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#include <cstdint>
#include <memory>
#include <vector>
#include <chrono>
#include <iostream>
#include <fstream>
#include "kernel.h"
void write_moments_to_vtk(const std::string& path, ${float_type}* u) {
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
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 < ${geometry.size_x-1}; ++x ) {
const std::size_t gid = x*${geometry.size_y}+y;
fout << u[gid*${descriptor.d}+0] << " " << u[gid*${descriptor.d}+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 < ${geometry.size_x-1}; ++x ) {
const std::size_t gid = x*${geometry.size_y*geometry.size_z}+y*${geometry.size_z}+z;
fout << u[gid*${descriptor.d}+0] << " " << u[gid*${descriptor.d}+1] << " " << u[gid*${descriptor.d}+2] << "\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)
%>
${float_type}* f_aa;
cudaMalloc(&f_aa, ${(geometry.volume+2*padding)*descriptor.q}*sizeof(${float_type}));
${float_type}** f;
cudaMalloc(&f, ${descriptor.q}*sizeof(${float_type}*));
${float_type}* device_moments_rho;
cudaMalloc(&device_moments_rho, ${geometry.volume} * sizeof(${float_type}));
${float_type}* device_moments_u;
cudaMalloc(&device_moments_u, ${geometry.volume*descriptor.d} * sizeof(${float_type}));
std::vector<${float_type}> moments_u(${geometry.volume*descriptor.d});
init_sss_control_structure<<<1,1>>>(f_aa, f);
cudaDeviceSynchronize();
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;
std::size_t* device_ghost_cells;
std::size_t* device_bulk_cells;
std::size_t* device_lid_bc_cells;
std::size_t* device_box_bc_cells;
cudaMalloc(&device_ghost_cells, ghost.size() * sizeof(std::size_t));
cudaMalloc(&device_bulk_cells, bulk.size() * sizeof(std::size_t));
cudaMalloc(&device_lid_bc_cells, lid_bc.size() * sizeof(std::size_t));
cudaMalloc(&device_box_bc_cells, box_bc.size() * sizeof(std::size_t));
cudaMemcpy(device_ghost_cells, ghost.data(), ghost.size() * sizeof(std::size_t), cudaMemcpyHostToDevice);
cudaMemcpy(device_bulk_cells, bulk.data(), bulk.size() * sizeof(std::size_t), cudaMemcpyHostToDevice);
cudaMemcpy(device_lid_bc_cells, lid_bc.data(), lid_bc.size()* sizeof(std::size_t), cudaMemcpyHostToDevice);
cudaMemcpy(device_box_bc_cells, box_bc.data(), box_bc.size()* sizeof(std::size_t), cudaMemcpyHostToDevice);
cudaDeviceSynchronize();
const std::size_t block_size = 32;
std::size_t block_count = 0;
block_count = (ghost.size() + block_size - 1) / block_size;
equilibrilize<<<block_count,block_size>>>(f, device_ghost_cells, ghost.size());
block_count = (bulk.size() + block_size - 1) / block_size;
equilibrilize<<<block_count,block_size>>>(f, device_bulk_cells, bulk.size());
block_count = (box_bc.size() + block_size - 1) / block_size;
equilibrilize<<<block_count,block_size>>>(f, device_box_bc_cells, box_bc.size());
block_count = (lid_bc.size() + block_size - 1) / block_size;
equilibrilize<<<block_count,block_size>>>(f, device_lid_bc_cells, lid_bc.size());
cudaDeviceSynchronize();
auto start = std::chrono::high_resolution_clock::now();
for (std::size_t iStep = 1; iStep <= nStep; ++iStep) {
block_count = (ghost.size() + block_size - 1) / block_size;
equilibrilize<<<block_count,block_size>>>(f, device_ghost_cells, ghost.size());
block_count = (bulk.size() + block_size - 1) / block_size;
collide_and_stream<<<block_count,block_size>>>(f, device_bulk_cells, bulk.size());
block_count = (box_bc.size() + block_size - 1) / block_size;
% if descriptor.d == 2:
velocity_momenta_boundary<<<block_count,block_size>>>(f, device_box_bc_cells, box_bc.size(), 0.0, 0.0);
% else:
velocity_momenta_boundary<<<block_count,block_size>>>(f, device_box_bc_cells, box_bc.size(), 0.0, 0.0, 0.0);
% endif
block_count = (lid_bc.size() + block_size - 1) / block_size;
% if descriptor.d == 2:
velocity_momenta_boundary<<<block_count,block_size>>>(f, device_lid_bc_cells, lid_bc.size(), 0.05, 0.0);
% else:
velocity_momenta_boundary<<<block_count,block_size>>>(f, device_lid_bc_cells, lid_bc.size(), 0.05, 0.0, 0.0);
% endif
cudaDeviceSynchronize();
update_sss_control_structure<<<1,1>>>(f);
cudaDeviceSynchronize();
if (iStep % 1000 == 0) {
auto duration = std::chrono::duration_cast<std::chrono::duration<float>>(
std::chrono::high_resolution_clock::now() - start);
std::cout << "iStep = " << iStep << "; ~" << 1000*${geometry.volume}/(1e6*duration.count()) << " MLUPS" << std::endl;
block_count = (bulk.size() + block_size - 1) / block_size;
collect_moments<<<block_count,block_size>>>(f, device_bulk_cells, bulk.size(), device_moments_rho, device_moments_u);
cudaMemcpy(moments_u.data(), device_moments_u, ${geometry.volume*descriptor.d}*sizeof(${float_type}), cudaMemcpyDeviceToHost);
write_moments_to_vtk("result/ldc_" + std::to_string(iStep) + ".vtk", moments_u.data());
start = std::chrono::high_resolution_clock::now();
}
}
cudaFree(device_ghost_cells);
cudaFree(device_bulk_cells);
cudaFree(device_lid_bc_cells);
cudaFree(device_box_bc_cells);
cudaFree(device_moments_rho);
cudaFree(device_moments_u);
cudaFree(f);
cudaFree(f_aa);
}
int main() {
simulate(20000);
}
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