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Diffstat (limited to 'examples/multiComponent/contactAngle3d/contactAngle3d.cpp')
| -rw-r--r-- | examples/multiComponent/contactAngle3d/contactAngle3d.cpp | 393 |
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diff --git a/examples/multiComponent/contactAngle3d/contactAngle3d.cpp b/examples/multiComponent/contactAngle3d/contactAngle3d.cpp new file mode 100644 index 0000000..9f08d4e --- /dev/null +++ b/examples/multiComponent/contactAngle3d/contactAngle3d.cpp @@ -0,0 +1,393 @@ +/* Lattice Boltzmann sample, written in C++, using the OpenLB + * library + * + * Copyright (C) 2008 Orestis Malaspinas, Andrea Parmigiani + * 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. + */ + +/* contactAngle3d.cpp + * In this example a semi-spherical droplet of fluid is initialised + * within a different fluid at a solid boundary. The contact angle + * is measured as the droplet comes to equilibrium. This is compared + * with the analytical angle (100 degrees) predicted by the + * parameters set for the boundary. + * + * This example demonstrates how to use the wetting solid boundaries + * for the free-energy model with two fluid components. + */ + +#include "olb3D.h" +#include "olb3D.hh" // use only generic version! +#include <cstdlib> +#include <iostream> +#include <fstream> +#include <math.h> + +using namespace olb; +using namespace olb::descriptors; +using namespace olb::graphics; +using namespace std; + +typedef double T; +#define DESCRIPTOR D3Q19<CHEM_POTENTIAL,FORCE> + +// Parameters for the simulation setup +const int N = 75; +const T nxy = 75.; +const T nz = 50.; +const T radius = 0.25 * nxy; + +const T alpha = 1.; // Interfacial width [lattice units] +const T kappa1 = 0.005; // For surface tensions [lattice units] +const T kappa2 = 0.005; // For surface tensions [lattice units] +const T gama = 10.; // For mobility of interface [lattice units] +const T h1 = 0.0001448; // Contact angle 80 degrees [lattice units] +const T h2 = -0.0001448; // Contact angle 100 degrees [lattice units] + +const int maxIter = 70000; +const int vtkIter = 200; +const int statIter = 200; +const bool calcAngle = true; + +T angle_prev = 90.; + + +void prepareGeometry( SuperGeometry3D<T>& superGeometry, + UnitConverter<T, DESCRIPTOR>& converter) { + + OstreamManager clout( std::cout,"prepareGeometry" ); + clout << "Prepare Geometry ..." << std::endl; + + superGeometry.rename( 0,2 ); + + Vector<T,3> extend(nxy+2., nxy+2., nz-1.*converter.getPhysDeltaX() ); + Vector<T,3> origin( -1., -1., 0.5*converter.getPhysDeltaX() ); + IndicatorCuboid3D<T> inner ( extend, origin ); + superGeometry.rename( 2,1,inner ); + + superGeometry.innerClean(); + superGeometry.checkForErrors(); + superGeometry.print(); + + clout << "Prepare Geometry ... OK" << std::endl; +} + + +void prepareLattice( SuperLattice3D<T, DESCRIPTOR>& sLattice1, + SuperLattice3D<T, DESCRIPTOR>& sLattice2, + Dynamics<T, DESCRIPTOR>& bulkDynamics1, + Dynamics<T, DESCRIPTOR>& bulkDynamics2, + UnitConverter<T, DESCRIPTOR>& converter, + SuperGeometry3D<T>& superGeometry, + sOnLatticeBoundaryCondition3D<T,DESCRIPTOR>& sOnBC1, + sOnLatticeBoundaryCondition3D<T,DESCRIPTOR>& sOnBC2 ) { + + OstreamManager clout( std::cout,"prepareLattice" ); + clout << "Prepare Lattice ..." << std::endl; + + // Define lattice Dynamics + sLattice1.defineDynamics( superGeometry, 0, &instances::getNoDynamics<T, DESCRIPTOR>() ); + sLattice2.defineDynamics( superGeometry, 0, &instances::getNoDynamics<T, DESCRIPTOR>() ); + sLattice1.defineDynamics( superGeometry, 1, &bulkDynamics1 ); + sLattice2.defineDynamics( superGeometry, 1, &bulkDynamics2 ); + sLattice1.defineDynamics( superGeometry, 2, &instances::getNoDynamics<T, DESCRIPTOR>() ); + sLattice2.defineDynamics( superGeometry, 2, &instances::getNoDynamics<T, DESCRIPTOR>() ); + + // Add wall boundary + sOnBC1.addFreeEnergyWallBoundary( superGeometry, 2, alpha, kappa1, kappa2, h1, h2, 1 ); + sOnBC2.addFreeEnergyWallBoundary( superGeometry, 2, alpha, kappa1, kappa2, h1, h2, 2 ); + + // Bulk initial conditions + // Define spherical domain for fluid 2 + std::vector<T> v( 3,T() ); + AnalyticalConst3D<T,T> zeroVelocity( v ); + + AnalyticalConst3D<T,T> one( 1.0 ); + SmoothIndicatorSphere3D<T,T> sphere( {nxy/2., nxy/2., 0.}, radius, 10.*alpha ); + + AnalyticalIdentity3D<T,T> rho( one ); + AnalyticalIdentity3D<T,T> phi( one - sphere - sphere ); + + sLattice1.iniEquilibrium( superGeometry, 1, rho, zeroVelocity ); + sLattice2.iniEquilibrium( superGeometry, 1, phi, zeroVelocity ); + + sLattice1.iniEquilibrium( superGeometry, 2, rho, zeroVelocity ); + sLattice2.iniEquilibrium( superGeometry, 2, phi, zeroVelocity ); + + sLattice1.initialize(); + sLattice2.initialize(); + + sLattice1.communicate(); + sLattice2.communicate(); + + clout << "Prepare Lattice ... OK" << std::endl; +} + + +void prepareCoupling( SuperLattice3D<T, DESCRIPTOR>& sLattice1, + SuperLattice3D<T, DESCRIPTOR>& sLattice2, + SuperGeometry3D<T>& superGeometry ) { + + OstreamManager clout( std::cout,"prepareCoupling" ); + clout << "Add lattice coupling" << endl; + + // Add the lattice couplings (not to the solid nodes) + // The chemical potential coupling must come before the force coupling + FreeEnergyChemicalPotentialGenerator3D<T, DESCRIPTOR> coupling1( + alpha, kappa1, kappa2); + FreeEnergyForceGenerator3D<T, DESCRIPTOR> coupling2; + + // Suppress compiler warnings + coupling1.shift(0, 0, 0); + coupling2.shift(0, 0, 0); + + sLattice1.addLatticeCoupling( superGeometry, 1, coupling1, sLattice2 ); + sLattice2.addLatticeCoupling( superGeometry, 1, coupling2, sLattice1 ); + + clout << "Add lattice coupling ... OK!" << endl; +} + + +void getResults( SuperLattice3D<T, DESCRIPTOR>& sLattice1, + SuperLattice3D<T, DESCRIPTOR>& sLattice2, int iT, + SuperGeometry3D<T>& superGeometry, Timer<T>& timer, + UnitConverter<T, DESCRIPTOR> converter ) { + + OstreamManager clout( std::cout,"getResults" ); + SuperVTMwriter3D<T> vtmWriter( "contactAngle3d" ); + + if ( iT==0 ) { + // Writes the geometry, cuboid no. and rank no. as vti file for visualization + SuperLatticeGeometry3D<T, DESCRIPTOR> geometry( sLattice1, superGeometry ); + SuperLatticeCuboid3D<T, DESCRIPTOR> cuboid( sLattice1 ); + SuperLatticeRank3D<T, DESCRIPTOR> rank( sLattice1 ); + vtmWriter.write( geometry ); + vtmWriter.write( cuboid ); + vtmWriter.write( rank ); + vtmWriter.createMasterFile(); + } + + // Get statistics + if ( iT%statIter==0 ) { + // Timer console output + timer.update( iT ); + timer.printStep(); + sLattice1.getStatistics().print( iT, converter.getPhysTime(iT) ); + sLattice2.getStatistics().print( iT, converter.getPhysTime(iT) ); + } + + // Writes the VTK files + if ( iT%vtkIter==0 ) { + AnalyticalConst3D<T,T> half_( 0.5 ); + SuperLatticeFfromAnalyticalF3D<T, DESCRIPTOR> half(half_, sLattice1); + + SuperLatticeVelocity3D<T, DESCRIPTOR> velocity( sLattice1 ); + SuperLatticeDensity3D<T, DESCRIPTOR> rho( sLattice1 ); + rho.getName() = "rho"; + SuperLatticeDensity3D<T, DESCRIPTOR> phi( sLattice2 ); + phi.getName() = "phi"; + + SuperIdentity3D<T,T> c1 (half*(rho+phi)); + c1.getName() = "density-fluid-1"; + SuperIdentity3D<T,T> c2 (half*(rho-phi)); + c2.getName() = "density-fluid-2"; + + vtmWriter.addFunctor( velocity ); + vtmWriter.addFunctor( rho ); + vtmWriter.addFunctor( phi ); + vtmWriter.addFunctor( c1 ); + vtmWriter.addFunctor( c2 ); + vtmWriter.write( iT ); + + // Evaluation of contact angle + if (calcAngle) { + int Nz = (int)( N * nz / nxy ); + T dx = converter.getPhysDeltaX(); + AnalyticalFfromSuperF3D<T,T> interpolPhi( phi, true, 1 ); + + T base1 = 0.; + T base2 = 0.; + T height1 = 0.; + T height2 = 0.; + + double pos[3] = {0., nxy/2., dx}; + for(int ix=0; ix<N; ix++) { + T phi1, phi2; + pos[0] = ix * dx; + interpolPhi( &phi1, pos ); + if (phi1 < 0.) { + pos[0] = (ix-1) * dx; + interpolPhi( &phi2, pos ); + base1 = 2. * ( 0.5*N - ix + phi1/(phi1-phi2) ); + break; + } + } + + pos[2] = 3.*dx; + for(int ix=0; ix<N; ix++) { + T phi1, phi2; + pos[0] = ix * dx; + interpolPhi( &phi1, pos ); + if (phi1 < 0.) { + pos[0] = (ix-1) * dx; + interpolPhi( &phi2, pos ); + base2 = 2. * ( 0.5*N - ix + phi1/(phi1-phi2) ); + break; + } + } + + pos[0] = nxy / 2.; + for(int iz=2; iz<Nz; iz++) { + T phi1, phi2; + pos[2] = iz * dx; + interpolPhi( &phi1, pos ); + if (phi1 > 0.) { + pos[2] = (iz-1) * dx; + interpolPhi( &phi2, pos ); + height1 = iz - 1. - phi1/(phi1-phi2); + height2 = iz - 3. - phi1/(phi1-phi2); + break; + } + } + + // Calculate simulated contact angle + T pi = 3.14159265; + T height = height1 + 1.; + T base = base1 + 2 * (radius - height1) / base1; + T radius = (4.*height2*height2 + base2*base2) / ( 8.*height2 ); + T angle_rad = pi + atan( 0.5*base / (radius - height) ); + T angle = angle_rad * 180. / pi; + if ( angle > 180. ) angle -= 180.; + + // Calculate theoretical contact angle + T ak1 = alpha * kappa1; + T ak2 = alpha * kappa2; + T k12 = kappa1 + kappa2; + T num1 = pow(ak1 + 4 * h1, 1.5) - pow(ak1 - 4 * h1, 1.5); + T num2 = pow(ak2 + 4 * h2, 1.5) - pow(ak2 - 4 * h2, 1.5); + T angle_an = 180 / pi * acos(num2 / (2 * k12 * sqrt(ak2)) - \ + num1 / (2 * k12 * sqrt(ak1))); + + clout << "----->>>>> Contact angle: " << angle << " ; "; + clout << "Analytical contact angle: " << angle_an << std::endl; + clout << "----->>>>> Difference to previous: " << angle-angle_prev << std::endl; + angle_prev = angle; + } + } +} + + +int main( int argc, char *argv[] ) { + + // === 1st Step: Initialization === + + olbInit( &argc, &argv ); + singleton::directories().setOutputDir( "./tmp/" ); + OstreamManager clout( std::cout,"main" ); + + UnitConverterFromResolutionAndRelaxationTime<T,DESCRIPTOR> converter( + (T) N, // resolution + (T) 1., // lattice relaxation time (tau) + (T) nxy, // charPhysLength: reference length of simulation geometry + (T) 0.0001, // charPhysVelocity: maximal/highest expected velocity during simulation in __m / s__ + (T) 1.002e-8, // physViscosity: physical kinematic viscosity in __m^2 / s__ + (T) 1. // physDensity: physical density in __kg / m^3__ + ); + + // Prints the converter log as console output + converter.print(); + + // === 2nd Step: Prepare Geometry === + std::vector<T> extend = { nxy, nxy, nz }; + std::vector<T> origin = { 0., 0., 0. }; + IndicatorCuboid3D<T> cuboid(extend,origin); +#ifdef PARALLEL_MODE_MPI + CuboidGeometry3D<T> cGeometry( cuboid, converter.getPhysDeltaX(), singleton::mpi().getSize() ); +#else + CuboidGeometry3D<T> cGeometry( cuboid, converter.getPhysDeltaX() ); +#endif + + // Set periodic boundaries to the domain + cGeometry.setPeriodicity( true, true, false ); + + // Instantiation of loadbalancer + HeuristicLoadBalancer<T> loadBalancer( cGeometry ); + loadBalancer.print(); + + // Instantiation of superGeometry + SuperGeometry3D<T> superGeometry( cGeometry,loadBalancer ); + + prepareGeometry( superGeometry, converter ); + + // === 3rd Step: Prepare Lattice === + SuperLattice3D<T, DESCRIPTOR> sLattice1( superGeometry ); + SuperLattice3D<T, DESCRIPTOR> sLattice2( superGeometry ); + + ForcedBGKdynamics<T, DESCRIPTOR> bulkDynamics1 ( + converter.getLatticeRelaxationFrequency(), + instances::getBulkMomenta<T,DESCRIPTOR>() ); + + FreeEnergyBGKdynamics<T, DESCRIPTOR> bulkDynamics2 ( + converter.getLatticeRelaxationFrequency(), gama, + instances::getBulkMomenta<T,DESCRIPTOR>() ); + + sOnLatticeBoundaryCondition3D<T,DESCRIPTOR> sOnBC1( sLattice1 ); + sOnLatticeBoundaryCondition3D<T,DESCRIPTOR> sOnBC2( sLattice2 ); + createLocalBoundaryCondition3D<T,DESCRIPTOR> (sOnBC1); + createLocalBoundaryCondition3D<T,DESCRIPTOR> (sOnBC2); + + prepareLattice( sLattice1, sLattice2, bulkDynamics1, bulkDynamics2, + converter, superGeometry, sOnBC1, sOnBC2 ); + + prepareCoupling( sLattice1, sLattice2, superGeometry); + + SuperExternal3D<T, DESCRIPTOR,CHEM_POTENTIAL> sExternal1 (superGeometry, sLattice1, sLattice1.getOverlap() ); + SuperExternal3D<T, DESCRIPTOR,CHEM_POTENTIAL> sExternal2 (superGeometry, sLattice2, sLattice2.getOverlap() ); + + // === 4th Step: Main Loop with Timer === + int iT = 0; + clout << "starting simulation..." << endl; + Timer<T> timer( maxIter, superGeometry.getStatistics().getNvoxel() ); + timer.start(); + + for ( iT=0; iT<=maxIter; ++iT ) { + // Computation and output of the results + getResults( sLattice1, sLattice2, iT, superGeometry, timer, converter ); + + // Collide and stream execution + sLattice1.collideAndStream(); + sLattice2.collideAndStream(); + + // MPI communication for lattice data + sLattice1.communicate(); + sLattice2.communicate(); + + // Execute coupling between the two lattices + sLattice1.executeCoupling(); + sExternal1.communicate(); + sExternal2.communicate(); + sLattice2.executeCoupling(); + } + + timer.stop(); + timer.printSummary(); + +} + |