Showcase for dense particle packing

apps/showcases/CMakeLists.txt

@@ -4,6 +4,7 @@ add_subdirectory( FluidizedBed )
 add_subdirectory( HeatConduction )
 add_subdirectory( LightRisingParticleInFluidAMR )
 add_subdirectory( Mixer )
+add_subdirectory( ParticlePacking )
 add_subdirectory( PegIntoSphereBed )
 if ( WALBERLA_BUILD_WITH_CODEGEN AND WALBERLA_BUILD_WITH_PYTHON )
 add_subdirectory( PhaseFieldAllenCahn )

apps/showcases/ParticlePacking/CMakeLists.txt

+waLBerla_link_files_to_builddir( *.cfg )
+
+if (WALBERLA_MESAPD_CONVEX_POLYHEDRON_AVAILABLE)
+   waLBerla_add_executable ( NAME ParticlePacking
+                             FILES ParticlePacking.cpp
+                             DEPENDS blockforest core mesa_pd postprocessing sqlite vtk )
+endif()
+

apps/showcases/ParticlePacking/DiameterDistribution.h

+//======================================================================================================================
+//
+//  This file is part of waLBerla. waLBerla 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 3 of
+//  the License, or (at your option) any later version.
+//
+//  waLBerla 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 waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
+//
+//! \file   DiameterDistribution.h
+//! \author Christoph Rettinger <christoph.rettinger@fau.de>
+//
+//======================================================================================================================
+
+#pragma once
+
+#include <random>
+
+#include "Utility.h"
+
+namespace walberla {
+namespace mesa_pd {
+
+
+class DiameterGenerator
+{
+public:
+   virtual real_t get() = 0;
+   virtual ~DiameterGenerator() = default;
+};
+
+class LogNormal: public DiameterGenerator
+{
+public:
+   LogNormal(real_t mu, real_t var, uint_t seed = 42)
+         : gen_(seed)
+   {
+      auto m = std::log(mu*mu/std::sqrt(var+mu*mu));
+      auto s = std::sqrt(log(var/(mu*mu) + 1_r));
+      dist_ = std::lognormal_distribution<> (m, s);
+   }
+
+   real_t get() override
+   {
+      return real_c(dist_(gen_));
+   }
+private:
+   std::mt19937 gen_;
+   std::lognormal_distribution<> dist_;
+};
+
+class Uniform: public DiameterGenerator
+{
+public:
+   Uniform(real_t diameter)
+         : diameter_(diameter)
+   { }
+
+   real_t get() override
+   {
+      return diameter_;
+   }
+private:
+   real_t diameter_;
+};
+
+class DiscreteSieving: public DiameterGenerator
+{
+public:
+   DiscreteSieving(std::vector<real_t> diameters, std::vector<real_t> massFractions, uint_t seed,
+                   real_t normalParticleVolume, real_t totalParticleMass = 1_r, real_t particleDensity = 1_r)
+         : diameters_(diameters), gen_(seed)
+   {
+      WALBERLA_CHECK_EQUAL(diameters.size(), massFractions.size(), "Number of entries in diameter and mass-fraction array has to be the same!");
+      WALBERLA_CHECK_FLOAT_EQUAL(real_t(1), std::accumulate(massFractions.begin(), massFractions.end(), real_t(0)), "Sum of mass fractions has to be 1!");
+      auto particleNumbers = transferMassFractionsToParticleNumbers(massFractions, diameters, normalParticleVolume, totalParticleMass, particleDensity);
+      std::string outString = "Discrete Sieving: Expected particle numbers per diameter: | ";
+      bool issueWarning = false;
+      for(const auto & p : particleNumbers){
+         issueWarning |= (p > 0_r && p < 1_r);
+         outString += std::to_string(int(p)) + " | ";
+      }
+      auto totalParticles = std::accumulate(particleNumbers.begin(), particleNumbers.end(), real_t(0));
+      outString += " -> total = " + std::to_string(int(totalParticles));
+      WALBERLA_LOG_INFO_ON_ROOT(outString);
+      if(issueWarning) WALBERLA_LOG_WARNING_ON_ROOT("Attention: The simulated particle mass is not enough to have at least a single particle of all size classes!");
+      dist_ = std::discrete_distribution<uint_t>(particleNumbers.begin(), particleNumbers.end());
+   }
+
+   real_t get() override
+   {
+      return diameters_[dist_(gen_)];
+   }
+private:
+   std::vector<real_t> diameters_;
+   std::mt19937 gen_;
+   std::discrete_distribution<uint_t> dist_;
+};
+
+
+class ContinuousSieving: public DiameterGenerator
+{
+public:
+   ContinuousSieving(std::vector<real_t> sieveSizes, std::vector<real_t> massFractions, uint_t seed,
+                     real_t normalParticleVolume, real_t totalParticleMass = 1_r, real_t particleDensity = 1_r)
+         :  gen_(seed)
+   {
+      WALBERLA_CHECK_EQUAL(sieveSizes.size(), massFractions.size()+1, "Number of entries in sieves has to be one larger than the mass-fraction array!");
+      WALBERLA_CHECK_FLOAT_EQUAL(real_t(1), std::accumulate(massFractions.begin(), massFractions.end(), real_t(0)), "Sum of mass fractions has to be 1!");
+
+      auto meanDiameters = getMeanDiametersFromSieveSizes(sieveSizes);
+      auto particleNumbers = transferMassFractionsToParticleNumbers(massFractions, meanDiameters, normalParticleVolume, totalParticleMass, particleDensity);
+      std::string outString = "Continuous Sieving: Expected particle numbers per diameter: | ";
+      bool issueWarning = false;
+      for(const auto & p : particleNumbers){
+         issueWarning |= (p > 0_r && p < 1_r);
+         outString += std::to_string(int(p)) + " | ";
+      }
+      auto totalParticles = std::accumulate(particleNumbers.begin(), particleNumbers.end(), real_t(0));
+      outString += " -> total = " + std::to_string(int(totalParticles));
+      WALBERLA_LOG_INFO_ON_ROOT(outString);
+      if(issueWarning) WALBERLA_LOG_WARNING_ON_ROOT("Attention: The simulated particle mass is not enough to have at least a single particle of all size classes!");
+      std::vector<real_t> logSieveSizes(sieveSizes.size(),0_r); // =  phi-scale -> uniformly distributed
+      for(uint_t i = 0; i < logSieveSizes.size(); ++i)
+      {
+         logSieveSizes[i] = - std::log2(sieveSizes[i]);
+      }
+
+      dist_ = std::piecewise_constant_distribution<real_t>(logSieveSizes.begin(), logSieveSizes.end(), particleNumbers.begin());
+   }
+
+   real_t get() override
+   {
+      return std::pow(2_r,-dist_(gen_)); //re-transfer from phi-scale to actual diameter
+   }
+private:
+   std::mt19937 gen_;
+   std::piecewise_constant_distribution<real_t> dist_;
+};
+
+
+} // namespace mesa_pd
+} // namespace walberla

apps/showcases/ParticlePacking/ParticlePacking.cfg

+ParticlePacking
+{
+    domainSetup periodic; // container, periodic
+    domainWidth 0.104; // m
+    domainHeight 1; // m
+
+    particleDensity 2650; // kg/m^3, 2500 (spheres), 2650 (real sediments);
+    ambientDensity 1000; // kg/m^3
+    gravitationalAcceleration 9.81; // m/s^2
+
+    particleDistribution SievingCurve; // size distribution, see 'Distribution' block for options
+    particleShape Mesh; // see 'Shape' block
+
+    limitVelocity -1; // m/s, negative switches limiting off
+    initialVelocity 1; // m/s
+    initialGenerationHeightRatioStart 0.1; // -
+    initialGenerationHeightRatioEnd 1; // -
+    generationSpacing 0.010; // m
+    scaleGenerationSpacingWithForm true;
+    generationHeightRatioStart 0.6; // -
+    generationHeightRatioEnd 1; // -
+
+    totalParticleMass 4; // kg
+
+    numBlocksPerDirection <3,3,1>;
+
+    visSpacing 0.01; // s
+    infoSpacing 0.01; // s
+    loggingSpacing 0.01; // s
+
+    terminalVelocity 1e-3; // m/s
+    terminalRelativeHeightChange 1e-5; // -
+    terminationCheckingSpacing 0.01; // s
+    minimalTerminalRunTime .0; // s, minimal runtime after generation & shaking
+
+    solver DEM; // particle simulation approach, see 'Solver' block for options
+
+    shaking true; // see 'Shaking' block
+
+    velocityDampingCoefficient 1e-3; // continuous reduction of velocity in last simulation phase
+
+    useHashGrids false;
+    particleSortingSpacing 1000; // time steps, non-positive values switch sorting off, performance optimization
+}
+
+Shaking
+{
+    amplitude 3e-4; // m
+    period 0.025; // s
+    duration 6.0; // s, duration of shaking AFTER creation of all particles
+    activeFromBeginning true;
+}
+
+Solver
+{
+    coefficientOfRestitution 0.1; // -
+    frictionCoefficient 0.5; // -
+    dt 5e-6; // s, time step size
+    DEM
+    {
+        collisionTime 20e-5; // s
+        poissonsRatio 0.22; // -
+    }
+
+    HCSITS
+    {
+        errorReductionParameter 0.8;
+        relaxationParameter 0.75;
+        numberOfIterations 10;
+        relaxationModel InelasticGeneralizedMaximumDissipationContact;
+    }
+}
+
+Distribution
+{
+    randomSeed 41; // if negative, seed is randomly chosen
+
+    Uniform{
+        diameter 11e-3; // m
+    }
+
+    LogNormal{
+        mu 1e-3; // m
+        variance 1e-7;
+    }
+
+    DiameterMassFractions
+    {
+        // from Schruff, 2016
+        //diameters 1.5e-3 2e-3 3e-3 4e-3 6e-3 8e-3 11e-3 16e-3 22e-3;
+        //massFractions .00 .00 1.00 .00 .00 .00 .00 .00 .00; // I, U
+        //massFractions .00 .00 .00 1.00 .00 .00 .00 .00 .00; // II, U
+        //massFractions .00 .00 .00 .00 1.00 .00 .00 .00 .00; // III, U
+        //massFractions .00 .00 .50 .00 .50 .00 .00 .00 .00; // IV, B
+        //massFractions .00 .00 .00 .50 .00 .50 .00 .00 .00; // V, B
+        //massFractions .00 .00 .00 .00 .00 .50 .00 .50 .00; // VI, B
+        //massFractions .00 .00 .25 .50 .25 .00 .00 .00 .00; // VII, T
+        //massFractions .00 .00 .00 .25 .50 .25 .00 .00 .00; // VIII, T
+        //massFractions .00 .00 .00 .00 .25 .50 .25 .00 .00; // IX, T
+        //massFractions .025 .050 .100 .200 .250 .200 .100 .050 .025; // X, LN
+
+        // Liang, 2015, discrete spheres (3,4,6,8,11,16,22 mm)
+        diameters 3e-3 4e-3 6e-3 8e-3 11e-3 16e-3 22e-3;
+        //massFractions 0 0 1 0 0 0 0; // A
+        //massFractions .0 .0 .21 .58 .21 0 0; // B
+        //massFractions .0 .06 .24 .4 .24 .06 .0; // C
+        //massFractions .04 .11 .22 .26 .22 .11 .04; // D
+        //massFractions .08 .13 .08 .06 .18 .29 .18; // E
+        massFractions .13 .21 .13 .06 .13 .21 .13; // F
+        //massFractions .18 .29 .18 .06 .08 .13 .08; // G
+    }
+
+    SievingCurve
+    {
+        // Frings, 2011, Verification, slightly truncated, table 2
+        //sieveSizes 0.063e-3 0.09e-3 0.125e-3 0.18e-3 0.25e-3 0.355e-3 0.5e-3 0.71e-3 1e-3 1.4e-3 2e-3 2.8e-3 4e-3 5.6e-3 8e-3 11.2e-3 16e-3 22.4e-3 31.5e-3 45e-3 63e-3;
+        //massFractions .00 .00 .01 .01 .05 .15 .12 .06 .03 .03 .03 .05 .06 .07 .07 .07 .06 .06 .04 .03; // case 45
+
+        // Lian, 2015, DigiPack, values from porosity report (Versuch3), in cylinder with diam 104mm
+        sieveSizes 2.8e-3 4e-3 5.6e-3 8e-3 11.2e-3 16e-3 22.4e-3 31.5e-3;
+        //massFractions 0 0 1 0 0 0 0; // A
+        //massFractions .0 .0 .21 .58 .21 0 0; // B
+        //massFractions .0 .06 .24 .4 .24 .06 .0; // C
+        //massFractions .04 .11 .22 .26 .22 .11 .04; // D
+        //massFractions .08 .13 .08 .06 .18 .29 .18; // E
+        massFractions .13 .21 .13 .06 .13 .21 .13; // F
+        //massFractions .18 .29 .18 .06 .08 .13 .08; // G
+
+        //massFractions 0 0 0 0 0 0 1; // D
+
+        useDiscreteForm false; // only use average sieving diameters
+    }
+}
+
+Shape
+{
+    scaleMode sieveLike; // sphereEquivalent, sieveLike
+
+    Sphere
+    {
+    }
+
+    Ellipsoid
+    {
+        semiAxes <50,5,1>; // will be scaled to obtain desired size
+    }
+
+    EquivalentEllipsoid
+    {
+        // specify either a mesh file or a folder containing mesh files ( have to be .obj files)
+        //path example_meshes/sediment_scan_0.obj;
+        path example_meshes;
+    }
+
+    EllipsoidFormDistribution
+    {
+        elongationMean 0.4;
+        elongationStdDev 0.2;
+        flatnessMean 0.4;
+        flatnessStdDev 0.2;
+    }
+
+    Mesh
+    {
+        // specify either a mesh file or a folder containing mesh files ( have to be .obj files)
+        //path example_meshes/sediment_scan_0.obj;
+        path example_meshes;
+    }
+
+    MeshFormDistribution
+    {
+        path example_meshes; // meshes used as basis, are then scaled to match size and form
+
+        elongationMean 0.4; //0.682;
+        elongationStdDev 0.2; //0.139;
+        flatnessMean 0.4; //0.65;
+        flatnessStdDev 0.2; //0.175;
+    }
+
+    UnscaledMeshesPerFraction
+    {
+        // expects subfolders 0, 1,... in given folder that contain a set of meshes
+        // those meshes are taken as is and not scaled during creation
+        // the mass fraction from Distribution/SievingCurve is used to determine the generation probabilities per fraction
+        folder meshes_collection_unscaled;
+    }
+}
+
+Evaluation
+{
+    vtkFolder vtk_out_container;
+    vtkFinalFolder vtk_files;
+
+    //Rhein, Frings, 2011, Verification, Table 2
+    histogramBins 200e-3 125e-3 90e-3 63e-3 45e-3 31.5e-3 22.4e-3 16e-3 11.2e-3 8e-3 5.6e-3 4e-3 2.8e-3 2e-3 1.4e-3 1e-3 0.71e-3 0.5e-3 0.355e-3 0.25e-3 0.18e-3 0.125e-3 0.09e-3 0.063e-3;
+
+    //for horizontal layer evaluation (only spheres)
+    porosityProfileFolder porosity_profiles;
+    layerHeight 1e-3; // m
+
+    sqlDBFileName db_ParticlePacking.sqlite;
+}

apps/showcases/ParticlePacking/Utility.h

+//======================================================================================================================
+//
+//  This file is part of waLBerla. waLBerla 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 3 of
+//  the License, or (at your option) any later version.
+//
+//  waLBerla 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 waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
+//
+//! \file   Utility.h
+//! \author Christoph Rettinger <christoph.rettinger@fau.de>
+//
+//======================================================================================================================
+
+#pragma once
+
+#include "mesa_pd/data/ParticleStorage.h"
+
+#include <iterator>
+#include <algorithm>
+#include <functional>
+
+namespace walberla {
+namespace mesa_pd {
+
+class ParticleAccessorWithShape : public data::ParticleAccessor
+{
+public:
+   ParticleAccessorWithShape(std::shared_ptr<data::ParticleStorage>& particleStorage)
+         : ParticleAccessor(particleStorage)
+   {}
+
+   walberla::real_t const & getInvMass(const size_t p_idx) const {return ps_->getBaseShapeRef(p_idx)->getInvMass();}
+
+   Mat3 const & getInvInertiaBF(const size_t p_idx) const {return ps_->getBaseShapeRef(p_idx)->getInvInertiaBF();}
+   Mat3 const & getInertiaBF(const size_t p_idx) const {return ps_->getBaseShapeRef(p_idx)->getInertiaBF();}
+   data::BaseShape* getShape(const size_t p_idx) const {return ps_->getBaseShape(p_idx).get();}
+};
+
+
+
+template< typename T>
+std::vector<T> parseStringToVector(std::string inputStr)
+{
+   std::istringstream iss(inputStr);
+   return std::vector<T>{std::istream_iterator<T>(iss),std::istream_iterator<T>()};
+}
+
+real_t radiusFromSphereVolume(real_t volume)
+{
+   return std::cbrt(real_t(3) / ( real_t(4) * math::pi) * volume);
+}
+
+real_t diameterFromSphereVolume(real_t volume)
+{
+   return real_t(2) * radiusFromSphereVolume(volume);
+}
+
+uint_t getIndexOfSecondSemiAxis(Vector3<real_t> semiAxes)
+{
+   std::set<uint_t> indices = {0,1,2};
+   indices.erase(semiAxes.indexOfMin());
+   indices.erase(semiAxes.indexOfMax());
+   return *indices.begin();
+}
+
+void sortVector(Vector3<real_t> & v)
+{
+   std::sort(v.data(),v.data()+3);
+}
+
+real_t sizeFromSemiAxes(Vec3 semiAxes)
+{
+   sortVector(semiAxes);
+   return 2_r * std::sqrt((semiAxes[0] * semiAxes[0] + semiAxes[1] * semiAxes[1]) / 2_r); // factor of 2 because those are SEMI axis
+}
+
+// assuming a mass-equivalent ellipsoid
+Vec3 semiAxesFromInertiaTensor(const Matrix3<real_t> & inertiaTensor, real_t mass)
+{
+   Vec3 semiAxes;
+   semiAxes[0] = std::sqrt( (- inertiaTensor(0,0) + inertiaTensor(1,1) + inertiaTensor(2,2)) / (2_r * mass / 5_r) );
+   semiAxes[1] = std::sqrt( (- inertiaTensor(1,1) + inertiaTensor(2,2) + inertiaTensor(0,0)) / (2_r * mass / 5_r) );
+   semiAxes[2] = std::sqrt( (- inertiaTensor(2,2) + inertiaTensor(0,0) + inertiaTensor(1,1)) / (2_r * mass / 5_r) );
+   return semiAxes;
+}
+
+
+std::vector<real_t> getMeanDiametersFromSieveSizes(std::vector<real_t> sieveSizes)
+{
+   //since grain sizes are logarithmically distributed, it is practice to use the geometric mean
+   std::vector<real_t> meanDiameters(sieveSizes.size()-1,0_r);
+   for(uint_t i = 0; i < meanDiameters.size(); ++i)
+   {
+      meanDiameters[i] = std::sqrt(sieveSizes[i] * sieveSizes[i+1]);
+   }
+   return meanDiameters;
+}
+
+// if totalMass and density are given actual numbers, the resulting particle numbers are a good estimate for the actual numbers
+// else, the resulting numbers are directly proportional to the actual ones, which is sufficient to define the distributions
+std::vector<real_t> transferMassFractionsToParticleNumbersFromAvgVolumes(std::vector<real_t> massFractions, std::vector<real_t> avgVolumePerSizeFraction, real_t totalMass = real_t(1), real_t density = real_t(1) )
+{
+   WALBERLA_CHECK_EQUAL(avgVolumePerSizeFraction.size(), massFractions.size(), "Number of entries in volume and mass-fraction array has to be the same!");
+   std::vector<real_t> particleNumbers(massFractions.size(), real_t(0));
+   for(uint_t n = 0; n < massFractions.size(); ++n )
+   {
+      if(avgVolumePerSizeFraction[n] > 0_r) particleNumbers[n] = totalMass * massFractions[n] / (density * avgVolumePerSizeFraction[n]);
+   }
+   return particleNumbers;
+}
+
+// note: normalVolume is the volume of a typical particle with diameter = 1. For sphere: PI / 6
+std::vector<real_t> transferMassFractionsToParticleNumbers(std::vector<real_t> massFractions, std::vector<real_t> diameters, real_t normalVolume = math::pi / real_t(6), real_t totalMass = real_t(1), real_t density = real_t(1) )
+{
+   WALBERLA_CHECK_EQUAL(diameters.size(), massFractions.size(), "Number of entries in diameter and mass-fraction array has to be the same!");
+   std::vector<real_t> avgVolumePerSizeFraction(massFractions.size(), real_t(0));
+   for(uint_t n = 0; n < massFractions.size(); ++n )
+   {
+      avgVolumePerSizeFraction[n] = normalVolume * diameters[n] * diameters[n] * diameters[n];
+   }
+   return transferMassFractionsToParticleNumbersFromAvgVolumes(massFractions, avgVolumePerSizeFraction, totalMass, density);
+}
+
+real_t computePercentileFromSieveDistribution(std::vector<real_t> diameters, std::vector<real_t> massFractions, real_t percentile)
+{
+   WALBERLA_CHECK(percentile > 0_r && percentile < 100_r, "Percentile is a value between 0 and 100");
+   if(diameters[0] > diameters[1])
+   {
+      // reverse order to have it ascending
+      std::reverse(diameters.begin(), diameters.end());
+      std::reverse(massFractions.begin(), massFractions.end());
+   }
+
+   std::vector<real_t> cdf(massFractions.size(),0_r);
+   std::partial_sum(massFractions.begin(), massFractions.end(), cdf.begin());
+
+   for(uint_t i = 0; i < cdf.size()-1; ++i)
+   {
+      if(cdf[i] <= percentile/100_r && percentile/100_r <= cdf[i+1] )
+      {
+         real_t f_small = cdf[i];
+         real_t f_large = cdf[i+1];
+         if(f_small <= 0.000001_r && f_large>= 0.999999_r)
+         {
+            // special case of uniform distribution -> percentile is this value
+            return diameters[i+1];
+         }
+         real_t phi_small = - std::log2(diameters[i]);
+         real_t phi_large = - std::log2(diameters[i+1]);
+         // logarithmic interpolation of diameter value
+         real_t phi_percentile = phi_small + (phi_large - phi_small) / (f_large - f_small) * (percentile / 100_r - f_small);
+         return std::pow(2_r,-phi_percentile);
+      }
+   }
+   return diameters[0];
+}
+
+
+auto createPlane( std::shared_ptr<data::ParticleStorage> particleStorage,
+                  const Vec3& pos,
+                  const Vec3& normal)
+{
+   auto p = particleStorage->create(true);
+   p->setPosition( pos );
+   p->setBaseShape( std::make_shared<data::HalfSpace>( normal ) );
+   p->getBaseShapeRef()->updateMassAndInertia(real_t(1));
+   p->setOwner( walberla::mpi::MPIManager::instance()->rank() );
+   p->setType( 0 );
+   p->setInteractionRadius(std::numeric_limits<real_t>::infinity());
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::GLOBAL);
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::INFINITE);
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::FIXED);
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::NON_COMMUNICATING);
+   return p;
+}
+
+auto createCylindricalBoundary( std::shared_ptr<data::ParticleStorage> particleStorage,
+                                const Vec3& pos,
+                                const Vec3& axis, real_t radius)
+{
+   auto p = particleStorage->create(true);
+   p->setPosition( pos );
+   p->setBaseShape( std::make_shared<data::CylindricalBoundary>( radius, axis ) );
+   p->getBaseShapeRef()->updateMassAndInertia(real_t(1));
+   p->setOwner( walberla::mpi::MPIManager::instance()->rank() );
+   p->setType( 0 );
+   p->setInteractionRadius(std::numeric_limits<real_t>::infinity());
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::GLOBAL);
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::INFINITE);
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::FIXED);
+   data::particle_flags::set(p->getFlagsRef(), data::particle_flags::NON_COMMUNICATING);
+   return p;
+}
+
+
+void writeParticleInformationToFile(const std::string& filename, const std::string& particleInfoStr, bool logToProcessLocalFiles)
+{
+
+   if(logToProcessLocalFiles)
+   {
+      std::ofstream file;
+      file.open( filename.c_str());
+      file << particleInfoStr;
+      file.close();
+   }else{
+      walberla::mpi::writeMPITextFile( filename, particleInfoStr );
+   }
+