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#include <cstdint>
#include <memory>
#include <vector>
#include <chrono>
#include <iostream>
#include <fstream>
#include "kernel.h"
void collect_moments_to_vtk(const std::string& path, ${float_type}** f) {
std::ofstream fout;
fout.open(path.c_str());
fout << "# vtk DataFile Version 3.0\n";
fout << "lbm_output\n";
fout << "ASCII\n";
fout << "DATASET RECTILINEAR_GRID\n";
% if descriptor.d == 2:
fout << "DIMENSIONS " << ${geometry.size_x-2} << " " << ${geometry.size_y-2} << " 1" << "\n";
% else:
fout << "DIMENSIONS " << ${geometry.size_x-2} << " " << ${geometry.size_y-2} << " " << ${geometry.size_z-2} << "\n";
% endif
fout << "X_COORDINATES " << ${geometry.size_x-2} << " float\n";
for( std::size_t x = 1; x < ${geometry.size_x-1}; ++x ) {
fout << x << " ";
}
fout << "\nY_COORDINATES " << ${geometry.size_y-2} << " float\n";
for( std::size_t y = 1; y < ${geometry.size_y-1}; ++y ) {
fout << y << " ";
}
% if descriptor.d == 2:
fout << "\nZ_COORDINATES " << 1 << " float\n";
fout << 0 << "\n";
fout << "POINT_DATA " << ${(geometry.size_x-2) * (geometry.size_y-2)} << "\n";
% else:
fout << "\nZ_COORDINATES " << ${geometry.size_z-2} << " float\n";
for( std::size_t z = 1; z < ${geometry.size_z-1}; ++z ) {
fout << z << " ";
}
fout << "\nPOINT_DATA " << ${(geometry.size_x-2) * (geometry.size_y-2) * (geometry.size_z-2)} << "\n";
% endif
${float_type} rho;
${float_type} u[${descriptor.d}];
fout << "VECTORS velocity float\n";
% if descriptor.d == 2:
for ( std::size_t y = 1; y < ${geometry.size_y-1}; ++y ) {
for ( std::size_t x = 1; x < ${geometry.size_x-1}; ++x ) {
collect_moments(f, x*${geometry.size_y}+y, rho, u);
fout << u[0] << " " << u[1] << " 0\n";
}
}
% else:
for ( std::size_t z = 1; z < ${geometry.size_z-1}; ++z ) {
for ( std::size_t y = 1; y < ${geometry.size_y-1}; ++y ) {
for ( std::size_t x = 1; x < ${geometry.size_x-1}; ++x ) {
collect_moments(f, x*${geometry.size_y*geometry.size_z}+y*${geometry.size_z}+z, rho, u);
fout << u[0] << " " << u[1] << " " << u[2] << "\n";
}
}
}
% endif
fout << "SCALARS density float 1\n";
fout << "LOOKUP_TABLE default\n";
% if descriptor.d == 2:
for ( std::size_t y = 1; y < ${geometry.size_y-1}; ++y ) {
for ( std::size_t x = 1; x < ${geometry.size_x-1}; ++x ) {
collect_moments(f, x*${geometry.size_y}+y, rho, u);
fout << rho << "\n";
}
}
% else:
for ( std::size_t z = 1; z < ${geometry.size_z-1}; ++z ) {
for ( std::size_t y = 1; y < ${geometry.size_y-1}; ++y ) {
for ( std::size_t x = 1; x < ${geometry.size_x-1}; ++x ) {
collect_moments(f, x*${geometry.size_y*geometry.size_z}+y*${geometry.size_z}+z, rho, u);
fout << rho << "\n";
}
}
}
% endif
fout.close();
}
void simulate(std::size_t nStep)
{
<%
padding = (max(geometry.size_x,geometry.size_y,geometry.size_z)+1)**(descriptor.d-1)
%>
auto f_aa = std::make_unique<${float_type}[]>(${(geometry.volume+2*padding)*descriptor.q});
${float_type}* f[${descriptor.q}];
% for i, c_i in enumerate(descriptor.c):
f[${i}] = f_aa.get() + ${padding + layout.pop_offset(i, 2*padding)};
% endfor
std::vector<std::size_t> ghost;
std::vector<std::size_t> bulk;
std::vector<std::size_t> lid_bc;
std::vector<std::size_t> box_bc;
for (int iX = 0; iX < ${geometry.size_x}; ++iX) {
for (int iY = 0; iY < ${geometry.size_y}; ++iY) {
% if descriptor.d == 2:
const std::size_t iCell = iX*${geometry.size_y} + iY;
if (iX == 0 || iY == 0 || iX == ${geometry.size_x-1} || iY == ${geometry.size_y-1}) {
ghost.emplace_back(iCell);
} else if (iY == ${geometry.size_y-2}) {
lid_bc.emplace_back(iCell);
} else if (iX == 1 || iX == ${geometry.size_x-2} || iY == 1) {
box_bc.emplace_back(iCell);
} else {
bulk.emplace_back(iCell);
}
% elif descriptor.d == 3:
for (int iZ = 0; iZ < ${geometry.size_z}; ++iZ) {
const std::size_t iCell = iX*${geometry.size_y*geometry.size_z} + iY*${geometry.size_z} + iZ;
if ( iX == 0 || iY == 0 || iZ == 0
|| iX == ${geometry.size_x-1}
|| iY == ${geometry.size_y-1}
|| iZ == ${geometry.size_z-1}) {
ghost.emplace_back(iCell);
} else if (iZ == ${geometry.size_z-2}) {
lid_bc.emplace_back(iCell);
} else if ( iX == 1 || iX == ${geometry.size_x-2}
|| iY == 1 || iY == ${geometry.size_y-2}
|| iZ == 1) {
box_bc.emplace_back(iCell);
} else {
bulk.emplace_back(iCell);
}
}
% endif
}
}
std::cout << "#ghost : " << ghost.size() << std::endl;
std::cout << "#bulk : " << bulk.size() << std::endl;
std::cout << "#lid : " << lid_bc.size() << std::endl;
std::cout << "#wall : " << box_bc.size() << std::endl;
std::cout << std::endl;
#pragma omp parallel for
for (std::size_t iCell = 0; iCell < ${geometry.volume}; ++iCell) {
equilibrilize(f, iCell);
}
auto start = std::chrono::high_resolution_clock::now();
for (std::size_t iStep = 1; iStep <= nStep; ++iStep) {
#pragma omp parallel for
for (std::size_t i = 0; i < ghost.size(); ++i) {
equilibrilize(f, ghost[i]);
}
#pragma omp parallel for
for (std::size_t i = 0; i < bulk.size(); ++i) {
collide_and_stream(f, bulk[i]);
}
${float_type} u[${descriptor.d}] { 0. };
#pragma omp parallel for
for (std::size_t i = 0; i < box_bc.size(); ++i) {
velocity_momenta_boundary(f, box_bc[i], u);
}
u[0] = 0.05;
#pragma omp parallel for
for (std::size_t i = 0; i < lid_bc.size(); ++i) {
velocity_momenta_boundary(f, lid_bc[i], u);
}
if (iStep % 1000 == 0) {
auto duration = std::chrono::duration_cast<std::chrono::duration<double>>(
std::chrono::high_resolution_clock::now() - start);
std::cout << "iStep = " << iStep << "; ~" << 1000*${geometry.volume}/(1e6*duration.count()) << " MLUPS" << std::endl;
collect_moments_to_vtk("result/ldc_" + std::to_string(iStep) + ".vtk", f);
start = std::chrono::high_resolution_clock::now();
}
update_sss_control_structure(f);
}
}
int main() {
simulate(20000);
}
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