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authorClaudius "keldu" Holeksa <mail@keldu.de>2025-07-23 17:25:25 +0200
committerClaudius "keldu" Holeksa <mail@keldu.de>2025-07-23 17:25:25 +0200
commit163eb5b4436876d4163cf6aa33ce633b5b7957d0 (patch)
tree897ed2352f902be8ebdf3c9f28fe549645c5587f
parentc7b106cab28ecfdb1c336728a104f6dcc7343a70 (diff)
Adding channel
-rw-r--r--examples/SConscript8
-rw-r--r--examples/poiseulle_channel_2d.cpp422
-rw-r--r--examples/poiseulle_particles_2d.cpp14
3 files changed, 442 insertions, 2 deletions
diff --git a/examples/SConscript b/examples/SConscript
index 9bac1f0..5ec416b 100644
--- a/examples/SConscript
+++ b/examples/SConscript
@@ -38,12 +38,18 @@ examples_objects = [];
examples_env.add_source_files(examples_objects, ['poiseulle_2d.cpp'], shared=False);
examples_env.poiseulle_2d = examples_env.Program('#bin/poiseulle_2d', [env.library_static, examples_objects]);
+# Poiseulle Channel 2D
+examples_objects = [];
+examples_env.add_source_files(examples_objects, ['poiseulle_channel_2d.cpp'], shared=False);
+examples_env.poiseulle_channel_2d = examples_env.Program('#bin/poiseulle_channel_2d', [env.library_static, examples_objects]);
+
# Set Alias
env.examples = [
examples_env.meta_2d,
examples_env.cavity_2d,
# examples_env.particle_ibm_2d
- examples_env.poiseulle_2d
+ examples_env.poiseulle_2d,
+ examples_env.poiseulle_channel_2d
];
env.Alias('examples', env.examples);
diff --git a/examples/poiseulle_channel_2d.cpp b/examples/poiseulle_channel_2d.cpp
new file mode 100644
index 0000000..376ba84
--- /dev/null
+++ b/examples/poiseulle_channel_2d.cpp
@@ -0,0 +1,422 @@
+#include "../c++/lbm.hpp"
+#include "../c++/collision.hpp"
+#include "../c++/boundary.hpp"
+#include "../c++/iterator.hpp"
+
+#include <forstio/codec/data.hpp>
+
+namespace kel {
+namespace lbm {
+namespace sch {
+using namespace saw::schema;
+
+/**
+ * Basic distribution function
+ * Base type
+ * D
+ * Q
+ * Scalar factor
+ * D factor
+ * Q factor
+ */
+using T = Float32;
+using D2Q5 = Descriptor<2u,5u>;
+using D2Q9 = Descriptor<2u,9u>;
+
+template<typename Desc>
+using DfCell = Cell<T, Desc, 0u, 0u, 1u>;
+
+template<typename Desc>
+using CellInfo = Cell<UInt8, D2Q9, 1u, 0u, 0u>;
+
+/**
+ * Basic type for simulation
+ */
+template<typename Desc>
+using CellStruct = Struct<
+ Member<DfCell<Desc>, "dfs">,
+ Member<DfCell<Desc>, "dfs_old">,
+ Member<CellInfo<Desc>, "info">
+>;
+
+template<typename T, uint64_t D>
+using MacroStruct = Struct<
+ Member<FixedArray<T,D>, "velocity">,
+ Member<T, "pressure">
+>;
+
+template<typename T>
+using GeometryStruct = Struct<
+ Member<T, "info">
+>;
+
+using CavityFieldD2Q9 = CellField<D2Q9, CellStruct<D2Q9>>;
+}
+
+namespace cmpt {
+template<bool East>
+struct PressureBoundaryRestrictedVelocityTo {};
+}
+
+/**
+ * This is massively hacky and expects a lot of conditions
+ * Either this or mirrored along the horizontal line works
+ *
+ * 0 - 2 - 2
+ * 0 - 3 - 1
+ * 0 - 3 - 1
+ * .........
+ * 0 - 3 - 1
+ * 0 - 2 - 2
+ *
+ */
+template<typename FP,typename Descriptor, bool East>
+struct component<FP,Descriptor, cmpt::PressureBoundaryRestrictedVelocityTo<East>> {
+private:
+ saw::data<FP> pressure_setting_;
+ saw::data<FP> rho_setting_;
+public:
+ component(const saw::data<FP>& pressure_setting__):
+ pressure_setting_{pressure_setting__},
+ rho_setting_{pressure_setting__ * df_info<FP,Descriptor>::inv_cs2}
+ {}
+
+ template<typename CellFieldSchema>
+ void apply(saw::data<CellFieldSchema>& field, saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>> index, uint64_t time_step){
+ using dfi = df_info<FP,Descriptor>;
+
+ bool is_even = ((time_step % 2) == 0);
+ auto& cell = field(index);
+
+ auto& info = cell.template get<"info">();
+ if(info({0u}).get() == 0u){
+ return;
+ }
+ auto& dfs_old = (is_even) ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+ auto& dfs = (not is_even) ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+
+ /**
+ * Sum all known DFs
+ */
+ saw::data<FP> sum_df{0};
+ for(saw::data<sch::UInt64> k{0u}; k < saw::data<sch::UInt64>{Descriptor::Q}; ++k){
+ auto c_k = dfi::directions[k.get()];
+ auto& cell_n = field({{index.at({0u})+c_k[0u], index.at({1u})+c_k[1u]}});
+ auto& info_n = cell_n.template get<"info">();
+ auto info_n_val = info_n({0u});
+ auto k_opp = dfi::opposite_index[k.get()];
+
+ if(info_n_val.get() > 0u){
+ sum_df += dfs_old({k_opp});
+ }
+ }
+ /**
+ * Get the sum of the unknown dfs and precalculate the direction
+ */
+ constexpr int known_dir = East ? 1 : -1;
+ auto sum_unknown_dfs = (rho_setting_ - sum_df) * saw::data<FP>{known_dir};
+
+ for(saw::data<sch::UInt64> k{0u}; k < saw::data<sch::UInt64>{Descriptor::Q}; ++k){
+ auto c_k = dfi::directions[k.get()];
+ auto& cell_n = field({{index.at({0u})+c_k[0u], index.at({1u})+c_k[1u]}});
+ auto& info_n = cell_n.template get<"info">();
+ auto info_n_val = info_n({0u});
+ auto k_opp = dfi::opposite_index[k.get()];
+
+ if(info_n_val.get() > 0u){
+ sum_unknown_dfs += dfs_old({k}) * c_k[0u];
+ }
+ }
+
+ auto vel_x = sum_unknown_dfs / rho_setting_;
+
+ if constexpr (East) {
+ dfs_old({2u}) = dfs_old({1u}) + saw::data<FP>{2.0 / 3.0} * rho_setting_ * vel_x;
+ dfs_old({6u}) = dfs_old({5u}) + saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({4u}) - dfs_old({3u}));
+ dfs_old({8u}) = dfs_old({7u}) + saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({3u}) - dfs_old({4u}));
+ }else if constexpr (not East){
+ dfs_old({1u}) = dfs_old({2u}) - saw::data<FP>{2.0 / 3.0} * rho_setting_ * vel_x;
+ dfs_old({5u}) = dfs_old({6u}) - saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({3u}) - dfs_old({4u}));
+ dfs_old({7u}) = dfs_old({8u}) - saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({4u}) - dfs_old({3u}));
+ }
+ }
+};
+}
+}
+
+void set_geometry(saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt){
+ using namespace kel::lbm;
+
+ auto meta = latt.meta();
+
+ /**
+ * Set ghost
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ info({0u}).set(0u);
+
+ }, {{0u,0u}}, meta);
+
+ /**
+ * Set wall
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ info({0u}).set(2u);
+
+ }, {{0u,0u}}, meta, {{1u,1u}});
+
+ /**
+ * Set fluid
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ info({0u}).set(1u);
+
+ }, {{0u,0u}}, meta, {{2u,2u}});
+
+ /**
+ * Set inflow
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ info({0u}).set(3u);
+
+ }, {{1u,0u}}, {{2u,meta.at({1u})}}, {{0u,2u}});
+
+ /**
+ * Set outflow
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ info({0u}).set(4u);
+
+ }, {{meta.at({0u})-2u,0u}}, {{meta.at({0u})-1u, meta.at({1u})}}, {{0u,2u}});
+
+ /**
+ * Set channel wall
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ saw::data<sch::FixedArray<sch::UInt64,2u>> area{{meta.at({0u})-8u, meta.at({1u})-2u}};
+ double ch_width = area.at({1u}).get() * (0.6 * 0.5);
+ double ch_length = area.at({0u}).get() * (0.8 * 0.5);
+
+ saw::data<sch::FixedArray<sch::UInt64,2u>> middle{{meta.at({0u})/2u, meta.at({1u})/2u}};
+
+ double r = ch_length + ch_width * ch_width * 0.25 / ch_length;
+
+ double top_pos = middle.at({1u}).get() + r;
+ double bot_pos = middle.at({1u}).get() - r;
+ double mid = middle.at({0u}).get();
+
+ double r_2 = r*r;
+ double dist_top = (top_pos - index.at({1u}).get());
+ double dist_bot = (bot_pos - index.at({1u}).get());
+ double dist_mid = (mid - index.at({0u}).get());
+
+ double dist_top_sq = dist_top * dist_top + dist_mid * dist_mid;
+ double dist_bot_sq = dist_bot * dist_bot + dist_mid * dist_mid;
+
+ if(dist_top_sq < r_2 or dist_bot_sq < r_2){
+ info({0u}).set(2u);
+ }
+
+ }, {{0u,0u}}, meta, {{4u,1u}});
+}
+
+void set_initial_conditions(saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt){
+ using namespace kel::lbm;
+
+ saw::data<sch::T> rho{1.0};
+ saw::data<sch::FixedArray<sch::T,sch::D2Q9::D>> vel{{0.0,0.0}};
+ auto eq = equilibrium<sch::T,sch::D2Q9>(rho, vel);
+
+ auto meta = latt.meta();
+
+ /**
+ * Set distribution
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& dfs = cell.template get<"dfs">();
+ auto& dfs_old = cell.template get<"dfs_old">();
+
+ for(saw::data<sch::UInt64> k = 0; k < saw::data<sch::UInt64>{sch::D2Q9::Q}; ++k){
+ dfs(k) = eq.at(k);
+ dfs_old(k) = eq.at(k);
+ }
+
+ }, {{0u,0u}}, meta);
+}
+
+void lbm_step(
+ saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt,
+ uint64_t time_step
+){
+ using namespace kel::lbm;
+ using dfi = df_info<sch::T,sch::D2Q9>;
+
+ bool even_step = ((time_step % 2u) == 0u);
+ /**
+ * 1. Relaxation parameter \tau
+ */
+ component<sch::T, sch::D2Q9, cmpt::BGK> coll{0.5384};
+ component<sch::T, sch::D2Q9, cmpt::BounceBack> bb;
+ component<sch::T, sch::D2Q9, cmpt::PressureBoundaryRestrictedVelocityTo<true>> inlet{1.01 * dfi::cs2};
+ component<sch::T, sch::D2Q9, cmpt::PressureBoundaryRestrictedVelocityTo<false>> outlet{1.0 * dfi::cs2};
+
+ auto meta = latt.meta();
+
+ /**
+ * Collision
+ */
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& info = cell.template get<"info">();
+
+ auto& dfs = cell.template get<"dfs">();
+ auto& dfs_old = cell.template get<"dfs_old">();
+
+ switch(info({0u}).get()){
+ case 1u: {
+ coll.apply(latt, index, time_step);
+ break;
+ }
+ case 2u: {
+ bb.apply(latt, index, time_step);
+ break;
+ }
+ case 3u: {
+ inlet.apply(latt, index, time_step);
+ break;
+ }
+ case 4u: {
+ outlet.apply(latt, index, time_step);
+ break;
+ }
+ default:
+ break;
+ }
+
+ }, {{0u,0u}}, meta);
+
+ // Stream
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = latt(index);
+ auto& df_new = even_step ? cell.template get<"dfs">() : cell.template get<"dfs_old">();
+ auto& info_new = cell.template get<"info">();
+
+ if(info_new({0u}).get() > 0u){
+ for(uint64_t k = 0u; k < sch::D2Q9::Q; ++k){
+ auto dir = dfi::directions[dfi::opposite_index[k]];
+ auto& cell_dir_old = latt({{index.at({0u})+dir[0],index.at({1u})+dir[1]}});
+
+ auto& df_old = even_step ? cell_dir_old.template get<"dfs_old">() : cell_dir_old.template get<"dfs">();
+
+ df_new({k}) = df_old({k});
+ }
+ }
+ }, {{0u,0u}}, meta);
+}
+
+int main(int argc, char** argv){
+ using namespace kel::lbm;
+ using dfi = df_info<sch::T,sch::D2Q9>;
+
+ std::string_view cfg_file_name = "config.json";
+ if(argc > 1){
+ cfg_file_name = argv[1];
+ }
+
+ auto eo_conf = load_lbm_config<sch::Float64,sch::Descriptor<2u,9u>>(cfg_file_name);
+ if(eo_conf.is_error()){
+ auto& err = eo_conf.get_error();
+ std::cerr<<"[Error]: "<<err.get_category();
+ auto err_msg = err.get_message();
+ if(!err_msg.empty()){
+ std::cerr<<" - "<<err_msg;
+ }
+ std::cerr<<std::endl;
+
+ return err.get_id();
+ }
+
+ auto& conf = eo_conf.get_value();
+
+ converter<sch::Float64> conv {
+ {conf.template get<"delta_x">()},
+ {conf.template get<"delta_t">()}
+ };
+
+ print_lbm_meta<sch::Float64,sch::Descriptor<2u,9u>>(conv, {conf.template get<"kinematic_viscosity">()});
+
+ saw::data<sch::FixedArray<sch::UInt64,sch::D2Q9::D>> dim{{1024u, 128u}};
+ saw::data<sch::CavityFieldD2Q9, saw::encode::Native> lattice{dim};
+ auto meta = lattice.meta();
+
+ /**
+ * Setup geometry
+ */
+ set_geometry(lattice);
+
+ {
+
+ saw::data<sch::Array<sch::GeometryStruct<sch::T>, sch::D2Q9::D>> geo{dim};
+
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = lattice(index);
+ auto& info = cell.template get<"info">();
+
+ geo(index).template get<"info">().set(info({0u}).get());
+ }, {{0u,0u}}, dim);
+
+ std::string vtk_f_name{"tmp/geometry.vtk"};
+ write_vtk_file(vtk_f_name, geo);
+ }
+
+ /**
+ * Setup DFs
+ */
+ set_initial_conditions(lattice);
+
+ saw::data<sch::Array<sch::MacroStruct<sch::T,sch::D2Q9::D>,sch::D2Q9::D>> macros{dim};
+
+ for(uint64_t i = 0u; i < 4096u*16u; ++i){
+ bool even_step = ((i % 2u) == 0u);
+
+ {
+ // Stream
+ iterate_over([&](const saw::data<sch::FixedArray<sch::UInt64,2u>>& index){
+ auto& cell = lattice(index);
+ auto& dfs = even_step ? cell.template get<"dfs">() : cell.template get<"dfs_old">();
+
+ auto& rho = macros.at(index).template get<"pressure">();
+ auto& vel = macros.at(index).template get<"velocity">();
+ compute_rho_u<sch::T,sch::D2Q9>(dfs,rho,vel);
+ rho = rho * saw::data<sch::T>{dfi::cs2};
+
+ }, {{0u,0u}}, meta);
+ std::string vtk_f_name{"tmp/poiseulle_2d_"};
+ vtk_f_name += std::to_string(i) + ".vtk";
+ write_vtk_file(vtk_f_name, macros);
+ }
+
+ lbm_step(lattice, i);
+ }
+
+ return 0;
+}
diff --git a/examples/poiseulle_particles_2d.cpp b/examples/poiseulle_particles_2d.cpp
index 3e636f9..d0310e4 100644
--- a/examples/poiseulle_particles_2d.cpp
+++ b/examples/poiseulle_particles_2d.cpp
@@ -3,6 +3,8 @@
#include "../c++/boundary.hpp"
#include "../c++/iterator.hpp"
+#include "../c++/particle/particle.hpp"
+
#include <forstio/codec/data.hpp>
namespace kel {
@@ -36,7 +38,8 @@ template<typename Desc>
using CellStruct = Struct<
Member<DfCell<Desc>, "dfs">,
Member<DfCell<Desc>, "dfs_old">,
- Member<CellInfo<Desc>, "info">
+ Member<CellInfo<Desc>, "info">,
+ Member<Cell<UInt8, D2Q9, 1u, 0u, 0u>, "particle_mask">
>;
template<typename T, uint64_t D>
@@ -335,6 +338,15 @@ int main(int argc, char** argv){
saw::data<sch::CavityFieldD2Q9, saw::encode::Native> lattice{dim};
auto meta = lattice.meta();
+ particle_system<sch::T, sch::D2Q9::D> part_sys;
+ {
+ saw::data<sch::Particle<sch::T, sch::D2Q9::D>> part;
+ auto eov = part_sys.add(std::move(part));
+ if(eov.is_error()){
+ return eov.get_error().get_id();
+ }
+ }
+
/**
* Setup geometry
*/