diff --git a/applications/solvers/heatTransfer/buoyantPimpleFoam/Make/options b/applications/solvers/heatTransfer/buoyantPimpleFoam/Make/options
index d3224df411..a9b16d2f25 100644
--- a/applications/solvers/heatTransfer/buoyantPimpleFoam/Make/options
+++ b/applications/solvers/heatTransfer/buoyantPimpleFoam/Make/options
@@ -1,4 +1,5 @@
 EXE_INC = \
+    -I../../compressible/rhoPimpleFoam \
     -I$(LIB_SRC)/finiteVolume/lnInclude \
     -I$(LIB_SRC)/meshTools/lnInclude \
     -I$(LIB_SRC)/sampling/lnInclude \
@@ -7,6 +8,8 @@ EXE_INC = \
     -I$(LIB_SRC)/thermophysicalModels/radiation/lnInclude \
     -I$(LIB_SRC)/TurbulenceModels/turbulenceModels/lnInclude \
     -I$(LIB_SRC)/TurbulenceModels/compressible/lnInclude \
+    -I$(LIB_SRC)/dynamicMesh/lnInclude \
+    -I$(LIB_SRC)/dynamicFvMesh/lnInclude \
     -I$(LIB_SRC)/regionFaModels\lnInclude
 
 EXE_LIBS = \
@@ -21,4 +24,7 @@ EXE_LIBS = \
     -lturbulenceModels \
     -lcompressibleTurbulenceModels \
     -latmosphericModels \
+    -ldynamicMesh \
+    -ldynamicFvMesh \
+    -ltopoChangerFvMesh \
     -lregionFaModels
diff --git a/applications/solvers/heatTransfer/buoyantPimpleFoam/buoyantPimpleFoam.C b/applications/solvers/heatTransfer/buoyantPimpleFoam/buoyantPimpleFoam.C
index 691916c17e..70595ebba3 100644
--- a/applications/solvers/heatTransfer/buoyantPimpleFoam/buoyantPimpleFoam.C
+++ b/applications/solvers/heatTransfer/buoyantPimpleFoam/buoyantPimpleFoam.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -30,8 +31,9 @@ Group
     grpHeatTransferSolvers
 
 Description
-    Transient solver for buoyant, turbulent flow of compressible fluids for
-    ventilation and heat-transfer.
+    Transient solver for buoyant, turbulent flow of compressible fluids
+    for ventilation and heat-transfer, with optional mesh motion
+    and mesh topology changes.
 
     Turbulence is modelled using a run-time selectable compressible RAS or
     LES model.
@@ -39,12 +41,16 @@ Description
 \*---------------------------------------------------------------------------*/
 
 #include "fvCFD.H"
+#include "dynamicFvMesh.H"
 #include "rhoThermo.H"
 #include "turbulentFluidThermoModel.H"
 #include "radiationModel.H"
+#include "CorrectPhi.H"
 #include "fvOptions.H"
 #include "pimpleControl.H"
 #include "pressureControl.H"
+#include "localEulerDdtScheme.H"
+#include "fvcSmooth.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -53,7 +59,8 @@ int main(int argc, char *argv[])
     argList::addNote
     (
         "Transient solver for buoyant, turbulent fluid flow"
-        " of compressible fluids, including radiation."
+        " of compressible fluids, including radiation,"
+        " with optional mesh motion and mesh topology changes."
     );
 
     #include "postProcess.H"
@@ -61,36 +68,105 @@ int main(int argc, char *argv[])
     #include "addCheckCaseOptions.H"
     #include "setRootCaseLists.H"
     #include "createTime.H"
-    #include "createMesh.H"
-    #include "createControl.H"
+    #include "createDynamicFvMesh.H"
+    #include "createDyMControls.H"
+    #include "initContinuityErrs.H"
     #include "createFields.H"
     #include "createFieldRefs.H"
-    #include "initContinuityErrs.H"
-    #include "createTimeControls.H"
-    #include "compressibleCourantNo.H"
-    #include "setInitialDeltaT.H"
+    #include "createRhoUfIfPresent.H"
 
     turbulence->validate();
 
+    if (!LTS)
+    {
+        #include "compressibleCourantNo.H"
+        #include "setInitialDeltaT.H"
+    }
+
     // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
     Info<< "\nStarting time loop\n" << endl;
 
     while (runTime.run())
     {
-        #include "readTimeControls.H"
-        #include "compressibleCourantNo.H"
-        #include "setDeltaT.H"
+        #include "readDyMControls.H"
+
+        // Store divrhoU from the previous mesh
+        // so that it can be mapped and used in correctPhi
+        // to ensure the corrected phi has the same divergence
+        autoPtr<volScalarField> divrhoU;
+        if (correctPhi)
+        {
+            divrhoU.reset
+            (
+                new volScalarField
+                (
+                    "divrhoU",
+                    fvc::div(fvc::absolute(phi, rho, U))
+                )
+            );
+        }
+
+        if (LTS)
+        {
+            #include "setRDeltaT.H"
+        }
+        else
+        {
+            #include "compressibleCourantNo.H"
+            #include "setDeltaT.H"
+        }
 
         ++runTime;
 
         Info<< "Time = " << runTime.timeName() << nl << endl;
 
-        #include "rhoEqn.H"
-
         // --- Pressure-velocity PIMPLE corrector loop
         while (pimple.loop())
         {
+            if (pimple.firstIter() || moveMeshOuterCorrectors)
+            {
+                // Store momentum to set rhoUf for introduced faces.
+                autoPtr<volVectorField> rhoU;
+                if (rhoUf.valid())
+                {
+                    rhoU.reset(new volVectorField("rhoU", rho*U));
+                }
+
+                // Do any mesh changes
+                mesh.update();
+
+                if (mesh.changing())
+                {
+                    gh = (g & mesh.C()) - ghRef;
+                    ghf = (g & mesh.Cf()) - ghRef;
+
+                    MRF.update();
+
+                    if (correctPhi)
+                    {
+                        // Calculate absolute flux
+                        // from the mapped surface velocity
+                        phi = mesh.Sf() & rhoUf();
+
+                        #include "correctPhi.H"
+
+                        // Make the fluxes relative to the mesh-motion
+                        fvc::makeRelative(phi, rho, U);
+                    }
+
+                    if (checkMeshCourantNo)
+                    {
+                        #include "meshCourantNo.H"
+                    }
+                }
+            }
+
+            if (pimple.firstIter() && !pimple.SIMPLErho())
+            {
+                #include "rhoEqn.H"
+            }
+
             #include "UEqn.H"
             #include "EEqn.H"
 
diff --git a/applications/solvers/heatTransfer/buoyantPimpleFoam/createFields.H b/applications/solvers/heatTransfer/buoyantPimpleFoam/createFields.H
index 22dc129a87..813d1c3240 100644
--- a/applications/solvers/heatTransfer/buoyantPimpleFoam/createFields.H
+++ b/applications/solvers/heatTransfer/buoyantPimpleFoam/createFields.H
@@ -1,3 +1,5 @@
+#include "createRDeltaT.H"
+
 Info<< "Reading thermophysical properties\n" << endl;
 
 autoPtr<rhoThermo> pThermo(rhoThermo::New(mesh));
diff --git a/applications/solvers/heatTransfer/buoyantPimpleFoam/pEqn.H b/applications/solvers/heatTransfer/buoyantPimpleFoam/pEqn.H
index 886f9c6a5f..733e97028d 100644
--- a/applications/solvers/heatTransfer/buoyantPimpleFoam/pEqn.H
+++ b/applications/solvers/heatTransfer/buoyantPimpleFoam/pEqn.H
@@ -28,6 +28,8 @@ MRF.makeRelative(fvc::interpolate(rho), phiHbyA);
 // Update the pressure BCs to ensure flux consistency
 constrainPressure(p_rgh, rho, U, phiHbyA, rhorAUf, MRF);
 
+fvc::makeRelative(phiHbyA, rho, U);
+
 fvScalarMatrix p_rghDDtEqn
 (
     fvc::ddt(rho) + psi*correction(fvm::ddt(p_rgh))
@@ -104,7 +106,15 @@ else
 
 rho = thermo.rho();
 
+// Correct rhoUf if the mesh is moving
+fvc::correctRhoUf(rhoUf, rho, U, phi);
+
 if (thermo.dpdt())
 {
     dpdt = fvc::ddt(p);
+
+    if (mesh.moving())
+    {
+        dpdt -= fvc::div(fvc::meshPhi(rho, U), p);
+    }
 }