summaryrefslogtreecommitdiff
path: root/examples/laminar/cavity2d
diff options
context:
space:
mode:
authorAdrian Kummerlaender2019-06-24 14:43:36 +0200
committerAdrian Kummerlaender2019-06-24 14:43:36 +0200
commit94d3e79a8617f88dc0219cfdeedfa3147833719d (patch)
treec1a6894679563e271f5c6ea7a17fa3462f7212a3 /examples/laminar/cavity2d
downloadgrid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.tar
grid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.tar.gz
grid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.tar.bz2
grid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.tar.lz
grid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.tar.xz
grid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.tar.zst
grid_refinement_openlb-94d3e79a8617f88dc0219cfdeedfa3147833719d.zip
Initialize at openlb-1-3
Diffstat (limited to 'examples/laminar/cavity2d')
-rw-r--r--examples/laminar/cavity2d/parallel/Makefile105
-rw-r--r--examples/laminar/cavity2d/parallel/cavity2d.cpp324
-rw-r--r--examples/laminar/cavity2d/parallel/cavity2d.xml44
-rw-r--r--examples/laminar/cavity2d/parallel/definitions.mk30
-rw-r--r--examples/laminar/cavity2d/parallel/description_cavity2d.xml345
-rw-r--r--examples/laminar/cavity2d/parallel/module.mk29
-rw-r--r--examples/laminar/cavity2d/sequential/Makefile105
-rw-r--r--examples/laminar/cavity2d/sequential/cavity2d.cpp230
-rw-r--r--examples/laminar/cavity2d/sequential/cavity2d.xml44
-rw-r--r--examples/laminar/cavity2d/sequential/definitions.mk30
-rw-r--r--examples/laminar/cavity2d/sequential/description_cavity2d.xml345
-rw-r--r--examples/laminar/cavity2d/sequential/module.mk29
12 files changed, 1660 insertions, 0 deletions
diff --git a/examples/laminar/cavity2d/parallel/Makefile b/examples/laminar/cavity2d/parallel/Makefile
new file mode 100644
index 0000000..a953954
--- /dev/null
+++ b/examples/laminar/cavity2d/parallel/Makefile
@@ -0,0 +1,105 @@
+# 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
+
+include definitions.mk
+
+include $(ROOT)/global.mk
+
+OBJECTS := $(foreach file, $(SRC), $(PWD)/$(file:.cpp=.o))
+DEPS := $(foreach file, $(SRC), $(PWD)/$(file:.cpp=.d))
+
+###########################################################################
+## all
+
+all : depend compile 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/*.*
+
+cleanobj:
+ @echo Clean object files
+ @rm -f $(OBJECTS)
+
+cleandep:
+ @echo Clean dependencies files
+ @rm -f $(DEPS)
+
+cleanbuild:
+ @cd $(ROOT); \
+ $(MAKE) cleanlib;
+
+###########################################################################
+## update lib
+
+$(ROOT)/$(LIBDIR)/lib$(LIB).a :
+ @cd $(ROOT); \
+ $(MAKE) all
+
+###########################################################################
+## link
+
+link: $(OUTPUT)
+
+$(OUTPUT): $(OBJECTS) $(ROOT)/$(LIBDIR)/lib$(LIB).a
+ @echo Link $@
+ $(CXX) $(foreach file, $(SRC), $(file:.cpp=.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/laminar/cavity2d/parallel/cavity2d.cpp b/examples/laminar/cavity2d/parallel/cavity2d.cpp
new file mode 100644
index 0000000..9fcc143
--- /dev/null
+++ b/examples/laminar/cavity2d/parallel/cavity2d.cpp
@@ -0,0 +1,324 @@
+/* Lattice Boltzmann sample, written in C++, using the OpenLB
+ * library
+ *
+ * Copyright (C) 2006 - 2012 Mathias J. Krause, Jonas Fietz,
+ * Jonas Latt, Jonas Kratzke
+ * 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.
+ */
+
+/* cavity2d.cpp:
+ * This example illustrates a flow in a cuboid, lid-driven cavity.
+ * It also shows how to use the XML parameter files and has an
+ * example description file for OpenGPI. This version is for parallel
+ * use. A version for sequential use is also available.
+ */
+
+
+#include "olb2D.h"
+#ifndef OLB_PRECOMPILED // Unless precompiled version is used,
+#include "olb2D.hh" // include full template code
+#endif
+#include <vector>
+#include <cmath>
+#include <iostream>
+
+using namespace olb;
+using namespace olb::descriptors;
+using namespace olb::graphics;
+using namespace olb::util;
+using namespace std;
+
+typedef double T;
+#define DESCRIPTOR D2Q9<>
+
+void prepareGeometry( UnitConverter<T,DESCRIPTOR> const& converter,
+ SuperGeometry2D<T>& superGeometry ) {
+ OstreamManager clout( std::cout,"prepareGeometry" );
+ clout << "Prepare Geometry ..." << std::endl;
+
+
+ superGeometry.rename( 0,2 );
+ superGeometry.rename( 2,1,1,1 );
+ superGeometry.clean();
+
+ T eps = converter.getConversionFactorLength();
+ Vector<T,2> extend( T( 1 ) + 2*eps, 2*eps );
+ Vector<T,2> origin( T() - eps, T( 1 ) - eps );
+ IndicatorCuboid2D<T> lid( extend, origin );
+ // Set material number for lid
+ superGeometry.rename( 2,3,1,lid );
+
+ // 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.getStatistics().print();
+ clout << "Prepare Geometry ... OK" << std::endl;
+}
+
+void prepareLattice( UnitConverter<T,DESCRIPTOR> const& converter,
+ SuperLattice2D<T, DESCRIPTOR>& sLattice,
+ Dynamics<T, DESCRIPTOR>& bulkDynamics,
+ sOnLatticeBoundaryCondition2D<T,DESCRIPTOR>& sBoundaryCondition,
+ SuperGeometry2D<T>& superGeometry ) {
+
+ OstreamManager clout( std::cout,"prepareLattice" );
+ clout << "Prepare Lattice ..." << std::endl;
+
+ const T omega = converter.getLatticeRelaxationFrequency();
+
+ // link lattice with dynamics for collision step
+
+ // Material=0 -->do nothing
+ sLattice.defineDynamics( superGeometry, 0, &instances::getNoDynamics<T, DESCRIPTOR>() );
+
+ // Material=1 -->bulk dynamics
+ sLattice.defineDynamics( superGeometry, 1, &bulkDynamics );
+
+ // Material=2,3 -->bulk dynamics, velocity boundary
+ sLattice.defineDynamics( superGeometry, 2, &bulkDynamics );
+ sLattice.defineDynamics( superGeometry, 3, &bulkDynamics );
+ sBoundaryCondition.addVelocityBoundary( superGeometry, 2, omega );
+ sBoundaryCondition.addVelocityBoundary( superGeometry, 3, omega );
+
+ clout << "Prepare Lattice ... OK" << std::endl;
+}
+
+void setBoundaryValues( UnitConverter<T,DESCRIPTOR> const& converter,
+ SuperLattice2D<T, DESCRIPTOR>& sLattice,
+ int iT, SuperGeometry2D<T>& superGeometry ) {
+
+ if ( iT==0 ) {
+ // set initial values: v = [0,0]
+ AnalyticalConst2D<T,T> rhoF( 1 );
+ std::vector<T> velocity( 2,T() );
+ AnalyticalConst2D<T,T> uF( velocity );
+
+ auto bulkIndicator = superGeometry.getMaterialIndicator({1, 2, 3});
+ sLattice.iniEquilibrium( bulkIndicator, rhoF, uF );
+ sLattice.defineRhoU( bulkIndicator, rhoF, uF );
+
+ // set non-zero velocity for upper boundary cells
+ velocity[0] = converter.getCharLatticeVelocity();
+ AnalyticalConst2D<T,T> u( velocity );
+ sLattice.defineU( superGeometry, 3, u );
+
+ // Make the lattice ready for simulation
+ sLattice.initialize();
+ }
+}
+
+void getResults( SuperLattice2D<T, DESCRIPTOR>& sLattice,
+ UnitConverter<T,DESCRIPTOR> const& converter, int iT, Timer<T>* timer,
+ const T logT, const T maxPhysT, const T imSave, const T vtkSave,
+ std::string filenameGif, std::string filenameVtk,
+ const int timerPrintMode,
+ const int timerTimeSteps, SuperGeometry2D<T>& superGeometry, bool converged ) {
+
+ OstreamManager clout( std::cout,"getResults" );
+
+ SuperVTMwriter2D<T> vtmWriter( filenameVtk );
+
+
+ if ( iT==0 ) {
+ // Writes the geometry, cuboid no. and rank no. as vti file for visualization
+ SuperLatticeGeometry2D<T, DESCRIPTOR> geometry( sLattice, superGeometry );
+ SuperLatticeCuboid2D<T, DESCRIPTOR> cuboid( sLattice );
+ SuperLatticeRank2D<T, DESCRIPTOR> rank( sLattice );
+ vtmWriter.write( geometry );
+ vtmWriter.write( cuboid );
+ vtmWriter.write( rank );
+ vtmWriter.createMasterFile();
+ }
+
+ // Get statistics
+ if ( iT%converter.getLatticeTime( logT )==0 || converged ) {
+ sLattice.getStatistics().print( iT, converter.getPhysTime( iT ) );
+ }
+
+ if ( iT%timerTimeSteps==0 || converged ) {
+ timer->print( iT,timerPrintMode );
+ }
+
+ // Writes the VTK files
+ if ( ( iT%converter.getLatticeTime( vtkSave )==0 && iT>0 ) || converged ) {
+ SuperLatticePhysVelocity2D<T,DESCRIPTOR> velocity( sLattice, converter );
+ SuperLatticePhysPressure2D<T,DESCRIPTOR> pressure( sLattice, converter );
+ vtmWriter.addFunctor( velocity );
+ vtmWriter.addFunctor( pressure );
+ vtmWriter.write( iT );
+ }
+
+ // Writes the Gif files
+ if ( ( iT%converter.getLatticeTime( imSave )==0 && iT>0 ) || converged ) {
+ SuperLatticePhysVelocity2D<T,DESCRIPTOR> velocity( sLattice, converter );
+ SuperEuklidNorm2D<T,DESCRIPTOR> normVel( velocity );
+ BlockReduction2D2D<T> planeReduction( normVel, 600, BlockDataSyncMode::ReduceOnly );
+ // write output of velocity as JPEG
+ heatmap::write(planeReduction, iT);
+ }
+
+ // Output for x-velocity along y-position at the last time step
+ if ( iT == converter.getLatticeTime( maxPhysT ) || converged ) {
+ // Gives access to velocity information on lattice
+ SuperLatticePhysVelocity2D<T, DESCRIPTOR> velocityField( sLattice, converter );
+ // Interpolation functor with velocityField information
+ AnalyticalFfromSuperF2D<T> interpolation( velocityField, true, 1 );
+
+ Vector<int,17> y_coord( {128, 125, 124, 123, 122, 109, 94, 79, 64, 58, 36, 22, 13, 9, 8, 7, 0} );
+ // Ghia, Ghia and Shin, 1982: "High-Re Solutions for Incompressible Flow Using the Navier-Stokes Equations and a Multigrid Method"; Table 1
+ Vector<T,17> vel_ghia_RE1000( { 1.0, 0.65928, 0.57492, 0.51117, 0.46604,
+ 0.33304, 0.18719, 0.05702,-0.06080,-0.10648,
+ -0.27805,-0.38289,-0.29730,-0.22220,-0.20196,
+ -0.18109, 0.0
+ } );
+ Vector<T,17> vel_ghia_RE100( {1.0, 0.84123, 0.78871, 0.73722, 0.68717,
+ 0.23151, 0.00332,-0.13641,-0.20581,-0.21090,
+ -0.15662,-0.10150,-0.06434,-0.04775,-0.04192,
+ -0.03717, 0.0
+ } );
+ Vector<T,17> vel_simulation;
+
+ // Gnuplot interface to create plots
+ static Gnuplot<T> gplot( "centerVelocityX" );
+ // Define comparison values
+ Vector<T,17> comparison = vel_ghia_RE1000;
+
+ for ( int nY = 0; nY < 17; ++nY ) {
+ // 17 data points evenly distributed between 0 and 1 (height)
+ T position[2] = {0.5, y_coord[nY]/128.0};
+ T velocity[2] = {T(), T()};
+ // Interpolate velocityField at "position" and save it in "velocity"
+ interpolation( velocity, position );
+ // Save value of velocity (in x-direction) in "vel_simulation" for every position "nY"
+ vel_simulation[nY] = velocity[0];
+ // Set data for plot output
+ gplot.setData( position[1], {vel_simulation[nY],comparison[nY]}, {"simulated","Ghia"} );
+ }
+ // Create PNG file
+ gplot.writePNG();
+ // Console output with results
+ clout << "absoluteErrorL2(line)=" << ( vel_simulation - comparison ).norm() / 17. << "; relativeErrorL2(line)=" << ( vel_simulation - comparison ).norm() / comparison.norm() << std::endl;
+ }
+}
+
+
+
+int main( int argc, char* argv[] ) {
+
+ // === 1st Step: Initialization ===
+ olbInit( &argc, &argv );
+ OstreamManager clout( std::cout,"main" );
+
+ string fName( "cavity2d.xml" );
+ XMLreader config( fName );
+
+ std::string olbdir, outputdir;
+ config["Application"]["OlbDir"].read( olbdir );
+ config["Output"]["OutputDir"].read( outputdir );
+ singleton::directories().setOlbDir( olbdir );
+ singleton::directories().setOutputDir( outputdir );
+
+ UnitConverter<T,DESCRIPTOR>* converter = createUnitConverter<T,DESCRIPTOR>( config );
+ // Prints the converter log as console output
+ converter->print();
+ // Writes the converter log in a file
+ converter->write("cavity2d");
+
+ int N = converter->getLatticeLength(1) + 1; // number of voxels in x,y,z direction
+ Timer<T>* timer = createTimer<T>( config, *converter, N*N );
+
+
+ T logT = config["Output"]["Log"]["SaveTime"].get<T>();
+ T imSave = config["Output"]["VisualizationImages"]["SaveTime"].get<T>();
+ T vtkSave = config["Output"]["VisualizationVTK"]["SaveTime"].get<T>();
+ T maxPhysT = config["Application"]["PhysParameters"]["PhysMaxTime"].get<T>();
+ int timerSkipType = config["Output"]["Timer"]["SkipType"].get<T>();
+ int timerPrintMode = config["Output"]["Timer"]["PrintMode"].get<int>();
+ int timerTimeSteps = 1;
+
+ if ( timerSkipType == 0 ) {
+ timerTimeSteps = converter->getLatticeTime( 1. /*config["Output"]["Timer"]["PhysTime"].get<T>()*/ );
+ } else {
+// config["Output"]["Timer"]["TimeSteps"].read( timerTimeSteps );
+ }
+
+ std::string filenameGif = config["Output"]["VisualizationImages"]["Filename"].get<std::string>();
+ std::string filenameVtk = config["Output"]["VisualizationVTK"]["Filename"].get<std::string>();
+
+ // === 2rd Step: Prepare Geometry ===
+ Vector<T,2> extend( 1,1 );
+ Vector<T,2> origin( 0,0 );
+ IndicatorCuboid2D<T> cuboid( extend, origin );
+
+#ifdef PARALLEL_MODE_MPI
+ CuboidGeometry2D<T> cuboidGeometry( cuboid, converter->getConversionFactorLength(), singleton::mpi().getSize() );
+#else
+ CuboidGeometry2D<T> cuboidGeometry( cuboid, converter->getConversionFactorLength(), 7 );
+#endif
+
+ cuboidGeometry.print();
+
+ HeuristicLoadBalancer<T> loadBalancer( cuboidGeometry );
+ SuperGeometry2D<T> superGeometry( cuboidGeometry, loadBalancer, 2 );
+ prepareGeometry( *converter, superGeometry );
+
+ // === 3rd Step: Prepare Lattice ===
+
+ SuperLattice2D<T, DESCRIPTOR> sLattice( superGeometry );
+
+ ConstRhoBGKdynamics<T, DESCRIPTOR> bulkDynamics (
+ converter->getLatticeRelaxationFrequency(),
+ instances::getBulkMomenta<T,DESCRIPTOR>()
+ );
+
+ sOnLatticeBoundaryCondition2D<T,DESCRIPTOR> sBoundaryCondition( sLattice );
+ createInterpBoundaryCondition2D<T,DESCRIPTOR,ConstRhoBGKdynamics<T,DESCRIPTOR> > ( sBoundaryCondition );
+
+ prepareLattice( *converter, sLattice, bulkDynamics, sBoundaryCondition, superGeometry );
+
+ // === 4th Step: Main Loop with Timer ===
+ int interval = converter->getLatticeTime( 1 /*config["Application"]["ConvergenceCheck"]["interval"].get<T>()*/ );
+ T epsilon = 1e-3; //config["Application"]["ConvergenceCheck"]["residuum"].get<T>();
+ util::ValueTracer<T> converge( interval, epsilon );
+
+ timer->start();
+ for ( int iT=0; iT <= converter->getLatticeTime( maxPhysT ); ++iT ) {
+ if ( converge.hasConverged() ) {
+ clout << "Simulation converged." << endl;
+ getResults( sLattice, *converter, iT, timer, logT, maxPhysT, imSave, vtkSave, filenameGif, filenameVtk,
+ timerPrintMode, timerTimeSteps, superGeometry, converge.hasConverged() );
+ break;
+ }
+ // === 5th Step: Definition of Initial and Boundary Conditions ===
+ setBoundaryValues( *converter, sLattice, iT, superGeometry );
+ // === 6th Step: Collide and Stream Execution ===
+ sLattice.collideAndStream();
+ // === 7th Step: Computation and Output of the Results ===
+ getResults( sLattice, *converter, iT, timer, logT, maxPhysT, imSave, vtkSave, filenameGif, filenameVtk,
+ timerPrintMode, timerTimeSteps, superGeometry, converge.hasConverged() );
+ converge.takeValue( sLattice.getStatistics().getAverageEnergy(), true );
+ }
+ timer->stop();
+ timer->printSummary();
+ delete converter;
+ delete timer;
+}
diff --git a/examples/laminar/cavity2d/parallel/cavity2d.xml b/examples/laminar/cavity2d/parallel/cavity2d.xml
new file mode 100644
index 0000000..b810246
--- /dev/null
+++ b/examples/laminar/cavity2d/parallel/cavity2d.xml
@@ -0,0 +1,44 @@
+<Param>
+ <Application>
+ <Name>cavity2d</Name>
+ <dim>2</dim>
+ <OlbDir>../../</OlbDir>
+ <Discretization>
+ <Resolution>128</Resolution>
+ <LatticeRelaxationTime>0.5384</LatticeRelaxationTime>
+ </Discretization>
+ <PhysParameters>
+ <PhysMaxTime>100</PhysMaxTime>
+ <CharPhysLength>1</CharPhysLength>
+ <CharPhysVelocity>1</CharPhysVelocity>
+ <PhysViscosity>0.001</PhysViscosity>
+ <PhysDensity>1</PhysDensity>
+ </PhysParameters>
+ <ConvergenceCheck>
+ <interval>1</interval>
+ <residuum>1e-3</residuum>
+ </ConvergenceCheck>
+ </Application>
+ <Output>
+ <OutputDir>./tmp/</OutputDir>
+ <MultiOutput>false</MultiOutput>
+ <Log>
+ <Filename>cavity2d.log</Filename>
+ <SaveTime>1</SaveTime>
+ </Log>
+ <VisualizationVTK>
+ <Filename>cavity2dvtk</Filename>
+ <SaveTime>1</SaveTime>
+ </VisualizationVTK>
+ <VisualizationImages>
+ <Filename>cavity2dimage</Filename>
+ <SaveTime>5</SaveTime>
+ </VisualizationImages>
+ <Timer>
+ <PrintMode>0</PrintMode>
+ <SkipType>0</SkipType>
+ <PhysTime>1</PhysTime>
+ <PrintSummary>true</PrintSummary>
+ </Timer>
+ </Output>
+</Param>
diff --git a/examples/laminar/cavity2d/parallel/definitions.mk b/examples/laminar/cavity2d/parallel/definitions.mk
new file mode 100644
index 0000000..84ffdca
--- /dev/null
+++ b/examples/laminar/cavity2d/parallel/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 := cavity2d.cpp
+OUTPUT := cavity2d
diff --git a/examples/laminar/cavity2d/parallel/description_cavity2d.xml b/examples/laminar/cavity2d/parallel/description_cavity2d.xml
new file mode 100644
index 0000000..63874e1
--- /dev/null
+++ b/examples/laminar/cavity2d/parallel/description_cavity2d.xml
@@ -0,0 +1,345 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<description xmlns="http://numhpc.math.kit.edu">
+ <version>0.1</version>
+ <block>
+ <name>Application</name>
+ <displayname>Application: Cavity 2D</displayname>
+ <enabled>true</enabled>
+ <key>
+ <name>Name</name>
+ <enabled>true</enabled>
+ <type>text</type>
+ <default>cavity2d</default>
+ <info>Name of the application</info>
+ </key>
+ <key>
+ <name>dim</name>
+ <displayname>Dimension</displayname>
+ <enabled>true</enabled>
+ <type>spinbox</type>
+ <default>2</default>
+ <min>2</min>
+ <max>2</max>
+ <info>Dimension of the domain</info>
+ </key>
+ <key>
+ <name>OlbDir</name>
+ <enabled>true</enabled>
+ <type>file</type>
+ <default>../../</default>
+ <info>Path to OpenLB directory</info>
+ </key>
+ <block>
+ <name>DiscParam</name>
+ <displayname>Discretization Parameters</displayname>
+ <enabled>true</enabled>
+ <key>
+ <name>latticeL</name>
+ <displayname>Lattice Length [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>0.0078125</default>
+ <info>
+ Length of a lattice cell in meter (proportional to Knudsen number)
+ (*obligatory)
+ </info>
+ </key>
+ <key>
+ <name>latticeU</name>
+ <displayname>Lattice Velocity</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>0.1</default>
+ <info>
+ Dimensionless lattice velocity (proportional to Mach number)
+ </info>
+ </key>
+ </block>
+ <block>
+ <name>PhysParam</name>
+ <displayname>Physical Parameters</displayname>
+ <enabled>true</enabled>
+ <key>
+ <name>MaxTime</name>
+ <displayname>MaxTime [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>15</default>
+ <info>
+ Maximal simulation time in seconds
+ </info>
+ </key>
+ <key>
+ <name>charL</name>
+ <displayname>Characteristical Length [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>1</default>
+ <info>Characteristical length in meter</info>
+ </key>
+ <key>
+ <name>charU</name>
+ <displayname>Characteristical Velocity [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>1</default>
+ <info>Characteristical speed in m/s</info>
+ </key>
+ <key>
+ <name>viscosityType</name>
+ <displayname>Describe viscosity by</displayname>
+ <enabled>true</enabled>
+ <type>combobox</type>
+ <defaultlist>
+ <item>Kinematic viscosity</item>
+ <item>Reynolds-Number</item>
+ </defaultlist>
+ <default>Kinematic viscosity</default>
+ <dep>
+ <value>Kinematic viscosity</value>
+ <target>
+ <targetblock>Application</targetblock>
+ <targetblock>PhysParam</targetblock>
+ <targetkey>charNu</targetkey>
+ <action>
+ <enablekey>true</enablekey>
+ </action>
+ </target>
+ <target>
+ <targetblock>Application</targetblock>
+ <targetblock>PhysParam</targetblock>
+ <targetkey>Re</targetkey>
+ <action>
+ <enablekey>false</enablekey>
+ </action>
+ </target>
+ </dep>
+ <dep>
+ <value>Reynolds-Number</value>
+ <target>
+ <targetblock>Application</targetblock>
+ <targetblock>PhysParam</targetblock>
+ <targetkey>Re</targetkey>
+ <action>
+ <enablekey>true</enablekey>
+ </action>
+ </target>
+ <target>
+ <targetblock>Application</targetblock>
+ <targetblock>PhysParam</targetblock>
+ <targetkey>charNu</targetkey>
+ <action>
+ <enablekey>false</enablekey>
+ </action>
+ </target>
+ </dep>
+ <info>Choose, whether you want to specify either characteristical kinematic viscosity or Reynolds-Number.</info>
+ </key>
+ <key>
+ <name>charNu</name>
+ <displayname>Characteristical Viscosity [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>0.001</default>
+ <info>
+ Kinematic viscosity in m^2/s
+ </info>
+ </key>
+ <key>
+ <name>Re</name>
+ <displayname>Reynolds-Number</displayname>
+ <enabled>false</enabled>
+ <type>decimal</type>
+ <default>100</default>
+ <info>
+ Reynolds number
+ </info>
+ </key>
+ <key>
+ <name>charRho</name>
+ <displayname>Characteristical Density [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>1</default>
+ <info>
+ Density factor rho in kg/m^d. As average latticeRho is always around 1, specify the average physical density here.
+ At some point latticeRho can be multplied by this factor to get the local physical density.
+ </info>
+ </key>
+ <key>
+ <name>charPressure</name>
+ <displayname>Characteristical Pressure [Si]</displayname>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>0</default>
+ <info>
+ This additive pressure constant in Pa is added to the relative pressure result of the computation
+ to get the absolute value.
+ </info>
+ </key>
+ </block>
+ </block>
+ <block>
+ <name>Output</name>
+ <displayname>Output Settings</displayname>
+ <enabled>true</enabled>
+ <key>
+ <name>OutputDir</name>
+ <enabled>true</enabled>
+ <type>file</type>
+ <default>./tmp/</default>
+ <info>Directory for output data</info>
+ </key>
+ <key>
+ <name>MultiOutput</name>
+ <displayname>Multi-Output Mode</displayname>
+ <enabled>true</enabled>
+ <type>checkbox</type>
+ <default>false</default>
+ <info>Chooses whether output will be activated per program (false) or per mpi process (true)</info>
+ </key>
+ <block>
+ <name>Log</name>
+ <displayname>Logging</displayname>
+ <enabled>true</enabled>
+ <key>
+ <name>Filename</name>
+ <enabled>true</enabled>
+ <type>file</type>
+ <default>cavity2d.log</default>
+ <info>Converter information will be stored in this file.</info>
+ </key>
+ <key>
+ <name>SaveTime</name>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>0.1</default>
+ <info>Time intervall for console output</info>
+ </key>
+ </block>
+ <block>
+ <name>VisualizationVTK</name>
+ <enabled>true</enabled>
+ <key>
+ <name>Filename</name>
+ <enabled>true</enabled>
+ <type>file</type>
+ <default>cavity2dvtk</default>
+ <info>No info</info>
+ </key>
+ <key>
+ <name>SaveTime</name>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>1</default>
+ <info>No info</info>
+ </key>
+ </block>
+ <block>
+ <name>VisualizationImages</name>
+ <enabled>true</enabled>
+ <key>
+ <name>Filename</name>
+ <enabled>true</enabled>
+ <type>file</type>
+ <default>cavity2dimage</default>
+ <info>No info</info>
+ </key>
+ <key>
+ <name>SaveTime</name>
+ <enabled>true</enabled>
+ <type>decimal</type>
+ <default>1</default>
+ <info>No info</info>
+ </key>
+ </block>
+ <block>
+ <name>Timer</name>
+ <enabled>true</enabled>
+ <key>
+ <name>PrintMode</name>
+ <displayname>Mode of Output</displayname>
+ <enabled>true</enabled>
+ <type>combobox</type>
+ <defaultlist>
+ <item value="0">csv-style</item>
+ <item value="1">one-line</item>
+ <item value="2">two-line-layout</item>
+ </defaultlist>
+ <default>0</default>
+ <info>Displays timer informations about current calculation with different output modes.</info>
+ </key>
+ <key>
+ <name>SkipType</name>
+ <displayname>Skip output by</displayname>
+ <enabled>true</enabled>
+ <type>combobox</type>
+ <defaultlist>
+ <item value="0">Physical time</item>
+ <item value="1">Time steps</item>
+ </defaultlist>
+ <default>0</default>
+ <dep>
+ <value>0</value>
+ <target>
+ <targetblock>Output</targetblock>
+ <targetblock>Timer</targetblock>
+ <targetkey>PhysTime</targetkey>
+ <action>
+ <enablekey>true</enablekey>
+ </action>
+ </target>
+ <target>
+ <targetblock>Output</targetblock>
+ <targetblock>Timer</targetblock>
+ <targetkey>TimeSteps</targetkey>
+ <action>
+ <enablekey>false</enablekey>
+ </action>
+ </target>
+ </dep>
+ <dep>
+ <value>1</value>
+ <target>
+ <targetblock>Output</targetblock>
+ <targetblock>Timer</targetblock>
+ <targetkey>PhysTime</targetkey>
+ <act