summaryrefslogtreecommitdiff
path: root/examples/cavity_2d
diff options
context:
space:
mode:
authorClaudius "keldu" Holeksa <mail@keldu.de>2025-09-09 11:02:12 +0200
committerClaudius "keldu" Holeksa <mail@keldu.de>2025-09-09 11:02:12 +0200
commit7ff6ea3bde6eb1d3b55c558303c48e065c38199b (patch)
tree6da790a967d7fe73f696dd3de25e18690a5e1d55 /examples/cavity_2d
parent3fa7dcb5684504dc99d14d2dc003876151636834 (diff)
Trying to isolate nix builds a bit
Diffstat (limited to 'examples/cavity_2d')
-rw-r--r--examples/cavity_2d/.nix/derivation.nix36
-rw-r--r--examples/cavity_2d/SConscript41
-rw-r--r--examples/cavity_2d/SConstruct80
-rw-r--r--examples/cavity_2d/cavity_2d.cpp436
4 files changed, 593 insertions, 0 deletions
diff --git a/examples/cavity_2d/.nix/derivation.nix b/examples/cavity_2d/.nix/derivation.nix
new file mode 100644
index 0000000..a98795b
--- /dev/null
+++ b/examples/cavity_2d/.nix/derivation.nix
@@ -0,0 +1,36 @@
+{ lib
+, stdenv
+, scons
+, clang-tools
+, forstio
+, pname
+, version
+}:
+
+stdenv.mkDerivation {
+ inherit pname version;
+ src = ./..;
+
+ nativeBuildInputs = [
+ scons
+ clang-tools
+ ];
+
+ buildInputs = [
+ forstio.core
+ forstio.async
+ forstio.codec
+ forstio.codec-unit
+ forstio.codec-json
+ ];
+
+ doCheck = true;
+ checkPhase = ''
+ scons test
+ ./bin/tests
+ '';
+
+ preferLocalBuild = true;
+
+ outputs = [ "out" "dev" ];
+}
diff --git a/examples/cavity_2d/SConscript b/examples/cavity_2d/SConscript
new file mode 100644
index 0000000..077fb99
--- /dev/null
+++ b/examples/cavity_2d/SConscript
@@ -0,0 +1,41 @@
+#!/bin/false
+
+import os
+import os.path
+import glob
+
+
+Import('env')
+
+dir_path = Dir('.').abspath
+
+# Environment for base library
+cavity2d_env = examples_env.Clone();
+
+examples_env.sources = sorted(glob.glob(dir_path + "/*.cpp"))
+examples_env.headers = sorted(glob.glob(dir_path + "/*.hpp"))
+
+env.sources += examples_env.sources;
+env.headers += examples_env.headers;
+
+# Cavity2D
+examples_objects = [];
+examples_env.add_source_files(examples_objects, ['cavity_2d.cpp'], shared=False);
+examples_env.cavity_2d = examples_env.Program('#bin/cavity_2d', [env.library_static, examples_objects]);
+
+# Set Alias
+env.examples = [
+ examples_env.meta_2d,
+# examples_env.cavity_2d,
+# examples_env.cavity_3d,
+# examples_env.particle_ibm_2d
+ examples_env.poiseulle_2d,
+ examples_env.poiseulle_channel_2d,
+ examples_env.poiseulle_particles_channel_2d
+];
+env.Alias('examples', env.examples);
+
+if env["build_examples"]:
+ env.targets += ['examples'];
+ env.Install('$prefix/bin/', env.examples);
+#endif
diff --git a/examples/cavity_2d/SConstruct b/examples/cavity_2d/SConstruct
new file mode 100644
index 0000000..fc60882
--- /dev/null
+++ b/examples/cavity_2d/SConstruct
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import os.path
+import glob
+import re
+
+
+if sys.version_info < (3,):
+ def isbasestring(s):
+ return isinstance(s,basestring)
+else:
+ def isbasestring(s):
+ return isinstance(s, (str,bytes))
+
+def add_kel_source_files(self, sources, filetype, lib_env=None, shared=False, target_post=""):
+
+ if isbasestring(filetype):
+ dir_path = self.Dir('.').abspath
+ filetype = sorted(glob.glob(dir_path+"/"+filetype))
+
+ for path in filetype:
+ target_name = re.sub( r'(.*?)(\.cpp|\.c\+\+)', r'\1' + target_post, path )
+ if shared:
+ target_name+='.os'
+ sources.append( self.SharedObject( target=target_name, source=path ) )
+ else:
+ target_name+='.o'
+ sources.append( self.StaticObject( target=target_name, source=path ) )
+ pass
+
+def isAbsolutePath(key, dirname, env):
+ assert os.path.isabs(dirname), "%r must have absolute path syntax" % (key,)
+
+env_vars = Variables(
+ args=ARGUMENTS
+)
+
+env_vars.Add('prefix',
+ help='Installation target location of build results and headers',
+ default='/usr/local/',
+ validator=isAbsolutePath
+)
+
+env_vars.Add('build_examples',
+ help='If examples should be built',
+ default="true"
+)
+
+env=Environment(ENV=os.environ, variables=env_vars, CPPPATH=[],
+ CPPDEFINES=['SAW_UNIX'],
+ CXXFLAGS=[
+ '-std=c++20',
+ '-g',
+ '-Wall',
+ '-Wextra'
+ ],
+ LIBS=[
+ 'forstio-core',
+ 'forstio-codec'
+ ]
+);
+env.__class__.add_source_files = add_kel_source_files
+env.Tool('compilation_db');
+env.cdb = env.CompilationDatabase('compile_commands.json');
+
+env.objects = [];
+env.sources = [];
+env.headers = [];
+env.targets = [];
+
+Export('env')
+SConscript('SConscript')
+
+env.Alias('cdb', env.cdb);
+env.Alias('all', [env.targets]);
+env.Default('all');
+
+env.Alias('install', '$prefix')
diff --git a/examples/cavity_2d/cavity_2d.cpp b/examples/cavity_2d/cavity_2d.cpp
new file mode 100644
index 0000000..e228a06
--- /dev/null
+++ b/examples/cavity_2d/cavity_2d.cpp
@@ -0,0 +1,436 @@
+#include "../c++/descriptor.hpp"
+#include "../c++/macroscopic.hpp"
+#include "../c++/lbm.hpp"
+#include "../c++/component.hpp"
+#include "../c++/collision.hpp"
+#include "../c++/boundary.hpp"
+
+#include <forstio/codec/data.hpp>
+
+#include <iostream>
+#include <fstream>
+#include <cmath>
+
+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">
+>;
+
+using CavityFieldD2Q9 = CellField<D2Q9, CellStruct<D2Q9>>;
+}
+
+
+/*
+template<typename T, typename Encode>
+class df_cell_view;
+*/
+/**
+ * Minor helper for the AA-Pull Pattern, so I can use only one lattice
+ *
+ * Am I sure I want to use AA this way?
+ * Esoteric Twist technically reduces the needed memory access footprint
+ */
+/*
+template<typename Desc, size_t SN, size_t DN, size_t QN, typename Encode>
+class df_cell_view<sch::Cell<sch::T, Desc, SN, DN, QN>, Encode> {
+public:
+ using Schema = sch::Cell<sch::T,Desc,SN,DN,QN>;
+private:
+ std::array<std::decay_t<typename saw::native_data_type<sch::T>::type>*, QN> view_;
+public:
+ df_cell_view(const std::array<std::decay_t<typename saw::native_data_type<sch::T>::type>*, QN>& view):
+ view_{view}
+ {}
+};
+*/
+namespace cmpt {
+struct MovingWall {};
+}
+
+/**
+ * Full-Way moving wall Bounce back, something is not right here.
+ * Technically it should reflect properly.
+ */
+template<typename Desc>
+class component<sch::T, Desc, cmpt::MovingWall> {
+public:
+ std::array<typename saw::native_data_type<sch::T>::type, Desc::D> lid_vel;
+
+public:
+ void apply(
+ saw::data<sch::DfCell<Desc>>& dfs
+ ){
+ using dfi = df_info<sch::T,Desc>;
+
+ // Technically use .copy()
+ /*
+ auto dfs_cpy = dfs;
+
+ for(uint64_t i = 0u; i < Desc::Q; ++i){
+ dfs({dfi::opposite_index.at(i)}) = dfs_cpy({i}) - 2.0 * dfi::weights[i] * 1.0 * ( lid_vel[0] * dfi::directions[i][0] + lid_vel[1] * dfi::directions[i][1]) * dfi::inv_cs2;
+ }
+ */
+ }
+};
+}
+}
+
+constexpr size_t dim_size = 2;
+constexpr size_t dim_x = 128;
+constexpr size_t dim_y = 128;
+
+
+template<typename Func>
+void apply_for_cells(Func&& func, saw::data<kel::lbm::sch::CavityFieldD2Q9>& dat){
+ for(std::size_t i = 0; i < dat.meta().at({1u}).get(); ++i){
+ for(std::size_t j = 0; j < dat.meta().at({0u}).get(); ++j){
+ saw::data<saw::schema::UInt64> di{i};
+ saw::data<saw::schema::UInt64> dj{j};
+ auto& cell_v = dat({{dj,di}});
+ func(cell_v, j, i);
+ }
+ }
+}
+
+void set_geometry(saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt){
+ using namespace kel::lbm;
+ apply_for_cells([](auto& cell, std::size_t i, std::size_t j){
+ uint8_t val = 0;
+ if(j == 1){
+ val = 2u;
+ }
+ if(i == 1 || (i+2) == dim_x || (j+2) == dim_y){
+ val = 3u;
+ }
+ if(i > 1 && (i+2) < dim_x && j > 1 && (j+2) < dim_y){
+ val = 1u;
+ }
+ if(i == 0 || j == 0 || (i+1) == dim_x || (j+1) == dim_y){
+ val = 0u;
+ }
+ cell.template get<"info">()(0u).set(val);
+ }, latt);
+}
+
+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);
+
+ apply_for_cells([&eq](auto& cell, std::size_t i, std::size_t j){
+ (void) i;
+ (void) j;
+ auto& dfs = cell.template get<"dfs">();
+ auto& dfs_old = cell.template get<"dfs_old">();
+ auto info = cell.template get<"info">()(0u).get();
+ for(uint64_t k = 0; k < sch::D2Q9::Q; ++k){
+ dfs(k) = eq.at({k});
+ dfs_old(k) = eq.at({k});
+ }
+ }, latt);
+ }
+
+ {
+ saw::data<sch::FixedArray<sch::T,sch::D2Q9::D>> vel{{0.1,0.0}};
+ auto eq = equilibrium<sch::T,sch::D2Q9>(rho, vel);
+
+ apply_for_cells([&eq](auto& cell, std::size_t i, std::size_t j){
+ (void) i;
+ (void) j;
+ auto& dfs = cell.template get<"dfs">();
+ auto& dfs_old = cell.template get<"dfs_old">();
+ auto info = cell.template get<"info">()(0u).get();
+ if(info == 2u){
+ for(uint64_t k = 0; k < sch::D2Q9::Q; ++k){
+ dfs(k) = eq.at({k});
+ dfs_old(k) = eq.at({k});
+ }
+ }
+ }, latt);
+ }
+}
+
+void lbm_step(
+ saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt,
+ bool even_step,
+ uint64_t time_step
+){
+ using namespace kel::lbm;
+ using dfi = df_info<sch::T,sch::D2Q9>;
+
+ /**
+ * 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::MovingWall> bb_lid;
+ bb_lid.lid_vel = {0.1,0.0};
+
+ auto meta = latt.meta();
+
+ // Collide
+ for(saw::data<sch::UInt64> i{0u}; i < meta.at(0u); ++i){
+ for(saw::data<sch::UInt64> j{0u}; j < meta.at(1u); ++j ){
+ auto& cell = latt({{i,j}});
+ auto& info = cell.template get<"info">();
+
+ switch(info({0u}).get()){
+ case 1u: {
+ coll.apply(latt, {{i,j}}, time_step);
+ break;
+ }
+ case 2u: {
+ auto& df = even_step ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+ bb_lid.apply(df);
+ break;
+ }
+ case 3u: {
+ bb.apply(latt, {{i,j}}, time_step);
+ break;
+ }
+ default:
+ break;
+ }
+ }
+ }
+
+ // Stream
+ for(uint64_t i = 1u; (i+1u) < latt.template get_dim_size<0>().get(); ++i){
+ for(uint64_t j = 1u; (j+1u) < latt.template get_dim_size<1>().get(); ++j){
+ auto& cell = latt({{i,j}});
+ 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 && info_new({0u}).get() != 2u){
+ for(uint64_t k = 0u; k < sch::D2Q9::Q; ++k){
+ auto dir = dfi::directions[dfi::opposite_index[k]];
+ auto& cell_dir_old = latt({{i+dir[0],j+dir[1]}});
+
+ auto& df_old = even_step ? cell_dir_old.template get<"dfs_old">() : cell_dir_old.template get<"dfs">();
+ auto& info_old = cell_dir_old.template get<"info">();
+
+ if( info_old({0}).get() == 2u ){
+ auto& df_old_loc = even_step ? latt({{i,j}}).template get<"dfs_old">() : latt({{i,j}}).template get<"dfs">();
+ df_new({k}) = df_old_loc({dfi::opposite_index.at(k)}) - 2.0 * dfi::inv_cs2 * dfi::weights.at(k) * 1.0 * ( bb_lid.lid_vel[0] * dir[0] + bb_lid.lid_vel[1] * dir[1]);
+ // dfs({dfi::opposite_index.at(i)}) = dfs_cpy({i}) - 2.0 * dfi::weights[i] * 1.0 * ( lid_vel[0] * dfi::directions[i][0] + lid_vel[1] * dfi::directions[i][1]) * dfi::inv_cs2;
+ } else {
+ df_new({k}) = df_old({k});
+ }
+ }
+ }
+ }
+ }
+}
+
+int main(){
+ using namespace kel::lbm;
+
+ saw::data<sch::FixedArray<sch::UInt64,sch::D2Q9::D>> dim{{dim_x, dim_y}};
+
+ saw::data<sch::CavityFieldD2Q9, saw::encode::Native> lattice{dim};
+
+ converter<sch::T> conv{
+ {0.1},
+ {0.1}
+ };
+
+ print_lbm_meta<sch::T, sch::D2Q9>(conv, {1e-3});
+
+ //auto& df_field = lattices.at(0).template get<"dfs">();
+ //for(uint64_t i = 0; i < df_field.get_dim_size<0u>(); ++i){
+ // lattices.at(i) = {dim_x, dim_y};
+ //}
+
+ /**
+ * Set meta information describing what this cell is
+ */
+ set_geometry(lattice);
+
+ /**
+ *
+ */
+ set_initial_conditions(lattice);
+
+ /**
+ * Timeloop
+ */
+
+ /**
+ * Print basic setup info
+ */
+ apply_for_cells([](auto& cell, std::size_t i, std::size_t j){
+ // Not needed
+ (void) j;
+ std::cout<<(static_cast<uint32_t>(cell.template get<"info">()({0}).get()));
+ if( (i+1) < dim_x){
+ std::cout<<" ";
+ }else{
+ std::cout<<"\n";
+ }
+ }, lattice);
+
+ uint64_t lattice_steps = 512000u;
+ bool even_step = true;
+
+ uint64_t print_every = 256u;
+ uint64_t file_no = 0u;
+
+ saw::data<sch::Array<sch::MacroStruct<sch::T,sch::D2Q9::D>,sch::D2Q9::D>> macros{dim};
+
+ for(uint64_t step = 0; step < lattice_steps; ++step){
+
+ if(step % print_every == 0u){
+ std::cout<<"\n";
+ typename saw::native_data_type<sch::T>::type sum = 0.0;
+
+
+ apply_for_cells([&](auto& cell, std::size_t i, std::size_t j){
+ auto& dfs = cell.template get<"dfs">();
+ typename saw::native_data_type<sch::T>::type rho;
+ std::array<typename saw::native_data_type<sch::T>::type, sch::D2Q9::D> vel;
+ compute_rho_u<sch::T,sch::D2Q9>(dfs,rho,vel);
+
+ if(i > 1 && (i+2) < dim_x && j > 1 && (j+2) < dim_y){
+ sum += rho;
+ }
+ auto angle = std::atan2(vel[1],vel[0]);
+ double vel_mag = vel[1] * vel[1] + vel[0] * vel[0];
+
+ auto dir_char = [&]() -> std::string_view {
+ /**
+ * Flipped y due to print order
+ */
+ constexpr auto pi = M_PI;
+ return "■";
+ if(vel_mag < 1e-4){
+ return "•";
+ }
+ if(angle > 7.0 / 8.0 * pi){
+ return "←";
+ }
+ if(angle > 5.0 / 8.0 * pi){
+ return "↙";
+ }
+ if(angle > 3.0 / 8.0 * pi){
+ return "↓";
+ }
+ if(angle > 1.0 / 8.0 * pi){
+ return "↘";
+ }
+ if(angle > -1.0 / 8.0 * pi){
+ return "→";
+ }
+ if(angle > -3.0 / 8.0 * pi){
+ return "↗";
+ }
+ if(angle > -5.0 / 8.0 * pi){
+ return "↑";
+ }
+ if(angle > -7.0 / 8.0 * pi){
+ return "↖";
+ }
+ return "←";
+ }();
+
+ std::array<uint32_t,3u> rgb_start{64,64,255};
+ std::array<uint32_t,3u> rgb_stop{255,64,64};
+ std::array<uint32_t,3u> rgb_middle{255,255,255};
+
+
+ auto col_interpol = [&](){
+ std::array<uint32_t, 3u> rgb_interpol = rgb_start;
+ double vel_mag_cut = std::min(1.0,std::max(vel_mag/(0.07*0.07),0.0));
+
+ if(vel_mag_cut < 0.5){
+ uint32_t vel_mag_i = static_cast<uint32_t>(2.0 * vel_mag_cut * 256);
+ for(uint8_t i = 0u; i < 3u; ++i){
+ rgb_interpol[i] = (rgb_middle[i] * vel_mag_i + (256-vel_mag_i) * rgb_start[i]) / 256;
+ }
+ }else{
+ uint32_t vel_mag_i = static_cast<uint32_t>((2.0*(vel_mag_cut-0.5)) * 256);
+ for(uint8_t i = 0u; i < 3u; ++i){
+ rgb_interpol[i] = (rgb_stop[i] * vel_mag_i + (256-vel_mag_i) * rgb_middle[i]) / 256;
+ }
+ }
+ return rgb_interpol;
+ };
+ auto rgb_interpol = col_interpol();
+
+ std::cout<<"\x1b[38;2;"<<rgb_interpol[0]<<";"<<rgb_interpol[1]<<";"<<rgb_interpol[2]<<"m"<<dir_char;
+ if( (i+1) < dim_x){
+ std::cout<<" ";
+ }else{
+ std::cout<<"\n";
+ }
+ }, lattice);
+ std::cout<<"\x1b[38;2;255;255;255m";
+
+ /// std::cout<<"Average rho: "<<(sum / ((dim_x-4)*(dim_y-4)))<<std::endl;
+ std::cout.flush();
+
+ apply_for_cells([&](auto& cell, std::size_t i, std::size_t j){
+ auto dfs = even_step ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+
+ auto& rho = macros.at({{i,j}}).template get<"pressure">();
+ auto& vel = macros.at({{i,j}}).template get<"velocity">();
+ compute_rho_u<sch::T,sch::D2Q9>(dfs,rho,vel);
+ }, lattice);
+
+ std::string vtk_f_name{"tmp/cavity_2d_"};
+ vtk_f_name += std::to_string(file_no) + ".vtk";
+ write_vtk_file(vtk_f_name, macros);
+
+ ++file_no;
+ }
+
+ lbm_step(lattice, even_step, step);
+
+ even_step = not even_step;
+ }
+
+ /**
+ * Flush cout
+ */
+ std::cout<<"\n\n";
+ std::cout.flush();
+ return 0;
+}