From f96bc0b416b87261a5be6b6c4e5cbf860c084a55 Mon Sep 17 00:00:00 2001 From: Michael Kuron <mkuron@icp.uni-stuttgart.de> Date: Sat, 8 Jul 2017 18:53:33 +0200 Subject: [PATCH] Squirmer test case --- src/pe/rigidbody/Squirmer.cpp | 6 +- .../boundary/SimpleBB.h | 20 +- tests/pe_coupling/CMakeLists.txt | 3 + .../momentum_exchange_method/SquirmerTest.cpp | 474 ++++++++++++++++++ 4 files changed, 495 insertions(+), 8 deletions(-) create mode 100644 tests/pe_coupling/momentum_exchange_method/SquirmerTest.cpp diff --git a/src/pe/rigidbody/Squirmer.cpp b/src/pe/rigidbody/Squirmer.cpp index 9bd809802..99f650b00 100644 --- a/src/pe/rigidbody/Squirmer.cpp +++ b/src/pe/rigidbody/Squirmer.cpp @@ -106,7 +106,7 @@ const Vec3 Squirmer::velFromBF( real_t px, real_t py, real_t pz ) const */ const Vec3 Squirmer::velFromBF( const Vec3& rpos ) const { - return Sphere::velFromBF( rpos ) + getSquirmerVelocity( rpos ); + return Sphere::velFromBF( rpos ) + getSquirmerVelocity( R_ * rpos ); } //************************************************************************************************* @@ -130,6 +130,7 @@ const Vec3 Squirmer::velFromWF( real_t px, real_t py, real_t pz ) const //************************************************************************************************* /*!\brief Returns the squirmer's surface velocity at a given relative position. * + * \param rpos The relative global coordinate. * \return The local surface velocity of the squirmer. */ const Vec3 Squirmer::getSquirmerVelocity( const Vec3& rpos ) const @@ -153,8 +154,7 @@ const Vec3 Squirmer::getSquirmerVelocity( const Vec3& rpos ) const */ const Vec3 Squirmer::velFromWF( const Vec3& gpos ) const { - const auto rpos = pointFromWFtoBF( gpos ); - return Sphere::velFromWF( gpos ) + getSquirmerVelocity( rpos ); + return Sphere::velFromWF( gpos ) + getSquirmerVelocity( gpos - gpos_ ); } //************************************************************************************************* diff --git a/src/pe_coupling/momentum_exchange_method/boundary/SimpleBB.h b/src/pe_coupling/momentum_exchange_method/boundary/SimpleBB.h index a6807a6ff..161dfc872 100644 --- a/src/pe_coupling/momentum_exchange_method/boundary/SimpleBB.h +++ b/src/pe_coupling/momentum_exchange_method/boundary/SimpleBB.h @@ -59,8 +59,6 @@ namespace pe_coupling { template< typename LatticeModel_T, typename FlagField_T > class SimpleBB : public Boundary< typename FlagField_T::flag_t > { - static_assert( LatticeModel_T::compressible == false, "Only works with incompressible models!" ); - typedef lbm::PdfField< LatticeModel_T > PDFField_T; typedef typename LatticeModel_T::Stencil Stencil_T; typedef typename FlagField_T::flag_t flag_t; @@ -172,9 +170,21 @@ inline void SimpleBB< LatticeModel_T, FlagField_T >::treatDirection( const cell_ auto boundaryVelocity = body.velFromWF( boundaryPosition ); // include effect of boundary velocity - pdf_new -= real_c(3.0) * alpha * LatticeModel_T::w[ Stencil_T::idx[dir] ] * ( real_c( stencil::cx[ dir ] ) * boundaryVelocity[0] + - real_c( stencil::cy[ dir ] ) * boundaryVelocity[1] + - real_c( stencil::cz[ dir ] ) * boundaryVelocity[2] ); + if( LatticeModel_T::compressible ) + { + const auto density = pdfField_->getDensity(x,y,z); + pdf_new -= real_c(3.0) * alpha * density * LatticeModel_T::w[ Stencil_T::idx[dir] ] * + ( real_c( stencil::cx[ dir ] ) * boundaryVelocity[0] + + real_c( stencil::cy[ dir ] ) * boundaryVelocity[1] + + real_c( stencil::cz[ dir ] ) * boundaryVelocity[2] ); + } + else + { + pdf_new -= real_c(3.0) * alpha * LatticeModel_T::w[ Stencil_T::idx[dir] ] * + ( real_c( stencil::cx[ dir ] ) * boundaryVelocity[0] + + real_c( stencil::cy[ dir ] ) * boundaryVelocity[1] + + real_c( stencil::cz[ dir ] ) * boundaryVelocity[2] ); + } // carry out the boundary handling pdfField_->get( nx, ny, nz, Stencil_T::invDirIdx(dir) ) = pdf_new; diff --git a/tests/pe_coupling/CMakeLists.txt b/tests/pe_coupling/CMakeLists.txt index 24b8d2a53..e31ded9e8 100644 --- a/tests/pe_coupling/CMakeLists.txt +++ b/tests/pe_coupling/CMakeLists.txt @@ -123,3 +123,6 @@ waLBerla_execute_test( NAME TorqueSphereMEMMRFuncTest COMMAND $<TARGET_FILE waLBerla_execute_test( NAME TorqueSphereMEMMRSingleTest COMMAND $<TARGET_FILE:TorqueSphereMEM> --MO_MR PROCESSES 1 LABELS longrun CONFIGURATIONS Release RelWithDbgInfo ) waLBerla_execute_test( NAME TorqueSphereMEMMRParallelTest COMMAND $<TARGET_FILE:TorqueSphereMEM> --MO_MR PROCESSES 8 LABELS verylongrun CONFIGURATIONS Release RelWithDbgInfo ) +waLBerla_compile_test( FILES momentum_exchange_method/SquirmerTest.cpp DEPENDS blockforest pe timeloop ) +waLBerla_execute_test( NAME SquirmerShortTest COMMAND $<TARGET_FILE:SquirmerTest> --shortrun PROCESSES 1 ) +waLBerla_execute_test( NAME SquirmerTest COMMAND $<TARGET_FILE:SquirmerTest> PROCESSES 1 CONFIGURATIONS Release RelWithDbgInfo ) diff --git a/tests/pe_coupling/momentum_exchange_method/SquirmerTest.cpp b/tests/pe_coupling/momentum_exchange_method/SquirmerTest.cpp new file mode 100644 index 000000000..235fcc2a6 --- /dev/null +++ b/tests/pe_coupling/momentum_exchange_method/SquirmerTest.cpp @@ -0,0 +1,474 @@ +//====================================================================================================================== +// +// 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 SquirmerTest.cpp +//! \ingroup pe_coupling +//! \author Christian Burkard <buch@icp.uni-stuttgart.de> +//! \author Michael Kuron <mkuron@icp.uni-stuttgart.de> +// +//====================================================================================================================== + +#include "blockforest/Initialization.h" +#include "blockforest/communication/UniformBufferedScheme.h" + +#include "boundary/all.h" + +#include "core/DataTypes.h" +#include "core/Environment.h" +#include "core/debug/Debug.h" +#include "core/debug/TestSubsystem.h" +#include "core/logging/Logging.h" +#include "core/math/all.h" +#include "core/SharedFunctor.h" +#include "core/timing/RemainingTimeLogger.h" +#include "core/mpi/MPIManager.h" + +#include "domain_decomposition/SharedSweep.h" + +#include "field/AddToStorage.h" +#include "field/communication/PackInfo.h" + +#include "lbm/boundary/all.h" +#include "lbm/communication/PdfFieldPackInfo.h" +#include "lbm/field/AddToStorage.h" +#include "lbm/field/PdfField.h" +#include "lbm/lattice_model/D3Q19.h" +#include "lbm/lattice_model/ForceModel.h" +#include "lbm/sweeps/CellwiseSweep.h" +#include "lbm/sweeps/SweepWrappers.h" + +#include "stencil/D3Q7.h" + +#include "timeloop/SweepTimeloop.h" + +#include "pe/rigidbody/SquirmerFactory.h" +#include "pe/communication/rigidbody/Squirmer.h" +#include "pe/basic.h" + +#include "pe_coupling/mapping/all.h" +#include "pe_coupling/momentum_exchange_method/all.h" +#include "pe_coupling/utility/all.h" + +#include "field/vtk/FlagFieldCellFilter.h" +#include "field/vtk/VTKWriter.h" +#include "lbm/vtk/Velocity.h" +#include "vtk/VTKOutput.h" + +/////////// +// USING // +/////////// + +using namespace walberla; +using walberla::uint_t; + +// PDF field, flag field & body field +typedef lbm::force_model::None ForceModel_T; +typedef lbm::D3Q19< lbm::collision_model::TRT, false, ForceModel_T > LatticeModel_T; + +typedef LatticeModel_T::Stencil Stencil_T; +typedef lbm::PdfField< LatticeModel_T > PdfField_T; + +typedef walberla::uint8_t flag_t; +typedef FlagField< flag_t > FlagField_T; +typedef GhostLayerField< pe::BodyID, 1 > PeBodyField_T; + +const uint_t FieldGhostLayers = 1; + +// boundary handling +typedef pe_coupling::SimpleBB < LatticeModel_T, FlagField_T > MO_BB_T; + +typedef boost::tuples::tuple< MO_BB_T > BoundaryConditions_T; +typedef BoundaryHandling< FlagField_T, Stencil_T, BoundaryConditions_T > BoundaryHandling_T; + +typedef boost::tuple<pe::Squirmer> BodyTypeTuple ; + +/////////// +// FLAGS // +/////////// + +const FlagUID Fluid_Flag ( "fluid" ); +const FlagUID MO_BB_Flag ( "moving obstacle BB" ); +const FlagUID FormerMO_BB_Flag ( "former moving obstacle BB" ); + +///////////////////////////////////// +// BOUNDARY HANDLING CUSTOMIZATION // +///////////////////////////////////// + +class MyBoundaryHandling +{ +public: + + MyBoundaryHandling( const BlockDataID & flagFieldID, const BlockDataID & pdfFieldID, const BlockDataID & bodyFieldID ) : + flagFieldID_( flagFieldID ), pdfFieldID_( pdfFieldID ), bodyFieldID_ ( bodyFieldID ) {} + + BoundaryHandling_T * operator()( IBlock* const block, const StructuredBlockStorage* const storage ) const; + +private: + + const BlockDataID flagFieldID_; + const BlockDataID pdfFieldID_; + const BlockDataID bodyFieldID_; + +}; // class MyBoundaryHandling + +//////////////////////////////// +// VTK OUTPUT HELPER FUNCTION // +//////////////////////////////// + +BoundaryHandling_T * MyBoundaryHandling::operator()( IBlock * const block, const StructuredBlockStorage * const storage ) const +{ + WALBERLA_ASSERT_NOT_NULLPTR( block ); + WALBERLA_ASSERT_NOT_NULLPTR( storage ); + + FlagField_T * flagField = block->getData< FlagField_T >( flagFieldID_ ); + PdfField_T * pdfField = block->getData< PdfField_T > ( pdfFieldID_ ); + PeBodyField_T * bodyField = block->getData< PeBodyField_T >( bodyFieldID_ ); + + const auto fluid = flagField->flagExists( Fluid_Flag ) ? flagField->getFlag( Fluid_Flag ) : flagField->registerFlag( Fluid_Flag ); + + BoundaryHandling_T * handling = new BoundaryHandling_T( "fixed obstacle boundary handling", flagField, fluid, + boost::tuples::make_tuple( MO_BB_T ( "MO_BB", MO_BB_Flag, pdfField, flagField, bodyField, fluid, *storage, *block ) ) ); + + handling->fillWithDomain( FieldGhostLayers ); + + return handling; +} + +shared_ptr< vtk::VTKOutput> createFluidFieldVTKWriter( shared_ptr< StructuredBlockForest > & blocks, + const BlockDataID & pdfFieldId, const BlockDataID & flagFieldId, + std::string fname ) +{ + auto pdfFieldVTKWriter = vtk::createVTKOutput_BlockData( blocks, fname, uint_c(1), uint_c(0) ); + + field::FlagFieldCellFilter< FlagField_T > fluidFilter( flagFieldId ); + fluidFilter.addFlag( Fluid_Flag ); + pdfFieldVTKWriter->addCellInclusionFilter( fluidFilter ); + + auto velocityWriter = make_shared< lbm::VelocityVTKWriter< LatticeModel_T, float > >( pdfFieldId, "VelocityFromPDF" ); + pdfFieldVTKWriter->addCellDataWriter( velocityWriter ); + + return pdfFieldVTKWriter; +} + +class ResetPosition +{ +public: + + explicit ResetPosition( const shared_ptr<StructuredBlockStorage> & blockStorage, + const BlockDataID & bodyStorageID, + real_t dt ) + : blockStorage_( blockStorage ) + , bodyStorageID_( bodyStorageID ) + , dt_( dt ) + {} + + void operator()() + { + for (auto blockIt = blockStorage_->begin(); blockIt != blockStorage_->end(); ++blockIt) + { + for( auto bodyIt = pe::BodyIterator::begin(*blockIt, bodyStorageID_); bodyIt != pe::BodyIterator::end(); ++bodyIt ) + { + bodyIt->setPosition( bodyIt->getPosition() - bodyIt->getLinearVel() * dt_ ); + } + } + } + +private: + + shared_ptr<StructuredBlockStorage> blockStorage_; + const BlockDataID & bodyStorageID_; + + real_t dt_; + +}; // class ResetPosition + + +Vector3<real_t> analytical_velocity(Vector3<real_t> r, real_t b1, real_t b2, Vector3<real_t> e, real_t radius) +{ + auto r_len = r.length(); + auto rs = r.getNormalized(); + auto frac = radius/r_len; + auto frac2 = frac*frac; + auto frac3 = frac2*frac; + auto frac4 = frac3*frac; + + return b1 * frac3 * ((e*rs) * rs - e / real_c(3.0)) + ( frac4 - frac2 ) * b2 * 0.5 * ( 3 * (e * rs) * (e * rs) - 1 ) * rs + frac4 * b2 * (e*rs) * ( (e*rs) * rs - e); +} + + +int main( int argc, char **argv ) +{ + debug::enterTestMode(); + + mpi::Environment env( argc, argv ); + + auto processes = MPIManager::instance()->numProcesses(); + + if( processes != 1 && processes != 2 && processes != 4 && processes != 8) + { + std::cerr << "Number of processes must be equal to either 1, 2, 4, or 8!" << std::endl; + return EXIT_FAILURE; + } + + bool shortrun = false; + bool writevtk = false; + for( int i = 1; i < argc; ++i ) + { + if( std::strcmp( argv[i], "--shortrun" ) == 0 ) { shortrun = true; continue; } + if( std::strcmp( argv[i], "--vtk" ) == 0 ) { writevtk = true; continue; } + } + + /////////////////////////// + // SIMULATION PROPERTIES // + /////////////////////////// + + real_t R = 3; + uint_t L = 24; + uint_t T = 1000; + if (shortrun) + { + L = 10; + T = 10; + } + const real_t dx = real_c(1.0); + const real_t dt = real_c(1.0); + const real_t omega = lbm::collision_model::omegaFromViscosity( real_c(1.0/6.0) ); + const real_t v0 = real_c(0.01); + const real_t beta = real_c(5.0); + + /////////////////////////// + // BLOCK STRUCTURE SETUP // + /////////////////////////// + const uint_t XBlocks = (processes >= 2) ? uint_t( 2 ) : uint_t( 1 ); + const uint_t YBlocks = (processes >= 4) ? uint_t( 2 ) : uint_t( 1 ); + const uint_t ZBlocks = (processes == 8) ? uint_t( 2 ) : uint_t( 1 ); + const uint_t XCells = L / XBlocks; + const uint_t YCells = L / YBlocks; + const uint_t ZCells = L / ZBlocks; + + // create fully periodic domain + auto blocks = blockforest::createUniformBlockGrid( XBlocks, YBlocks, ZBlocks, XCells, YCells, ZCells, dx, true, + true, true, true ); + + //////// + // PE // + //////// + + auto globalBodyStorage = make_shared<pe::BodyStorage>(); + pe::SetBodyTypeIDs<BodyTypeTuple>::execute(); + auto bodyStorageID = blocks->addBlockData(pe::createStorageDataHandling<BodyTypeTuple>(), "pe Body Storage"); + auto ccdID = blocks->addBlockData(pe::ccd::createHashGridsDataHandling( globalBodyStorage, bodyStorageID ), "CCD"); + auto fcdID = blocks->addBlockData(pe::fcd::createSimpleFCDDataHandling<BodyTypeTuple>(), "FCD"); + + pe::cr::HCSITS cr(globalBodyStorage, blocks->getBlockStoragePointer(), bodyStorageID, ccdID, fcdID); + + ///////////////// + // PE COUPLING // + ///////////////// + + // connect to pe + const real_t overlap = real_c( 1.5 ) * dx; + + if( R > real_c( L ) * real_c(0.5) - overlap ) + { + std::cerr << "Periodic sphere is too large and would lead to invalid PE state!" << std::endl; + return EXIT_FAILURE; + } + + boost::function<void(void)> syncCall = boost::bind( pe::syncShadowOwners<BodyTypeTuple>, boost::ref(blocks->getBlockForest()), bodyStorageID, static_cast<WcTimingTree*>(NULL), overlap, false ); + + const auto myMat = pe::createMaterial( "myMat", real_c(1), real_t(0), real_t(1), real_t(1), real_t(0), real_t(1), real_t(1), real_t(0), real_t(0) ); + + // create the squirmer in the middle of the domain + const Vector3<real_t> position (real_c(L)*real_c(0.5), real_c(L)*real_c(0.5), real_c(L)*real_c(0.5)); + const Vector3<real_t> up(0.0, 0.0, 1.0); + const Vector3<real_t> orientation(1.0, 0.0, 0.0); + const auto w = std::acos(up*orientation); + math::Quaternion<real_t> q(up % orientation, w); + auto squirmer = pe::createSquirmer(*globalBodyStorage, blocks->getBlockStorage(), bodyStorageID, 0, position, R, v0, beta, myMat); + if (squirmer) + squirmer->setOrientation(q); + + syncCall(); + + /////////////////////// + // ADD DATA TO BLOCKS // + //////////////////////// + + // create the lattice model + LatticeModel_T latticeModel = LatticeModel_T( lbm::collision_model::TRT::constructWithMagicNumber( omega ) ); + + // add PDF field ( uInit = <0,0,0>, rhoInit = 1 ) + BlockDataID pdfFieldID = lbm::addPdfFieldToStorage< LatticeModel_T >( blocks, "pdf field (zyxf)", latticeModel, FieldGhostLayers ); + + // add flag field + BlockDataID flagFieldID = field::addFlagFieldToStorage< FlagField_T >( blocks, "flag field" ); + + // add body field + BlockDataID bodyFieldID = field::addToStorage< PeBodyField_T >( blocks, "body field", NULL, field::zyxf ); + + // add boundary handling & initialize outer domain boundaries + BlockDataID boundaryHandlingID = blocks->addStructuredBlockData< BoundaryHandling_T >( + MyBoundaryHandling( flagFieldID, pdfFieldID, bodyFieldID ), "boundary handling" ); + + /////////////// + // TIME LOOP // + /////////////// + + // create the timeloop + SweepTimeloop timeloop( blocks->getBlockStorage(), T ); + + // sweep for updating the pe body mapping into the LBM simulation + timeloop.add() + << Sweep( pe_coupling::BodyMapping< BoundaryHandling_T >( blocks, boundaryHandlingID, bodyStorageID, bodyFieldID, MO_BB_Flag, FormerMO_BB_Flag ), + "Body Mapping" ); + + // sweep for restoring PDFs in cells previously occupied by pe bodies + typedef pe_coupling::EquilibriumReconstructor< LatticeModel_T, BoundaryHandling_T > Reconstructor_T; + Reconstructor_T reconstructor( blocks, boundaryHandlingID, pdfFieldID, bodyFieldID ); + timeloop.add() + << Sweep( pe_coupling::PDFReconstruction< LatticeModel_T, BoundaryHandling_T, Reconstructor_T >( blocks, boundaryHandlingID, bodyStorageID, bodyFieldID, + reconstructor, FormerMO_BB_Flag, Fluid_Flag ), "PDF Restore" ); + + // setup of the LBM communication for synchronizing the pdf field between neighboring blocks + boost::function< void () > commFunction; + + blockforest::communication::UniformBufferedScheme< stencil::D3Q27 > scheme( blocks ); + scheme.addPackInfo( make_shared< field::communication::PackInfo< PdfField_T > >( pdfFieldID ) ); + commFunction = scheme; + + // uses standard bounce back boundary conditions + pe_coupling::mapMovingBodies< BoundaryHandling_T >( blocks, boundaryHandlingID, bodyStorageID, bodyFieldID, MO_BB_Flag ); + + auto sweep = lbm::makeCellwiseSweep< LatticeModel_T, FlagField_T >( pdfFieldID, flagFieldID, Fluid_Flag ); + + // collision sweep + timeloop.add() << Sweep( lbm::makeCollideSweep( sweep ), "cell-wise LB sweep (collide)" ); + + // add LBM communication function and boundary handling sweep (does the hydro force calculations and the no-slip treatment) + timeloop.add() << BeforeFunction( commFunction, "LBM Communication" ) + << Sweep( BoundaryHandling_T::getBlockSweep( boundaryHandlingID ), "Boundary Handling" ); + + // streaming + timeloop.add() << Sweep( lbm::makeStreamSweep( sweep ), "cell-wise LB sweep (stream)" ); + + // add pe timesteps + timeloop.addFuncAfterTimeStep( pe_coupling::TimeStep( blocks, bodyStorageID, cr, syncCall, dt ), "pe Time Step" ); + timeloop.addFuncAfterTimeStep( ResetPosition( blocks, bodyStorageID, dt ), "Reset pe positions" ); + + timeloop.addFuncAfterTimeStep( RemainingTimeLogger( timeloop.getNrOfTimeSteps() ), "Remaining Time Logger" ); + + //////////////////////// + // EXECUTE SIMULATION // + //////////////////////// + + WALBERLA_LOG_INFO_ON_ROOT("Starting test..."); + WcTimingPool timeloopTiming; + timeloop.run( timeloopTiming ); + timeloopTiming.logResultOnRoot(); + + if (writevtk) + { + WALBERLA_LOG_INFO_ON_ROOT("Writing out VTK file..."); + auto pdfFieldVTKWriter = createFluidFieldVTKWriter( blocks, pdfFieldID, flagFieldID, "fluid_field" ); + auto wf = vtk::writeFiles( pdfFieldVTKWriter ); + wf(); + auto flagFieldVTK = vtk::createVTKOutput_BlockData( blocks, "flag_field", 1, 0 ); + flagFieldVTK->addCellDataWriter( make_shared< field::VTKWriter< FlagField_T > >( flagFieldID, "FlagField" ) ); + vtk::writeFiles( flagFieldVTK )(); + } + + if (squirmer) // this object only exists on the node that contains position + { + WALBERLA_ASSERT_FLOAT_EQUAL(squirmer->getSquirmerVelocity(), v0); + WALBERLA_ASSERT_FLOAT_EQUAL(squirmer->getSquirmerBeta(), beta); + WALBERLA_ASSERT_FLOAT_EQUAL(squirmer->getRadius(), R); + WALBERLA_ASSERT_FLOAT_EQUAL(squirmer->getPosition(), position); + WALBERLA_ASSERT_FLOAT_EQUAL(squirmer->getQuaternion(), q); + } + + WALBERLA_LOG_INFO_ON_ROOT("Checking result..."); + auto b1 = real_c(1.5) * v0; + auto b2 = beta * b1; + auto e = q.rotate(up).getNormalized(); + auto radius = R; + auto squirmer_pos = position; + + real_t abs_tolerance = real_c(0.0026); + real_t rel_tolerance = real_c(0.10); + + for ( auto blockIt = blocks->begin(); blockIt != blocks->end(); ++blockIt) + { + IBlock & block = *blockIt; + auto src = block.getData< PdfField_T >(pdfFieldID); + + auto flagField = block.getData<FlagField_T> (flagFieldID); + auto flag = flagField->getFlag(Fluid_Flag); + + WALBERLA_FOR_ALL_CELLS_XYZ(src, { + Vector3<real_t> pos; + blocks->getBlockLocalCellCenter( block, Cell(x,y,z), pos[0], pos[1], pos[2] ); + + if( flagField->isFlagSet(x, y, z, flag) ) //check for fluid/non-boundary + { + auto r = pos - squirmer_pos; + + auto v_ana = analytical_velocity(r, b1, b2, e, radius); + + // Superposition with the nearest neighbours (faces) + for( auto s = stencil::D3Q7::beginNoCenter(); s != stencil::D3Q7::end(); ++s ) + { + Vector3<real_t> imidpoint(squirmer_pos); + imidpoint[0] += real_c(s.cx() * int_c(L)); + imidpoint[1] += real_c(s.cy() * int_c(L)); + imidpoint[2] += real_c(s.cz() * int_c(L)); + v_ana += analytical_velocity( pos - imidpoint, b1, b2, e, radius ); + } + + if( !shortrun && r.length() > 2*radius ) // Exclude the volume around the squirmer, as the analytical solution is a far field solution only + { + auto v_data = src->getVelocity(x, y, z); + auto diff = v_data - v_ana; + + for( uint_t d = 0; d < 3; ++d ) + { + if( std::abs( diff[d] / v_ana[d] ) > rel_tolerance && std::abs( diff[d] ) > abs_tolerance ) + { + WALBERLA_LOG_DEVEL("Difference too large in " << Cell(x,y,z) << " (" << r.length() << "). Expected " << v_ana << ", got " << v_data << ", relative " << std::abs(diff[d] / v_ana[d]) << ", absolute " << std::abs(diff[d])); + } + } + } + + if( writevtk ) + { + // store the value into the PDF field so we can write it to VTK later + src->setToEquilibrium( x, y, z, v_ana ); + } + } + }); + } + + if (writevtk) + { + WALBERLA_LOG_INFO_ON_ROOT("Writing out reference VTK file..."); + auto pdfFieldVTKWriter = createFluidFieldVTKWriter( blocks, pdfFieldID, flagFieldID, "fluid_field_ref" ); + auto wf = vtk::writeFiles( pdfFieldVTKWriter ); + wf(); + } + + WALBERLA_LOG_INFO_ON_ROOT("Completed test."); + + return 0; +} -- GitLab