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| author | Claudius "keldu" Holeksa <mail@keldu.de> | 2026-07-05 15:59:23 +0200 |
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| committer | Claudius "keldu" Holeksa <mail@keldu.de> | 2026-07-05 15:59:23 +0200 |
| commit | c0549d71b2109f10c1238db8b22362e7826ba61b (patch) | |
| tree | 16cd5264fcc3afe912e1b1b67738c8940d6d1177 /modules/core/c++/collision.hpp | |
| parent | 9a3147bc79caf3c0fb1a9cdee29d156b5ff092c7 (diff) | |
| download | libs-lbm-c0549d71b2109f10c1238db8b22362e7826ba61b.tar.gz | |
Just rename from lib to modules
Diffstat (limited to 'modules/core/c++/collision.hpp')
| -rw-r--r-- | modules/core/c++/collision.hpp | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/modules/core/c++/collision.hpp b/modules/core/c++/collision.hpp new file mode 100644 index 0000000..023f61f --- /dev/null +++ b/modules/core/c++/collision.hpp @@ -0,0 +1,201 @@ +#pragma once + +#include "macroscopic.hpp" +#include "component.hpp" +#include "equilibrium.hpp" +#include "chunk.hpp" + +namespace kel { +namespace lbm { +namespace cmpt { +struct BGK {}; +struct BGKGuo {}; +} + +/** + * Standard BGK collision operator for LBM + */ +template<typename T, typename Descriptor, typename Encode> +class component<T, Descriptor, cmpt::BGK, Encode> { +private: + saw::data<T> relaxation_; + saw::data<T> frequency_; +public: + component(typename saw::native_data_type<T>::type relaxation__): + relaxation_{{relaxation__}}, + frequency_{saw::data<T>{1} / relaxation_} + {} + + component(const saw::data<T>& relaxation__): + relaxation_{relaxation__}, + frequency_{saw::data<T>{1} / relaxation_} + {} + + using Component = cmpt::BGK; + + /** + * Thoughts regarding automating order setup + */ + using access = cmpt::access_tuple< + cmpt::access<"dfs", 1, true, true, true> + >; + + /** + * Thoughts regarding automating order setup + */ + static constexpr saw::string_literal name = "collision"; + static constexpr saw::string_literal after = ""; + static constexpr saw::string_literal before = "streaming"; + + /** + * Raw setup + */ + template<typename CellFieldSchema> + void apply(const saw::data<CellFieldSchema, Encode>& field, saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>> index, saw::data<sch::UInt64> time_step) const { + bool is_even = ((time_step.get() % 2) == 0); + + // auto& dfs_f = (is_even) ? field.template get<"dfs">() : field.template get<"dfs_old">(); + auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">(); + + saw::data<sch::Scalar<T>> rho; + saw::data<sch::Vector<T,Descriptor::D>> vel; + compute_rho_u<T,Descriptor>(dfs_old_f.at(index),rho,vel); + auto eq = equilibrium<T,Descriptor>(rho,vel); + + for(uint64_t i = 0u; i < Descriptor::Q; ++i){ + dfs_old_f.at(index).at({i}) = dfs_old_f.at(index).at({i}) + frequency_ * (eq.at(i) - dfs_old_f.at(index).at({i})); + } + } + + template<typename CellFieldSchema, typename MacroFieldSchema> + void apply(const saw::data<CellFieldSchema, Encode>& field, const saw::data<MacroFieldSchema,Encode>& macros, saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>> index, saw::data<sch::UInt64> time_step) const { + bool is_even = ((time_step.get() % 2) == 0); + + // auto& dfs_f = (is_even) ? field.template get<"dfs">() : field.template get<"dfs_old">(); + auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">(); + + auto& rho_f = macros.template get<"density">(); + auto& vel_f = macros.template get<"velocity">(); + + saw::data<sch::Scalar<T>>& rho = rho_f.at(index); + saw::data<sch::Vector<T,Descriptor::D>>& vel = vel_f.at(index); + + compute_rho_u<T,Descriptor>(dfs_old_f.at(index),rho,vel); + + auto eq = equilibrium<T,Descriptor>(rho,vel); + + for(uint64_t i = 0u; i < Descriptor::Q; ++i){ + dfs_old_f.at(index).at({i}) = dfs_old_f.at(index).at({i}) + frequency_ * (eq.at(i) - dfs_old_f.at(index).at({i})); + } + } +}; + +template<typename T, typename Descriptor, typename Encode> +class component<T, Descriptor, cmpt::BGKGuo, Encode> { +private: + typename saw::native_data_type<T>::type relaxation_; + saw::data<T> frequency_; + saw::data<sch::Vector<T,Descriptor::D>> global_force_; +public: + component(typename saw::native_data_type<T>::type relaxation__): + relaxation_{relaxation__}, + frequency_{typename saw::native_data_type<T>::type(1) / relaxation_}, + global_force_{} + {} + + component( + typename saw::native_data_type<T>::type relaxation__, + saw::data<sch::Vector<T,Descriptor::D>>& global_force__ + ): + relaxation_{relaxation__}, + frequency_{typename saw::native_data_type<T>::type(1) / relaxation_}, + global_force_{global_force__} + {} + + using Component = cmpt::BGKGuo; + + using access = cmpt::access_tuple< + cmpt::access<"dfs", 1, true, true, true>, + cmpt::access<"force", 0, true, false> + >; + + /** + * Thoughts regarding automating order setup + */ + static constexpr saw::string_literal name = "collision"; + static constexpr saw::string_literal after = ""; + static constexpr saw::string_literal before = "streaming"; + + template<typename CellFieldSchema, typename MacroFieldSchema> + void apply(const saw::data<CellFieldSchema, Encode>& field, const saw::data<MacroFieldSchema,Encode>& macros, saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>> index, saw::data<sch::UInt64> time_step) const { + // void apply(saw::data<CellFieldSchema, Encode>& field, saw::data<sch::FixedArray<sch::UInt64, Descriptor::D>> index, saw::data<sch::UInt64> time_step){ + bool is_even = ((time_step.get() % 2) == 0); + + auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">(); + auto& dfs = dfs_old_f.at(index); + + auto& rho_f = macros.template get<"density">(); + auto& vel_f = macros.template get<"velocity">(); + + saw::data<sch::Scalar<T>>& rho = rho_f.at(index); + + auto& force_f = macros.template get<"force">(); + auto& force = force_f.at(index); + + auto total_force = force + global_force_; + + saw::data<sch::Scalar<T>> half; + half.at({}).set(0.5); + auto& vel = vel_f.at(index); + vel = vel + total_force * ( half / rho ); + + compute_rho_u<T,Descriptor>(dfs_old_f.at(index),rho,vel); + auto eq = equilibrium<T,Descriptor>(rho,vel); + + using dfi = df_info<T,Descriptor>; + + + saw::data<sch::Scalar<T>> dfi_inv_cs2; + dfi_inv_cs2.at({}).set(dfi::inv_cs2); + + + // auto vel = vel_f.at(index); + + for(uint64_t i = 0u; i < Descriptor::Q; ++i){ + // saw::data<T> ci_min_u{0}; + saw::data<sch::Vector<T,Descriptor::D>> ci; + for(uint64_t d = 0u; d < Descriptor::D; ++d){ + ci.at({{d}}).set(static_cast<typename saw::native_data_type<T>::type>(dfi::directions[i][d])); + } + auto ci_dot_u = saw::math::dot(ci,vel); + + // saw::data<sch::Vector<T,Descriptor::D>> F_i; + // F_i = f * ((c_i - u) * ics2 + <c_i,u> * c_i * ics2 * ics2) * w_i; + saw::data<sch::Scalar<T>> w; + w.at({}).set(dfi::weights[i]); + + /* + saw::data<sch::Scalar<T>> F_i_sum; + for(uint64_t d = 0u; d < Descriptor::D; ++d){ + saw::data<sch::Scalar<T>> F_i_d; + F_i_d.at({}) = F_i.at({{d}}); + F_i_sum = F_i_sum + F_i_d; + } + */ + auto term1 = (ci-vel) * dfi_inv_cs2; + auto term2 = ci * (ci_dot_u * dfi_inv_cs2 * dfi_inv_cs2); + + auto force_projection = saw::math::dot(term1 + term2, total_force); + + auto F_i = w * force_projection; + + dfs.at({i}) = dfs.at({i}) + + frequency_ + * (eq.at(i) - dfs.at({i}) ) + + F_i.at({}) + * (saw::data<T>{1} - saw::data<T>{0.5f} * frequency_); + } + } +}; +} +} |
