Initialize at openlb-1-3

4 files changed, 690 insertions, 0 deletions

diff --git a/examples/thermal/squareCavity3d/Makefile b/examples/thermal/squareCavity3d/Makefile
new file mode 100644
index 0000000..4cf2fcd
--- /dev/null
+++ b/examples/thermal/squareCavity3d/Makefile
@@ -0,0 +1,113 @@
+#  This file is part of the OpenLB library
+#
+#  Copyright (C) 2007 Mathias Krause
+#  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.
+
+
+###########################################################################
+###########################################################################
+## DEFINITIONS TO BE CHANGED
+
+ROOT            := ../../..
+SRC             :=
+OUTPUT          := squareCavity3d
+
+###########################################################################
+## definitions
+
+include $(ROOT)/global.mk
+
+OBJECTS    := $(foreach file, $(SRC) $(OUTPUT), $(PWD)/$(file).o)
+DEPS       := $(foreach file, $(SRC) $(OUTPUT), $(PWD)/$(file).d)
+
+###########################################################################
+## all
+
+all : depend compile updatelib link
+
+
+###########################################################################
+## dependencies
+
+depend : $(DEPS)
+
+$(PWD)/%.d : %.cpp
+	@echo Create dependencies for $<
+	@$(SHELL) -ec '$(CXX) -M $(CXXFLAGS) $(IDIR) $< \
+                       | sed -e "s!$*\.o!$(PWD)\/$*\.o!1" > .tmpfile; \
+                       cp -f .tmpfile $@;'
+
+###########################################################################
+## compile
+
+compile : $(OBJECTS)
+
+$(PWD)/%.o: %.cpp
+	@echo Compile $<
+	$(CXX) $(CXXFLAGS) $(IDIR) -c $< -o $@
+
+###########################################################################
+## clean
+
+clean : cleanrub cleanobj cleandep
+
+cleanrub:
+	@echo Clean rubbish files
+	@rm -f *~ core .tmpfile tmp/*.* $(OUTPUT)
+	@rm -f tmp/vtkData/*.* tmp/vtkData/data/*.* tmp/imageData/*.* tmp/gnuplotData/*.* tmp/gnuplotData/data/*.*  line.ghia.txt
+
+cleanobj:
+	@echo Clean object files
+	@rm -f $(OBJECTS)
+
+cleandep:
+	@echo Clean dependencies files
+	@rm -f $(DEPS)
+
+cleanbuild:
+	@echo Clean olb main
+	@cd $(ROOT); \
+	 $(MAKE) cleanbuild;
+
+###########################################################################
+## update lib
+
+updatelib :
+	@cd $(ROOT); \
+	 $(MAKE) all;
+
+###########################################################################
+## link
+
+link: $(OUTPUT)
+
+$(OUTPUT): $(OBJECTS) $(ROOT)/$(LIBDIR)/lib$(LIB).a
+	@echo Link $@
+	$(CXX) $(foreach file, $(SRC), $(file).o) $@.o $(LDFLAGS) -L$(ROOT)/$(LIBDIR) -l$(LIB) -lz -o $@
+
+###########################################################################
+## include dependencies
+
+ifneq "$(strip $(wildcard *.d))" ""
+   include $(foreach file,$(DEPS),$(file))
+endif
+
+###########################################################################
+###########################################################################
diff --git a/examples/thermal/squareCavity3d/definitions.mk b/examples/thermal/squareCavity3d/definitions.mk
new file mode 100644
index 0000000..2c7527f
--- /dev/null
+++ b/examples/thermal/squareCavity3d/definitions.mk
@@ -0,0 +1,30 @@
+#  This file is part of the OpenLB library
+#
+#  Copyright (C) 2007 Mathias Krause
+#  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.
+
+
+###########################################################################
+###########################################################################
+## DEFINITIONS TO BE CHANGED
+
+ROOT            := ../../..
+SRC             := squareCavity3d.cpp
+OUTPUT          := squareCavity3d
diff --git a/examples/thermal/squareCavity3d/module.mk b/examples/thermal/squareCavity3d/module.mk
new file mode 100644
index 0000000..1190482
--- /dev/null
+++ b/examples/thermal/squareCavity3d/module.mk
@@ -0,0 +1,29 @@
+#  This file is part of the OpenLB library
+#
+#  Copyright (C) 2017 Markus Mohrhard
+#  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.
+
+current_dir := $(dir $(word $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST)))
+
+include global.mk
+include rules.mk
+include $(addsuffix definitions.mk, $(current_dir))
+
+$(eval $(call sample,$(current_dir)$(OUTPUT),$(addprefix $(current_dir), $(SRC))))
diff --git a/examples/thermal/squareCavity3d/squareCavity3d.cpp b/examples/thermal/squareCavity3d/squareCavity3d.cpp
new file mode 100644
index 0000000..81d5028
--- /dev/null
+++ b/examples/thermal/squareCavity3d/squareCavity3d.cpp
@@ -0,0 +1,518 @@
+/*  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.
+ */
+
+// natural convection of air in a square cavity in 3D
+
+#include "olb3D.h"
+#include "olb3D.hh"   // use only generic version!
+
+using namespace olb;
+using namespace olb::descriptors;
+using namespace olb::graphics;
+using namespace std;
+
+typedef double T;
+
+#define NSDESCRIPTOR D3Q19<FORCE>
+#define TDESCRIPTOR D3Q7<VELOCITY>
+
+// Parameters for the simulation setup
+T Ra = 1e3;  // Rayleigh-Zahl
+const T Pr = 0.71; // Prandtl-Zahl
+
+T lx;
+
+int N = 64; // resolution of the model
+
+const T maxPhysT = 1e4;   // max. simulation time in s, SI unit
+const T epsilon = 1.e-3;  // precision of the convergence (residuum)
+
+const T Tcold = 275.15;
+const T Thot = 285.15;
+const T Tmean = (Tcold + Thot) / 2.0;
+
+/// Values from the literature studies from Davis
+T LitVelocity3[] = { 3.649, 3.696, 1.013 };
+T LitPosition3[] = { 0.813, 0.178 };
+T LitVelocity4[] = { 16.178, 19.617, 1.212 };
+T LitPosition4[] = { 0.823, 0.119 };
+T LitVelocity5[] = { 34.730, 68.590, 1.975 };
+T LitPosition5[] = { 0.855, 0.066 };
+T LitVelocity6[] = { 64.530, 219.36, 3.400 };
+T LitPosition6[] = { 0.850, 0.036 };
+T LitNusselt3 = 1.117;
+T LitNusselt4 = 2.238;
+T LitNusselt5 = 4.509;
+T LitNusselt6 = 8.817;
+
+/// Compute the nusselt number at the left wall
+T computeNusselt(SuperGeometry3D<T>& superGeometry,
+                 SuperLattice3D<T, NSDESCRIPTOR>& NSlattice,
+                 SuperLattice3D<T, TDESCRIPTOR>& ADlattice)
+{
+  int voxel = 0, material = 0;
+  T T_x = 0, T_xplus1 = 0, T_xplus2 = 0;
+  T q = 0;
+
+  for (int iC = 0; iC < NSlattice.getLoadBalancer().size(); iC++) {
+    int ny = NSlattice.getBlockLattice(iC).getNy();
+
+    int iX = 0;
+    int iZ = 1;
+
+    for (int iY = 0; iY < ny; ++iY) {
+      material = superGeometry.getBlockGeometry(iC).getMaterial(iX,iY,iZ);
+
+      T_x = ADlattice.getBlockLattice(iC).get(iX,iY,iZ).computeRho();
+      T_xplus1 = ADlattice.getBlockLattice(iC).get(iX+1,iY,iZ).computeRho();
+      T_xplus2 = ADlattice.getBlockLattice(iC).get(iX+2,iY,iZ).computeRho();
+
+      if ( material == 2 ) {
+        q += (3.0*T_x - 4.0*T_xplus1 + 1.0*T_xplus2)/2.0*N;
+        voxel++;
+      }
+    }
+  }
+
+#ifdef PARALLEL_MODE_MPI
+  singleton::mpi().reduceAndBcast(q, MPI_SUM);
+  singleton::mpi().reduceAndBcast(voxel, MPI_SUM);
+#endif
+
+  return q / (T)voxel;
+}
+
+/// Stores geometry information in form of material numbers
+void prepareGeometry(SuperGeometry3D<T>& superGeometry,
+                     ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter)
+{
+
+  OstreamManager clout(std::cout,"prepareGeometry");
+  clout << "Prepare Geometry ..." << std::endl;
+
+  superGeometry.rename(0,4);
+
+  std::vector<T> extend(3,T());
+  extend[0] = lx;
+  extend[1] = lx;
+  extend[2] = 3.0 * converter.getPhysLength(1);
+  std::vector<T> origin(3,T());
+  origin[0] = converter.getPhysLength(1);
+  origin[1] = 0.5*converter.getPhysLength(1);
+  origin[2] = 0.0;
+  IndicatorCuboid3D<T> cuboid2(extend, origin);
+
+  superGeometry.rename(4,1,cuboid2);
+
+  std::vector<T> extendwallleft(3,T(0));
+  extendwallleft[0] = converter.getPhysLength(1);
+  extendwallleft[1] = lx;
+  extendwallleft[2] = 0.1;
+  std::vector<T> originwallleft(3,T(0));
+  originwallleft[0] = 0.0;
+  originwallleft[1] = 0.0;
+  originwallleft[2] = 0.0;
+  IndicatorCuboid3D<T> wallleft(extendwallleft, originwallleft);
+
+  std::vector<T> extendwallright(3,T(0));
+  extendwallright[0] = converter.getPhysLength(1);
+  extendwallright[1] = lx;
+  extendwallright[2] = 0.1;
+  std::vector<T> originwallright(3,T(0));
+  originwallright[0] = lx+converter.getPhysLength(1);
+  originwallright[1] = 0.0;
+  originwallright[2] = 0.0;
+  IndicatorCuboid3D<T> wallright(extendwallright, originwallright);
+
+  superGeometry.rename(4,2,1,wallleft);
+  superGeometry.rename(4,3,1,wallright);
+
+
+  /// 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,
+                     SuperLattice3D<T, NSDESCRIPTOR>& NSlattice,
+                     SuperLattice3D<T, TDESCRIPTOR>& ADlattice,
+                     Dynamics<T, NSDESCRIPTOR> &bulkDynamics,
+                     Dynamics<T, TDESCRIPTOR>& advectionDiffusionBulkDynamics,
+                     sOnLatticeBoundaryCondition3D<T,NSDESCRIPTOR>& NSboundaryCondition,
+                     sOnLatticeBoundaryCondition3D<T,TDESCRIPTOR>& TboundaryCondition,
+                     SuperGeometry3D<T>& superGeometry )
+{
+
+  OstreamManager clout(std::cout,"prepareLattice");
+  clout << "Prepare Lattice ..." << std::endl;
+
+  T omega  = converter.getLatticeRelaxationFrequency();
+  T Tomega  = converter.getLatticeThermalRelaxationFrequency();
+
+  /// define lattice Dynamics
+  ADlattice.defineDynamics(superGeometry, 0, &instances::getNoDynamics<T, TDESCRIPTOR>());
+  NSlattice.defineDynamics(superGeometry, 0, &instances::getNoDynamics<T, NSDESCRIPTOR>());
+
+  ADlattice.defineDynamics(superGeometry.getMaterialIndicator({1, 2, 3}), &advectionDiffusionBulkDynamics);
+  ADlattice.defineDynamics(superGeometry, 4, &instances::getBounceBack<T, TDESCRIPTOR>());
+
+  NSlattice.defineDynamics(superGeometry.getMaterialIndicator({1, 2, 3}), &bulkDynamics);
+  NSlattice.defineDynamics(superGeometry, 4, &instances::getBounceBack<T, NSDESCRIPTOR>());
+
+  /// sets boundary
+  TboundaryCondition.addTemperatureBoundary(superGeometry.getMaterialIndicator({2, 3}), Tomega);
+  NSboundaryCondition.addVelocityBoundary(superGeometry.getMaterialIndicator({2, 3}), omega);
+
+  /// define initial conditions
+  AnalyticalConst3D<T,T> rho(1.);
+  AnalyticalConst3D<T,T> u0(0.0, 0.0, 0.0);
+  AnalyticalConst3D<T,T> T_cold(converter.getLatticeTemperature(Tcold));
+  AnalyticalConst3D<T,T> T_hot(converter.getLatticeTemperature(Thot));
+  AnalyticalConst3D<T,T> T_mean(converter.getLatticeTemperature(Tmean));
+
+  /// 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);
+
+  ADlattice.defineRho(superGeometry, 1, T_mean);
+  ADlattice.iniEquilibrium(superGeometry, 1, T_mean, 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);
+
+  /// Make the lattice ready for simulation
+  NSlattice.initialize();
+  ADlattice.initialize();
+
+  clout << "Prepare Lattice ... OK" << std::endl;
+}
+
+void setBoundaryValues(ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter,
+                       SuperLattice3D<T, NSDESCRIPTOR>& NSlattice,
+                       SuperLattice3D<T, TDESCRIPTOR>& ADlattice,
+                       int iT, SuperGeometry3D<T>& superGeometry)
+{
+
+  // nothing to do here
+
+}
+
+void getResults(ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> &converter,
+                SuperLattice3D<T, NSDESCRIPTOR>& NSlattice,
+                SuperLattice3D<T, TDESCRIPTOR>& ADlattice, int iT,
+                SuperGeometry3D<T>& superGeometry,
+                Timer<T>& timer,
+                bool converged)
+{
+
+  OstreamManager clout(std::cout,"getResults");
+
+  SuperVTMwriter3D<T> vtkWriter("thermalNaturalConvection3D");
+  SuperLatticeGeometry3D<T, NSDESCRIPTOR> geometry(NSlattice, superGeometry);
+  SuperLatticePhysVelocity3D<T, NSDESCRIPTOR> velocity(NSlattice, converter);
+  SuperLatticePhysPressure3D<T, NSDESCRIPTOR> pressure(NSlattice, converter);
+  SuperLatticePhysTemperature3D<T, NSDESCRIPTOR,TDESCRIPTOR> temperature(ADlattice, converter);
+  vtkWriter.addFunctor( geometry );
+  vtkWriter.addFunctor( pressure );
+  vtkWriter.addFunctor( velocity );
+  vtkWriter.addFunctor( temperature );
+
+  AnalyticalFfromSuperF3D<T> interpolation(velocity, true);
+
+  const int vtkIter = 2000.;
+
+  if (iT == 0) {
+    /// Writes the geometry, cuboid no. and rank no. as vti file for visualization
+    SuperLatticeCuboid3D<T, NSDESCRIPTOR> cuboid(NSlattice);
+    SuperLatticeRank3D<T, NSDESCRIPTOR> rank(NSlattice);
+    vtkWriter.write(cuboid);
+    vtkWriter.write(rank);
+
+    vtkWriter.createMasterFile();
+  }
+
+  /// Writes the VTK files
+  if (iT%vtkIter == 0 || converged) {
+
+    timer.update(iT);
+    timer.printStep();
+
+    /// NSLattice statistics console output
+    NSlattice.getStatistics().print(iT,converter.getPhysTime(iT));
+    /// ADLattice statistics console output
+    ADlattice.getStatistics().print(iT,converter.getPhysTime(iT));
+
+    vtkWriter.write(iT);
+    const double a[3] = {0, 0, 1.};
+    BlockReduction3D2D<T> planeReduction(temperature, a);
+    BlockGifWriter<T> gifWriter;
+    gifWriter.write(planeReduction, Tcold*0.98, Thot*1.02, iT, "temperature");
+
+    SuperEuklidNorm3D<T, NSDESCRIPTOR> normVel( velocity );
+    BlockReduction3D2D<T> planeReduction2(normVel, {0, 0, 1});
+    BlockGifWriter<T> gifWriter2;
+    gifWriter2.write( planeReduction2, iT, "velocity" );
+
+  }
+
+  if ( converged ) {
+
+    T nusselt = computeNusselt(superGeometry, NSlattice, ADlattice);
+
+    /// Initialize vectors for data output
+    T xVelocity[3] = { T() };
+    T outputVelX[3] = { T() };
+    T yVelocity[3] = { T() };
+    T outputVelY[3] = { T() };
+    const int outputSize = 512;
+    Vector<T, outputSize> velX;
+    Vector<T, outputSize> posX;
+    Vector<T, outputSize> velY;
+    Vector<T, outputSize> posY;
+
+    /// loop for the resolution of the cavity at x = lx/2 in yDirection and vice versa
+    for (int n = 0; n < outputSize; ++n) {
+      T yPosition[3] = { lx / 2, lx * n / (T) outputSize, lx / N * 2 / 2 };
+      T xPosition[3] = { lx * n / (T) outputSize, lx / 2, lx / N * 2 / 2 };
+
+      /// Interpolate xVelocity at x = lx/2 for each yPosition
+      interpolation(xVelocity, yPosition);
+      interpolation(yVelocity, xPosition);
+      /// Store the interpolated values to compare them among each other in order to detect the maximum
+      velX[n] = xVelocity[0];
+      posY[n] = yPosition[1];
+      velY[n] = yVelocity[1];
+      posX[n] = xPosition[0];
+
+      /// Initialize output with the corresponding velocities and positions at the origin
+      if (n == 0) {
+        outputVelX[0] = velX[0];
+        outputVelX[1] = posY[0];
+        outputVelY[0] = velY[0];
+        outputVelY[1] = posX[0];
+      }
+      /// look for the maximum velocity in xDirection and the corresponding position in yDirection
+      if (n > 0 && velX[n] > outputVelX[0]) {
+        outputVelX[0] = velX[n];
+        outputVelX[1] = posY[n];
+      }
+      /// look for the maximum velocity in yDirection and the corresponding position in xDirection
+      if (n > 0 && velY[n] > outputVelY[0]) {
+        outputVelY[0] = velY[n];
+        outputVelY[1] = posX[n];
+      }
+    }
+
+    // compare to De Vahl Davis' benchmark solutions
+    clout << "Comparison against De Vahl Davis (1983):" << endl;
+    if (Ra == 1e3) {
+      clout << "xVelocity in yDir=" <<  outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity3[0] - outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity3[0]) << endl;
+      clout << "yVelocity in xDir=" <<  outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity3[1] - outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity3[1]) << endl;
+      clout << "yMaxVel / xMaxVel="  <<  outputVelY[0] / outputVelX[0] << "; error(rel)=" << (T) fabs((LitVelocity3[2] - outputVelY[0] / outputVelX[0])  / LitVelocity3[2]) << endl;
+      clout << "yCoord of xMaxVel=" <<  outputVelX[1]/lx << "; error(rel)=" << (T) fabs((LitPosition3[0] - outputVelX[1] / lx) / LitPosition3[0]) << endl;
+      clout << "xCoord of yMaxVel=" <<   outputVelY[1]/lx << "; error(rel)=" << (T) fabs((LitPosition3[1] - outputVelY[1] / lx) / LitPosition3[1]) << endl;
+      clout << "Nusselt=" <<  nusselt << "; error(rel)=" << (T) fabs((LitNusselt3 - nusselt) / nusselt) << endl;
+    }
+    else if (Ra == 1e4) {
+      clout << "xVelocity in yDir=" <<  outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity4[0] - outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity4[0]) << endl;
+      clout << "yVelocity in xDir=" <<  outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity4[1] - outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity4[1]) << endl;
+      clout << "yMaxVel / xMaxVel="  <<  outputVelY[0] / outputVelX[0] << "; error(rel)=" << (T) fabs((LitVelocity4[2] - outputVelY[0] / outputVelX[0])  / LitVelocity4[2]) << endl;
+      clout << "yCoord of xMaxVel=" <<  outputVelX[1]/lx << "; error(rel)=" << (T) fabs((LitPosition4[0] - outputVelX[1] / lx) / LitPosition4[0]) << endl;
+      clout << "xCoord of yMaxVel=" <<   outputVelY[1]/lx << "; error(rel)=" << (T) fabs((LitPosition4[1] - outputVelY[1] / lx) / LitPosition4[1]) << endl;
+      clout << "Nusselt=" <<  nusselt << "; error(rel)=" << (T) fabs((LitNusselt4 - nusselt) / nusselt) << endl;
+    }
+    else if (Ra == 1e5) {
+      clout << "xVelocity in yDir=" <<  outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity5[0] - outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity5[0]) << endl;
+      clout << "yVelocity in xDir=" <<  outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity5[1] - outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity5[1]) << endl;
+      clout << "yMaxVel / xMaxVel="  <<  outputVelY[0] / outputVelX[0] << "; error(rel)=" << (T) fabs((LitVelocity5[2] - outputVelY[0] / outputVelX[0])  / LitVelocity5[2]) << endl;
+      clout << "yCoord of xMaxVel=" <<  outputVelX[1]/lx << "; error(rel)=" << (T) fabs((LitPosition5[0] - outputVelX[1] / lx) / LitPosition5[0]) << endl;
+      clout << "xCoord of yMaxVel=" <<   outputVelY[1]/lx << "; error(rel)=" << (T) fabs((LitPosition5[1] - outputVelY[1] / lx) / LitPosition5[1]) << endl;
+      clout << "Nusselt=" <<  nusselt << "; error(rel)=" << (T) fabs((LitNusselt5 - nusselt) / nusselt) << endl;
+    }
+    else if (Ra == 1e6) {
+      clout << "xVelocity in yDir=" <<  outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity6[0] - outputVelX[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity6[0]) << endl;
+      clout << "yVelocity in xDir=" <<  outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength() << "; error(rel)=" << (T) fabs((LitVelocity6[1] - outputVelY[0] / converter.getPhysThermalDiffusivity() * converter.getCharPhysLength()) / LitVelocity6[1]) << endl;
+      clout << "yMaxVel / xMaxVel="  <<  outputVelY[0] / outputVelX[0] << "; error(rel)=" << (T) fabs((LitVelocity6[2] - outputVelY[0] / outputVelX[0])  / LitVelocity6[2]) << endl;
+      clout << "yCoord of xMaxVel=" <<  outputVelX[1]/lx << "; error(rel)=" << (T) fabs((LitPosition6[0] - outputVelX[1] / lx) / LitPosition6[0]) << endl;
+      clout << "xCoord of yMaxVel=" <<   outputVelY[1]/lx << "; error(rel)=" << (T) fabs((LitPosition6[1] - outputVelY[1] / lx) / LitPosition6[1]) << endl;
+      clout << "Nusselt=" <<  nusselt << "; error(rel)=" << (T) fabs((LitNusselt6 - nusselt) / nusselt) << endl;
+    }
+  }
+}
+
+int main(int argc, char *argv[])
+{
+
+  /// === 1st Step: Initialization ===
+  OstreamManager clout(std::cout,"main");
+  olbInit(&argc, &argv);
+  singleton::directories().setOutputDir("./tmp/");
+
+  T tau = 0.9;
+
+  if (argc>=2) {
+    Ra = atof(argv[1]);
+  }
+
+  lx  = pow(Ra * 15.126e-6 * 15.126e-6 / Pr / 9.81 / (Thot - Tcold) / 0.00341, (T) 1/3);  // length of the square
+  T charU = 1.0 / lx /( Pr * 25.684e-3 / 15.126e-6 / 1.0 * 1.0 / 25.684e-3);
+
+  if (Ra==1e3) {
+    charU *= LitVelocity3[1];
+    N = 64;
+  }
+  if (Ra==1e4) {
+    charU *= LitVelocity4[1];
+    N = 128;
+  }
+  if (Ra==1e5) {
+    charU *= LitVelocity5[1];
+    N = 256;
+  }
+  if (Ra==1e6) {
+    charU *= LitVelocity6[1];
+    N = 512;
+  }
+
+  ThermalUnitConverter<T, NSDESCRIPTOR, TDESCRIPTOR> converter(
+    (T) lx / N,
+    (T) (tau - 0.5) / descriptors::invCs2<T,NSDESCRIPTOR>() * pow((lx/N),2) / 15.126e-6,
+    (T) lx,
+    (T) charU,
+    (T) 15.126e-6,
+    (T) 1.0,
+    (T) 25.684e-3,
+    (T) Pr * 25.684e-3 / 15.126e-6 / 1.0,
+    (T) 0.00341,
+    (T) Tcold,
+    (T) Thot
+  );
+  converter.print();
+
+  /// === 2nd Step: Prepare Geometry ===
+  std::vector<T> extend(3,T());
+  extend[0] = lx + 2*converter.getPhysLength(1);
+  extend[1] = lx + converter.getPhysLength(1);
+  extend[2] = 2.*converter.getPhysLength(1);
+  std::vector<T> origin(3,T());
+  IndicatorCuboid3D<T> cuboid(extend, origin);
+
+  /// Instantiation of an empty cuboidGeometry
+  CuboidGeometry3D<T> cuboidGeometry(cuboid, converter.getPhysDeltaX(), singleton::mpi().getSize());
+  cuboidGeometry.setPeriodicity(false, false, true);  // x, y, z
+
+  /// Instantiation of a loadBalancer
+  HeuristicLoadBalancer<T> loadBalancer(cuboidGeometry);
+
+  /// Instantiation of a superGeometry
+  SuperGeometry3D<T> superGeometry(cuboidGeometry, loadBalancer, 2);
+
+  prepareGeometry(superGeometry, converter);
+
+  /// === 3rd Step: Prepare Lattice ===
+
+  SuperLattice3D<T, TDESCRIPTOR> ADlattice(superGeometry);
+  SuperLattice3D<T, NSDESCRIPTOR> NSlattice(superGeometry);
+
+  sOnLatticeBoundaryCondition3D<T, NSDESCRIPTOR> NSboundaryCondition(NSlattice);
+  createLocalBoundaryCondition3D<T, NSDESCRIPTOR>(NSboundaryCondition);
+
+  sOnLatticeBoundaryCondition3D<T, TDESCRIPTOR> TboundaryCondition(ADlattice);
+  createAdvectionDiffusionBoundaryCondition3D<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, 0.0};
+
+  T boussinesqForcePrefactor = 9.81 / converter.getConversionFactorVelocity() * converter.getConversionFactorTime() *
+                               converter.getCharPhysTemperatureDifference() * converter.getPhysThermalExpansionCoefficient();
+
+  NavierStokesAdvectionDiffusionCouplingGenerator3D<T,NSDESCRIPTOR>
+  coupling(0, converter.getLatticeLength(lx), 0, converter.getLatticeLength(lx), 0, converter.getLatticeLength(lx),
+           boussinesqForcePrefactor, converter.getLatticeTemperature(Tcold), 1., dir);
+
+  NSlattice.addLatticeCoupling(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(6,epsilon);
+  for (int iT = 0; iT < converter.getLatticeTime(maxPhysT); ++iT) {
+
+    if (converge.hasConverged()) {
+      clout << "Simulation converged." << endl;
+      clout << "Time " << iT << "." << std::endl;
+
+      getResults(converter, NSlattice, ADlattice, iT, superGeometry, timer, converge.hasConverged());
+
+      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());
+    if (iT % 1000 == 0) {
+      converge.takeValue(computeNusselt(superGeometry, NSlattice, ADlattice),true);
+    }
+  }
+
+  timer.stop();
+  timer.printSummary();
+}