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diff --git a/examples/thermal/rayleighBenard2d/rayleighBenard2d.cpp b/examples/thermal/rayleighBenard2d/rayleighBenard2d.cpp
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+/*  Lattice Boltzmann sample, written in C++, using the OpenLB
+ *  library
+ *
+ *  Copyright (C) 2008 Orestis Malaspinas
+ *  E-mail contact: info@openlb.net
+ *  The most recent release of OpenLB can be downloaded at
+ *  <http://www.openlb.net/>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public
+ *  License along with this program; if not, write to the Free
+ *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA  02110-1301, USA.
+ */
+
+/* rayleighBenard2d.cpp:
+ * Rayleigh-Benard convection rolls in 2D, simulated with
+ * the thermal LB model by Z. Guo e.a., between a hot plate at
+ * the bottom and a cold plate at the top.
+ */
+
+
+#include "olb2D.h"
+#include "olb2D.hh"   // use only generic version!
+
+using namespace olb;
+using namespace olb::descriptors;
+using namespace olb::graphics;
+using namespace std;
+
+typedef double T;
+
+#define NSDESCRIPTOR D2Q9<FORCE>
+#define TDESCRIPTOR D2Q5<VELOCITY>
+
+// Parameters for the simulation setup
+const T lx  = 2.;          // length of the channel
+const T ly  = 1.;          // height of the channel
+const int N = 10;         // resolution of the model
+const T Ra = 1e4;          // Rayleigh number
+const T Pr = 0.71;         // Prandtl number
+const T maxPhysT = 1000.; // max. simulation time in s, SI unit
+const T epsilon = 1.e-5;   // precision of the convergence (residuum)
+
+const T Thot = 274.15;     // temperature of the lower wall in Kelvin
+const T Tcold = 273.15;    // temperature of the fluid in Kelvin
+const T Tperturb = 1./5. * Tcold + 4./5. * Thot; // temperature of the perturbation
+
+/// Stores geometry information in form of material numbers
+void prepareGeometry(SuperGeometry2D<T>& superGeometry,
+                     ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter)
+{
+
+  OstreamManager clout(std::cout,"prepareGeometry");
+  clout << "Prepare Geometry ..." << std::endl;
+
+  superGeometry.rename(0,2);
+  superGeometry.rename(2,1,0,1);
+
+  std::vector<T> extend( 2, T(0) );
+  extend[0] = lx;
+  extend[1] = converter.getPhysLength(1);
+  std::vector<T> origin( 2, T(0) );
+  IndicatorCuboid2D<T> bottom(extend, origin);
+
+  origin[1] = ly-converter.getPhysLength(1);
+  IndicatorCuboid2D<T> top(extend, origin);
+
+  origin[0] = lx/2.;
+  origin[1] = converter.getPhysLength(1);
+  extend[0] = converter.getPhysLength(1);
+  extend[1] = converter.getPhysLength(1);
+  IndicatorCuboid2D<T> perturbation(extend, origin);
+
+  /// Set material numbers for bottom, top and pertubation
+  superGeometry.rename(2,2,1,bottom);
+  superGeometry.rename(2,3,1,top);
+  superGeometry.rename(1,4,perturbation);
+
+  /// Removes all not needed boundary voxels outside the surface
+  superGeometry.clean();
+  /// Removes all not needed boundary voxels inside the surface
+  superGeometry.innerClean();
+  superGeometry.checkForErrors();
+
+  superGeometry.print();
+
+  clout << "Prepare Geometry ... OK" << std::endl;
+}
+
+void prepareLattice( ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter,
+                     SuperLattice2D<T, NSDESCRIPTOR>& NSlattice,
+                     SuperLattice2D<T, TDESCRIPTOR>& ADlattice,
+                     Dynamics<T, NSDESCRIPTOR> &bulkDynamics,
+                     Dynamics<T, TDESCRIPTOR>& advectionDiffusionBulkDynamics,
+                     sOnLatticeBoundaryCondition2D<T,NSDESCRIPTOR>& NSboundaryCondition,
+                     sOnLatticeBoundaryCondition2D<T,TDESCRIPTOR>& TboundaryCondition,
+                     SuperGeometry2D<T>& superGeometry )
+{
+
+  OstreamManager clout(std::cout,"prepareLattice");
+
+  T Tomega  = converter.getLatticeThermalRelaxationFrequency();
+
+  /// define lattice Dynamics
+  clout << "defining dynamics" << endl;
+
+  ADlattice.defineDynamics(superGeometry, 0, &instances::getNoDynamics<T, TDESCRIPTOR>());
+  NSlattice.defineDynamics(superGeometry, 0, &instances::getNoDynamics<T, NSDESCRIPTOR>());
+
+  ADlattice.defineDynamics(superGeometry, 1, &advectionDiffusionBulkDynamics);
+  ADlattice.defineDynamics(superGeometry, 2, &advectionDiffusionBulkDynamics);
+  ADlattice.defineDynamics(superGeometry, 3, &advectionDiffusionBulkDynamics);
+  ADlattice.defineDynamics(superGeometry, 4, &advectionDiffusionBulkDynamics);
+  NSlattice.defineDynamics(superGeometry, 1, &bulkDynamics);
+  NSlattice.defineDynamics(superGeometry, 2, &instances::getBounceBack<T, NSDESCRIPTOR>());
+  NSlattice.defineDynamics(superGeometry, 3, &instances::getBounceBack<T, NSDESCRIPTOR>());
+  NSlattice.defineDynamics(superGeometry, 4, &bulkDynamics);
+
+  /// sets boundary
+  TboundaryCondition.addTemperatureBoundary(superGeometry, 2, Tomega);
+  TboundaryCondition.addTemperatureBoundary(superGeometry, 3, Tomega);
+
+  /// define initial conditions
+  AnalyticalConst2D<T,T> rho(1.);
+  AnalyticalConst2D<T,T> u0(0.0, 0.0);
+  AnalyticalConst2D<T,T> T_cold(converter.getLatticeTemperature(Tcold));
+  AnalyticalConst2D<T,T> T_hot(converter.getLatticeTemperature(Thot));
+  AnalyticalConst2D<T,T> T_perturb(converter.getLatticeTemperature(Tperturb));
+
+  /// for each material set Rho, U and the Equilibrium
+  NSlattice.defineRhoU(superGeometry, 1, rho, u0);
+  NSlattice.iniEquilibrium(superGeometry, 1, rho, u0);
+  NSlattice.defineRhoU(superGeometry, 2, rho, u0);
+  NSlattice.iniEquilibrium(superGeometry, 2, rho, u0);
+  NSlattice.defineRhoU(superGeometry, 3, rho, u0);
+  NSlattice.iniEquilibrium(superGeometry, 3, rho, u0);
+  NSlattice.defineRhoU(superGeometry, 4, rho, u0);
+  NSlattice.iniEquilibrium(superGeometry, 4, rho, u0);
+
+  ADlattice.defineRho(superGeometry, 1, T_cold);
+  ADlattice.iniEquilibrium(superGeometry, 1, T_cold, u0);
+  ADlattice.defineRho(superGeometry, 2, T_hot);
+  ADlattice.iniEquilibrium(superGeometry, 2, T_hot, u0);
+  ADlattice.defineRho(superGeometry, 3, T_cold);
+  ADlattice.iniEquilibrium(superGeometry, 3, T_cold, u0);
+  ADlattice.defineRho(superGeometry, 4, T_perturb);
+  ADlattice.iniEquilibrium(superGeometry, 4, T_perturb, u0);
+
+  /// Make the lattice ready for simulation
+  NSlattice.initialize();
+  ADlattice.initialize();
+
+  clout << "Prepare Lattice ... OK" << std::endl;
+}
+
+void setBoundaryValues(ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter,
+                       SuperLattice2D<T, NSDESCRIPTOR>& NSlattice,
+                       SuperLattice2D<T, TDESCRIPTOR>& ADlattice,
+                       int iT, SuperGeometry2D<T>& superGeometry)
+{
+  // nothing to do here
+}
+
+void getResults(ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter,
+                SuperLattice2D<T, NSDESCRIPTOR>& NSlattice,
+                SuperLattice2D<T, TDESCRIPTOR>& ADlattice, int iT,
+                SuperGeometry2D<T>& superGeometry,
+                Timer<T>& timer,
+                bool converged)
+{
+
+  OstreamManager clout(std::cout,"getResults");
+
+  SuperVTMwriter2D<T> vtkWriter("rayleighBenard2d");
+  SuperLatticePhysVelocity2D<T, NSDESCRIPTOR> velocity(NSlattice, converter);
+  SuperLatticePhysPressure2D<T, NSDESCRIPTOR> presure(NSlattice, converter);
+  SuperLatticePhysTemperature2D<T, NSDESCRIPTOR, TDESCRIPTOR> temperature(ADlattice, converter);
+  vtkWriter.addFunctor( presure );
+  vtkWriter.addFunctor( velocity );
+  vtkWriter.addFunctor( temperature );
+
+  const int saveIter = converter.getLatticeTime(10.0);
+
+  if (iT == 0) {
+    /// Writes the converter log file
+    // writeLogFile(converter,"rayleighBenard2d");
+
+    /// Writes the geometry, cuboid no. and rank no. as vti file for visualization
+    SuperLatticeGeometry2D<T, NSDESCRIPTOR> geometry(NSlattice, superGeometry);
+    SuperLatticeCuboid2D<T, NSDESCRIPTOR> cuboid(NSlattice);
+    SuperLatticeRank2D<T, NSDESCRIPTOR> rank(NSlattice);
+    vtkWriter.write(geometry);
+    vtkWriter.write(cuboid);
+    vtkWriter.write(rank);
+
+    vtkWriter.createMasterFile();
+  }
+
+  /// Writes the VTK files and prints statistics
+  if (iT%saveIter == 0 || converged) {
+    /// Timer console output
+    timer.update(iT);
+    timer.printStep();
+
+    /// Lattice statistics console output
+    NSlattice.getStatistics().print(iT,converter.getPhysTime(iT));
+
+    vtkWriter.write(iT);
+
+    BlockReduction2D2D<T> planeReduction(temperature, 600, BlockDataSyncMode::ReduceOnly);
+    BlockGifWriter<T> gifWriter;
+    gifWriter.write(planeReduction, Tcold-0.1, Thot+0.1, iT, "temperature");
+  }
+
+}
+
+int main(int argc, char *argv[])
+{
+
+  /// === 1st Step: Initialization ===
+  OstreamManager clout(std::cout,"main");
+  olbInit(&argc, &argv);
+  singleton::directories().setOutputDir("./tmp/");
+
+  ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> converter(
+    (T) 0.1/N, // physDeltaX
+    (T) 0.1 / (1e-5 / 0.1 * sqrt( Ra / Pr)) * 0.1 / N, // physDeltaT = charLatticeVelocity / charPhysVelocity * physDeltaX
+    (T) 0.1,  // charPhysLength
+    (T) 1e-5 / 0.1 * sqrt( Ra / Pr ), // charPhysVelocity
+    (T) 1e-5,  // physViscosity
+    (T) 1.0, // physDensity
+    (T) 0.03, // physThermalConductivity
+    (T) Pr * 0.03 / 1e-5 / 1.0,    // physSpecificHeatCapacity
+    (T) Ra * 1e-5 * 1e-5 / Pr / 9.81 / (Thot - Tcold) / pow(0.1, 3), // physThermalExpansionCoefficient
+    (T) Tcold, // charPhysLowTemperature
+    (T) Thot // charPhysHighTemperature
+  );
+  converter.print();
+
+  /// === 2nd Step: Prepare Geometry ===
+  std::vector<T> extend(2,T());
+  extend[0] = lx;
+  extend[1] = ly;
+  std::vector<T> origin(2,T());
+  IndicatorCuboid2D<T> cuboid(extend, origin);
+
+  /// Instantiation of a cuboidGeometry with weights
+#ifdef PARALLEL_MODE_MPI
+  const int noOfCuboids = singleton::mpi().getSize();
+#else
+  const int noOfCuboids = 7;
+#endif
+  CuboidGeometry2D<T> cuboidGeometry(cuboid, converter.getPhysDeltaX(), noOfCuboids);
+
+  cuboidGeometry.setPeriodicity(true, false);
+
+  HeuristicLoadBalancer<T> loadBalancer(cuboidGeometry);
+
+  SuperGeometry2D<T> superGeometry(cuboidGeometry, loadBalancer, 2);
+
+  prepareGeometry(superGeometry, converter);
+
+  /// === 3rd Step: Prepare Lattice ===
+
+  SuperLattice2D<T, TDESCRIPTOR> ADlattice(superGeometry);
+  SuperLattice2D<T, NSDESCRIPTOR> NSlattice(superGeometry);
+
+  sOnLatticeBoundaryCondition2D<T, NSDESCRIPTOR> NSboundaryCondition(NSlattice);
+  createLocalBoundaryCondition2D<T, NSDESCRIPTOR>(NSboundaryCondition);
+
+  sOnLatticeBoundaryCondition2D<T, TDESCRIPTOR> TboundaryCondition(ADlattice);
+  createAdvectionDiffusionBoundaryCondition2D<T, TDESCRIPTOR>(TboundaryCondition);
+
+  ForcedBGKdynamics<T, NSDESCRIPTOR> NSbulkDynamics(
+    converter.getLatticeRelaxationFrequency(),
+    instances::getBulkMomenta<T,NSDESCRIPTOR>());
+
+  AdvectionDiffusionBGKdynamics<T, TDESCRIPTOR> TbulkDynamics (
+    converter.getLatticeThermalRelaxationFrequency(),
+    instances::getAdvectionDiffusionBulkMomenta<T,TDESCRIPTOR>()
+  );
+
+  // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!//
+  // This coupling must be necessarily be put on the Navier-Stokes lattice!!
+  // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!//
+
+  std::vector<T> dir{0.0, 1.0};
+
+  T boussinesqForcePrefactor = 9.81 / converter.getConversionFactorVelocity() * converter.getConversionFactorTime() *
+    converter.getCharPhysTemperatureDifference() * converter.getPhysThermalExpansionCoefficient();
+
+  NavierStokesAdvectionDiffusionCouplingGenerator2D<T,NSDESCRIPTOR> coupling(0, converter.getLatticeLength(lx), 0, converter.getLatticeLength(ly), boussinesqForcePrefactor, converter.getLatticeTemperature(Tcold), 1., dir);
+
+  NSlattice.addLatticeCoupling(coupling, ADlattice);
+  NSlattice.addLatticeCoupling(superGeometry, 2, coupling, ADlattice);
+  NSlattice.addLatticeCoupling(superGeometry, 3, coupling, ADlattice);
+  NSlattice.addLatticeCoupling(superGeometry, 4, coupling, ADlattice);
+
+  prepareLattice(converter,
+                 NSlattice, ADlattice,
+                 NSbulkDynamics, TbulkDynamics,
+                 NSboundaryCondition, TboundaryCondition, superGeometry );
+
+  /// === 4th Step: Main Loop with Timer ===
+  Timer<T> timer(converter.getLatticeTime(maxPhysT), superGeometry.getStatistics().getNvoxel() );
+  timer.start();
+
+  util::ValueTracer<T> converge(converter.getLatticeTime(50.),epsilon);
+  for (int iT = 0; iT < converter.getLatticeTime(maxPhysT); ++iT) {
+
+    if (converge.hasConverged()) {
+      clout << "Simulation converged." << endl;
+      getResults(converter, NSlattice, ADlattice, iT, superGeometry, timer, converge.hasConverged());
+
+      clout << "Time " << iT << "." << std::endl;
+
+      break;
+    }
+
+    /// === 5th Step: Definition of Initial and Boundary Conditions ===
+    setBoundaryValues(converter, NSlattice, ADlattice, iT, superGeometry);
+
+    /// === 6th Step: Collide and Stream Execution ===
+    ADlattice.collideAndStream();
+    NSlattice.collideAndStream();
+
+    NSlattice.executeCoupling();
+
+    /// === 7th Step: Computation and Output of the Results ===
+    getResults(converter, NSlattice, ADlattice, iT, superGeometry, timer, converge.hasConverged());
+    converge.takeValue(ADlattice.getStatistics().getAverageEnergy(),true);
+  }
+
+  timer.stop();
+  timer.printSummary();
+}