/mut
@@ -0,0 +1,47 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object mut;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [1 -1 -1 0 0 0 0];
+
+internalField uniform 0;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type mutUWallFunction;
+ value uniform 0;
+ }
+ topAndBottom
+ {
+ type mutUWallFunction;
+ value uniform 0;
+ }
+ hot
+ {
+ type mutUWallFunction;
+ value uniform 0;
+ }
+ cold
+ {
+ type mutUWallFunction;
+ value uniform 0;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/omega b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/omega
new file mode 100644
index 0000000000000000000000000000000000000000..423815a2de8a485bfb7829b7669a7b147a225d3e
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/omega
@@ -0,0 +1,47 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object omega;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [0 0 -1 0 0 0 0];
+
+internalField uniform 0.12;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type compressible::omegaWallFunction;
+ value uniform 0.12;
+ }
+ topAndBottom
+ {
+ type compressible::omegaWallFunction;
+ value uniform 0.12;
+ }
+ hot
+ {
+ type compressible::omegaWallFunction;
+ value uniform 0.12;
+ }
+ cold
+ {
+ type compressible::omegaWallFunction;
+ value uniform 0.12;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/p b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/p
new file mode 100644
index 0000000000000000000000000000000000000000..9b1e74247bf9946eae6d063aa536d141bee454ad
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/p
@@ -0,0 +1,50 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object p;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [1 -1 -2 0 0 0 0];
+
+internalField uniform 1e5;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type calculated;
+ value $internalField;
+ }
+
+ topAndBottom
+ {
+ type calculated;
+ value $internalField;
+ }
+
+ hot
+ {
+ type calculated;
+ value $internalField;
+ }
+
+ cold
+ {
+ type calculated;
+ value $internalField;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/p_rgh b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/p_rgh
new file mode 100644
index 0000000000000000000000000000000000000000..15979d020e33ed2769512df863c4ccb772b6eeca
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/0/p_rgh
@@ -0,0 +1,50 @@
+/*--------------------------------*- 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 volScalarField;
+ location "0";
+ object p_rgh;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [1 -1 -2 0 0 0 0];
+
+internalField uniform 1e5;
+
+boundaryField
+{
+ frontAndBack
+ {
+ type fixedFluxPressure;
+ value uniform 1e5;
+ }
+
+ topAndBottom
+ {
+ type fixedFluxPressure;
+ value uniform 1e5;
+ }
+
+ hot
+ {
+ type fixedFluxPressure;
+ value uniform 1e5;
+ }
+
+ cold
+ {
+ type fixedFluxPressure;
+ value uniform 1e5;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allclean b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allclean
new file mode 100755
index 0000000000000000000000000000000000000000..0dbf345049b678d451db10398a7c52c2f928b88c
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allclean
@@ -0,0 +1,14 @@
+#!/bin/sh
+cd ${0%/*} || exit 1 # run from this directory
+
+# Source tutorial run functions
+. $WM_PROJECT_DIR/bin/tools/CleanFunctions
+
+cleanCase
+
+rm -rf comms
+
+killall externalSolver > /dev/null 2>&1
+
+
+# ----------------------------------------------------------------- end-of-file
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun
new file mode 100755
index 0000000000000000000000000000000000000000..484bfa6c525aeb575c18ed505d7dd32af8ee99c6
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun
@@ -0,0 +1,14 @@
+#!/bin/sh
+cd ${0%/*} || exit 1 # run from this directory
+
+# Source tutorial run functions
+. $WM_PROJECT_DIR/bin/tools/RunFunctions
+
+./Allrun.pre
+
+runApplication $(getApplication) &
+
+./externalSolver
+
+
+# ----------------------------------------------------------------- end-of-file
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun-parallel b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun-parallel
new file mode 100755
index 0000000000000000000000000000000000000000..5bba5c94401d28061723de9e6f7cfc1f5460a2a4
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun-parallel
@@ -0,0 +1,16 @@
+#!/bin/sh
+cd ${0%/*} || exit 1 # run from this directory
+
+# Source tutorial run functions
+. $WM_PROJECT_DIR/bin/tools/RunFunctions
+
+./Allrun.pre
+
+runApplication decomposePar
+
+runParallel $(getApplication) 4 &
+
+./externalSolver
+
+
+# ----------------------------------------------------------------- end-of-file
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun.pre b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun.pre
new file mode 100755
index 0000000000000000000000000000000000000000..1964116a40f8c9400516a5dd5b4a2ac013c0bf88
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/Allrun.pre
@@ -0,0 +1,11 @@
+#!/bin/sh
+cd ${0%/*} || exit 1 # run from this directory
+
+# Source tutorial run functions
+. $WM_PROJECT_DIR/bin/tools/RunFunctions
+
+runApplication blockMesh
+runApplication createExternalCoupledPatchGeometry T
+
+
+# ----------------------------------------------------------------- end-of-file
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/README b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/README
new file mode 100644
index 0000000000000000000000000000000000000000..10d7392eb4814034795d02d08115ce261ce9875a
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/README
@@ -0,0 +1,5 @@
+Example of an explicit coupling between OpenFOAM and an external application
+using the externalCoupled boundary conditions.
+
+The case is based on the buoyantCavity tutorial case, whereby on each iteration
+the 'hot' and 'cold' patch temperatures are incremented by 1K.
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/RASProperties b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/RASProperties
new file mode 100644
index 0000000000000000000000000000000000000000..be86bc1efaab5bb87f00ce3f86915c671b6ef43b
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/RASProperties
@@ -0,0 +1,23 @@
+/*--------------------------------*- 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 RASProperties;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+RASModel kOmegaSST;
+
+turbulence on;
+
+printCoeffs on;
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/g b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/g
new file mode 100644
index 0000000000000000000000000000000000000000..e0ac2653b5b370ad62f6770588121d30cac51627
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/g
@@ -0,0 +1,22 @@
+/*--------------------------------*- 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 uniformDimensionedVectorField;
+ location "constant";
+ object g;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions [0 1 -2 0 0 0 0];
+value ( 0 -9.81 0 );
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/polyMesh/blockMeshDict b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/polyMesh/blockMeshDict
new file mode 100644
index 0000000000000000000000000000000000000000..5f2f1e8fd2b5032b4ee3d38fcb0a2d432d1e3077
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/polyMesh/blockMeshDict
@@ -0,0 +1,83 @@
+/*--------------------------------*- 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;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+convertToMeters 0.001;
+
+vertices
+(
+ ( 0 0 -260)
+ (76 0 -260)
+ (76 2180 -260)
+ ( 0 2180 -260)
+ ( 0 0 260)
+ (76 0 260)
+ (76 2180 260)
+ ( 0 2180 260)
+);
+
+edges
+(
+);
+
+blocks
+(
+ hex (0 1 2 3 4 5 6 7) (35 150 15) simpleGrading (1 1 1)
+);
+
+boundary
+(
+ frontAndBack
+ {
+ type wall;
+ faces
+ (
+ (0 1 5 4)
+ (2 3 7 6)
+ );
+ }
+
+ topAndBottom
+ {
+ type wall;
+ faces
+ (
+ (4 5 6 7)
+ (3 2 1 0)
+ );
+ }
+
+ hot
+ {
+ type wall;
+ faces
+ (
+ (6 5 1 2)
+ );
+ }
+
+ cold
+ {
+ type wall;
+ faces
+ (
+ (4 7 3 0)
+ );
+ }
+);
+
+mergePatchPairs
+(
+);
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/polyMesh/boundary b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/polyMesh/boundary
new file mode 100644
index 0000000000000000000000000000000000000000..7cba6d73ec3f51a6b3060c296fcc3634d9e16846
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/polyMesh/boundary
@@ -0,0 +1,46 @@
+/*--------------------------------*- 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 polyBoundaryMesh;
+ location "constant/polyMesh";
+ object boundary;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+4
+(
+ frontAndBack
+ {
+ type wall;
+ nFaces 1050;
+ startFace 228225;
+ }
+ topAndBottom
+ {
+ type wall;
+ nFaces 10500;
+ startFace 229275;
+ }
+ hot
+ {
+ type wall;
+ nFaces 2250;
+ startFace 239775;
+ }
+ cold
+ {
+ type wall;
+ nFaces 2250;
+ startFace 242025;
+ }
+)
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/thermophysicalProperties b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/thermophysicalProperties
new file mode 100644
index 0000000000000000000000000000000000000000..95579e34cb51bd580ceb7debb125ff47a8c7a6aa
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/constant/thermophysicalProperties
@@ -0,0 +1,49 @@
+/*--------------------------------*- 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;
+ location "constant";
+ object thermophysicalProperties;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+thermoType
+{
+ type heRhoThermo;
+ mixture pureMixture;
+ transport const;
+ thermo hConst;
+ equationOfState perfectGas;
+ specie specie;
+ energy sensibleEnthalpy;
+}
+
+mixture
+{
+ specie
+ {
+ nMoles 1;
+ molWeight 28.96;
+ }
+ thermodynamics
+ {
+ Cp 1004.4;
+ Hf 0;
+ }
+ transport
+ {
+ mu 1.831e-05;
+ Pr 0.705;
+ }
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/externalSolver b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/externalSolver
new file mode 100755
index 0000000000000000000000000000000000000000..ac4b78d3d1553c34ca1a4e8c1a6d282a4b740199
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/externalSolver
@@ -0,0 +1,85 @@
+#!/bin/sh
+#
+# Dummy external solver to communicate with OpenFOAM via externalCoupled
+# boundary conditions
+#
+# Functionality is hard-coded for this particular test case
+# - patch temperatures increased by 1K on each step
+#
+cd ${0%/*} || exit 1 # run from this directory
+
+echo "*** Executing dummy external solver"
+
+commsDir="comms"
+lockFile="${commsDir}/OpenFOAM.lock"
+dataFile="${commsDir}/data"
+waitSec=1
+timeOut=10
+refGrad=0
+valueFraction=1
+
+function log()
+{
+ echo "External: $@"
+}
+
+function init()
+{
+ log "initialisation: creating ${dataFile}.in"
+
+ # Hard-coded for 2 patches of size 2250
+ n=2250
+ refCold=283
+ refHot=303
+ touch "${dataFile}.in"
+ for i in $(seq 1 $n); do
+ echo "$refHot $refGrad $valueFraction" >> "${dataFile}.in"
+ done
+ for i in $(seq 1 $n); do
+ echo "$refCold $refGrad $valueFraction" >> "${dataFile}.in"
+ done
+
+ # create lock file to pass control to OF
+ touch ${lockFile}
+}
+
+
+# tutorial case employs the 'initByExternalOption', so we need to provide
+# the initial values
+init
+
+
+totalWait=0
+step=0
+while [ 1 ]; do
+ if [ -f $lockFile ]; then
+ log "found lock file ${lockFile} - waiting"
+ ((totalWait += waitSec))
+ if [ $totalWait -gt $timeOut ]; then
+ log "timeout"
+ break
+ else
+ sleep $waitSec
+ fi
+ else
+ totalWait=0
+ ((step++))
+ log "step $step"
+ log "lock not present - taking control"
+
+ log "sleeping for $waitSec secs to simulate external process"
+ sleep $waitSec
+
+ log "creating ${dataFile}.in"
+
+ awk '{if( $1 != "#" ){print $2+1 " 0 1"}}' ${dataFile}.out > ${dataFile}.in
+
+ log "creating lock file ${lockFile}"
+ touch ${lockFile}
+ fi
+done
+
+log "done"
+
+
+# ----------------------------------------------------------------- end-of-file
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/controlDict b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/controlDict
new file mode 100644
index 0000000000000000000000000000000000000000..afe4591501362f5fd49092722ff1f3fe28c7eb5e
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/controlDict
@@ -0,0 +1,48 @@
+/*--------------------------------*- 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 controlDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+application buoyantSimpleFoam;
+
+startFrom startTime;
+
+startTime 0;
+
+stopAt endTime;
+
+endTime 100;
+
+deltaT 1;
+
+writeControl timeStep;
+
+writeInterval 10;
+
+purgeWrite 0;
+
+writeFormat ascii;
+
+writePrecision 6;
+
+writeCompression off;
+
+timeFormat general;
+
+timePrecision 6;
+
+runTimeModifiable true;
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/decomposeParDict b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/decomposeParDict
new file mode 100644
index 0000000000000000000000000000000000000000..9165c030940a7593525d345371ad8611c5f45726
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/decomposeParDict
@@ -0,0 +1,29 @@
+/*--------------------------------*- 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;
+ location "system";
+ object decomposeParDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+numberOfSubdomains 4;
+
+method simple;
+
+simpleCoeffs
+{
+ n ( 2 2 1 );
+ delta 0.001;
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/fvSchemes b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/fvSchemes
new file mode 100644
index 0000000000000000000000000000000000000000..c52c053c84844fb84137797f741b112943bcd03a
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/fvSchemes
@@ -0,0 +1,67 @@
+/*--------------------------------*- 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 fvSchemes;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+ddtSchemes
+{
+ default steadyState;
+}
+
+gradSchemes
+{
+ default Gauss linear;
+}
+
+divSchemes
+{
+ default none;
+ div(phi,U) bounded Gauss limitedLinear 0.2;
+ div(phi,K) bounded Gauss limitedLinear 0.2;
+ div(phi,h) bounded Gauss limitedLinear 0.2;
+ div(phi,k) bounded Gauss limitedLinear 0.2;
+ div(phi,epsilon) bounded Gauss limitedLinear 0.2;
+ div(phi,omega) bounded Gauss limitedLinear 0.2;
+ div((muEff*dev2(T(grad(U))))) Gauss linear;
+}
+
+laplacianSchemes
+{
+ default none;
+ laplacian(muEff,U) Gauss linear orthogonal;
+ laplacian(Dp,p_rgh) Gauss linear orthogonal;
+ laplacian(alphaEff,h) Gauss linear orthogonal;
+ laplacian(DkEff,k) Gauss linear orthogonal;
+ laplacian(DepsilonEff,epsilon) Gauss linear orthogonal;
+ laplacian(DomegaEff,omega) Gauss linear orthogonal;
+}
+
+interpolationSchemes
+{
+ default linear;
+}
+
+snGradSchemes
+{
+ default orthogonal;
+}
+
+fluxRequired
+{
+ default no;
+ p_rgh;
+}
+
+
+// ************************************************************************* //
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/fvSolution b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/fvSolution
new file mode 100644
index 0000000000000000000000000000000000000000..d30cdf20b496e354128a273418811f504df1abed
--- /dev/null
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/externalCoupledCavity/system/fvSolution
@@ -0,0 +1,77 @@
+/*--------------------------------*- 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;
+ location "system";
+ object fvSolution;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+solvers
+{
+ p_rgh
+ {
+ solver GAMG;
+ tolerance 1e-7;
+ relTol 0.01;
+
+ smoother DICGaussSeidel;
+
+ cacheAgglomeration true;
+ nCellsInCoarsestLevel 10;
+ agglomerator faceAreaPair;
+ mergeLevels 1;
+ }
+
+ "(U|h|k|epsilon|omega)"
+ {
+ solver PBiCG;
+ preconditioner DILU;
+ tolerance 1e-8;
+ relTol 0.1;
+ }
+}
+
+SIMPLE
+{
+ momentumPredictor yes;
+ nNonOrthogonalCorrectors 0;
+ pRefCell 0;
+ pRefValue 0;
+
+ residualControl
+ {
+ p_rgh 1e-2;
+ U 1e-3;
+ h 1e-3;
+
+ // possibly check turbulence fields
+ "(k|epsilon|omega)" 1e-3;
+ }
+}
+
+relaxationFactors
+{
+ fields
+ {
+ rho 1.0;
+ p_rgh 0.7;
+ }
+ equations
+ {
+ U 0.3;
+ h 0.3;
+ "(k|epsilon|omega)" 0.7;
+ }
+}
+
+
+// ************************************************************************* //