mirror of
https://github.com/smyalygames/FiniteVolumeGPU.git
synced 2025-11-27 23:29:49 +01:00
247 lines
10 KiB
Plaintext
247 lines
10 KiB
Plaintext
/*
|
|
This kernel implements the Central Upwind flux function to
|
|
solve the Euler equations
|
|
|
|
Copyright (C) 2018 SINTEF Digital
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
#include "common.h"
|
|
#include "EulerCommon.h"
|
|
#include "limiters.h"
|
|
|
|
|
|
__device__
|
|
void computeFluxF(float Q[4][BLOCK_HEIGHT + 4][BLOCK_WIDTH + 4],
|
|
float Qx[4][BLOCK_HEIGHT + 4][BLOCK_WIDTH + 4],
|
|
float F[4][BLOCK_HEIGHT + 4][BLOCK_WIDTH + 4],
|
|
const float gamma_, const float dx_, const float dt_) {
|
|
for (unsigned int j = threadIdx.y; j < BLOCK_HEIGHT + 4; j += BLOCK_HEIGHT) {
|
|
for (unsigned int i = threadIdx.x + 1; i < BLOCK_WIDTH + 2; i += BLOCK_WIDTH) {
|
|
// Reconstruct point values of Q at the left and right hand side
|
|
// of the cell for both the left (i) and right (i+1) cell
|
|
const float4 Q_rl = make_float4(Q[0][j][i + 1] - 0.5f * Qx[0][j][i + 1],
|
|
Q[1][j][i + 1] - 0.5f * Qx[1][j][i + 1],
|
|
Q[2][j][i + 1] - 0.5f * Qx[2][j][i + 1],
|
|
Q[3][j][i + 1] - 0.5f * Qx[3][j][i + 1]);
|
|
const float4 Q_rr = make_float4(Q[0][j][i + 1] + 0.5f * Qx[0][j][i + 1],
|
|
Q[1][j][i + 1] + 0.5f * Qx[1][j][i + 1],
|
|
Q[2][j][i + 1] + 0.5f * Qx[2][j][i + 1],
|
|
Q[3][j][i + 1] + 0.5f * Qx[3][j][i + 1]);
|
|
|
|
const float4 Q_ll = make_float4(Q[0][j][i] - 0.5f * Qx[0][j][i],
|
|
Q[1][j][i] - 0.5f * Qx[1][j][i],
|
|
Q[2][j][i] - 0.5f * Qx[2][j][i],
|
|
Q[3][j][i] - 0.5f * Qx[3][j][i]);
|
|
const float4 Q_lr = make_float4(Q[0][j][i] + 0.5f * Qx[0][j][i],
|
|
Q[1][j][i] + 0.5f * Qx[1][j][i],
|
|
Q[2][j][i] + 0.5f * Qx[2][j][i],
|
|
Q[3][j][i] + 0.5f * Qx[3][j][i]);
|
|
|
|
|
|
// Evolve half a timestep (predictor step)
|
|
const float4 Q_r_bar = Q_rl + dt_ / (2.0f * dx_) * (F_func(Q_rl, gamma_) - F_func(Q_rr, gamma_));
|
|
const float4 Q_l_bar = Q_lr + dt_ / (2.0f * dx_) * (F_func(Q_ll, gamma_) - F_func(Q_lr, gamma_));
|
|
|
|
// Compute flux based on prediction
|
|
// const float4 flux = CentralUpwindFlux(Q_l_bar, Q_r_bar, gamma_);
|
|
const auto [x, y, z, w] = HLL_flux(Q_l_bar, Q_r_bar, gamma_);
|
|
|
|
// Write to shared memory
|
|
F[0][j][i] = x;
|
|
F[1][j][i] = y;
|
|
F[2][j][i] = z;
|
|
F[3][j][i] = w;
|
|
}
|
|
}
|
|
}
|
|
|
|
__device__
|
|
void computeFluxG(float Q[4][BLOCK_HEIGHT + 4][BLOCK_WIDTH + 4],
|
|
float Qy[4][BLOCK_HEIGHT + 4][BLOCK_WIDTH + 4],
|
|
float G[4][BLOCK_HEIGHT + 4][BLOCK_WIDTH + 4],
|
|
const float gamma_, const float dy_, const float dt_) {
|
|
for (unsigned int j = threadIdx.y + 1; j < BLOCK_HEIGHT + 2; j += BLOCK_HEIGHT) {
|
|
for (unsigned int i = threadIdx.x; i < BLOCK_WIDTH + 4; i += BLOCK_WIDTH) {
|
|
// Reconstruct point values of Q at the left and right hand side
|
|
// of the cell for both the left (i) and right (i+1) cell
|
|
// Note that hu and hv are swapped ("transposing" the domain)!
|
|
const float4 Q_rl = make_float4(Q[0][j + 1][i] - 0.5f * Qy[0][j + 1][i],
|
|
Q[2][j + 1][i] - 0.5f * Qy[2][j + 1][i],
|
|
Q[1][j + 1][i] - 0.5f * Qy[1][j + 1][i],
|
|
Q[3][j + 1][i] - 0.5f * Qy[3][j + 1][i]);
|
|
const float4 Q_rr = make_float4(Q[0][j + 1][i] + 0.5f * Qy[0][j + 1][i],
|
|
Q[2][j + 1][i] + 0.5f * Qy[2][j + 1][i],
|
|
Q[1][j + 1][i] + 0.5f * Qy[1][j + 1][i],
|
|
Q[3][j + 1][i] + 0.5f * Qy[3][j + 1][i]);
|
|
|
|
const float4 Q_ll = make_float4(Q[0][j][i] - 0.5f * Qy[0][j][i],
|
|
Q[2][j][i] - 0.5f * Qy[2][j][i],
|
|
Q[1][j][i] - 0.5f * Qy[1][j][i],
|
|
Q[3][j][i] - 0.5f * Qy[3][j][i]);
|
|
const float4 Q_lr = make_float4(Q[0][j][i] + 0.5f * Qy[0][j][i],
|
|
Q[2][j][i] + 0.5f * Qy[2][j][i],
|
|
Q[1][j][i] + 0.5f * Qy[1][j][i],
|
|
Q[3][j][i] + 0.5f * Qy[3][j][i]);
|
|
|
|
// Evolve half a timestep (predictor step)
|
|
const float4 Q_r_bar = Q_rl + dt_ / (2.0f * dy_) * (F_func(Q_rl, gamma_) - F_func(Q_rr, gamma_));
|
|
const float4 Q_l_bar = Q_lr + dt_ / (2.0f * dy_) * (F_func(Q_ll, gamma_) - F_func(Q_lr, gamma_));
|
|
|
|
// Compute flux based on prediction
|
|
const auto [x, y, z, w] = CentralUpwindFlux(Q_l_bar, Q_r_bar, gamma_);
|
|
// const float4 flux = HLL_flux(Q_l_bar, Q_r_bar, gamma_);
|
|
|
|
// Write to shared memory
|
|
// Note that we here swap hu and hv back to the original
|
|
G[0][j][i] = x;
|
|
G[1][j][i] = z;
|
|
G[2][j][i] = y;
|
|
G[3][j][i] = w;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* This unsplit kernel computes the 2D numerical scheme with a TVD RK2 time integration scheme
|
|
*/
|
|
extern "C" {
|
|
__global__ void KP07DimsplitKernel(
|
|
const int nx_, const int ny_,
|
|
const float dx_, const float dy_, const float dt_,
|
|
const float g_,
|
|
const float gamma_,
|
|
|
|
const float theta_,
|
|
|
|
const int step_,
|
|
const int boundary_conditions_,
|
|
|
|
// Input h^n
|
|
float *rho0_ptr_, const int rho0_pitch_,
|
|
float *rho_u0_ptr_, const int rho_u0_pitch_,
|
|
float *rho_v0_ptr_, const int rho_v0_pitch_,
|
|
float *E0_ptr_, const int E0_pitch_,
|
|
|
|
// Output h^{n+1}
|
|
float *rho1_ptr_, const int rho1_pitch_,
|
|
float *rho_u1_ptr_, const int rho_u1_pitch_,
|
|
float *rho_v1_ptr_, const int rho_v1_pitch_,
|
|
float *E1_ptr_, const int E1_pitch_,
|
|
|
|
// Output CFL
|
|
float *cfl_,
|
|
|
|
// Subarea of internal domain to compute
|
|
const int x0 = 0, const int y0 = 0,
|
|
int x1 = 0, int y1 = 0) {
|
|
if (x1 == 0)
|
|
x1 = nx_;
|
|
|
|
if (y1 == 0)
|
|
y1 = ny_;
|
|
|
|
constexpr unsigned int w = BLOCK_WIDTH;
|
|
constexpr unsigned int h = BLOCK_HEIGHT;
|
|
constexpr unsigned int gc_x = 2;
|
|
constexpr unsigned int gc_y = 2;
|
|
constexpr unsigned int vars = 4;
|
|
|
|
// Shared memory variables
|
|
__shared__ float Q[4][h + 2 * gc_y][w + 2 * gc_x];
|
|
__shared__ float Qx[4][h + 2 * gc_y][w + 2 * gc_x];
|
|
__shared__ float F[4][h + 2 * gc_y][w + 2 * gc_x];
|
|
|
|
// Read into shared memory
|
|
readBlock<w, h, gc_x, gc_y, 1, 1>(rho0_ptr_, rho0_pitch_, Q[0], nx_, ny_, boundary_conditions_, x0, y0, x1, y1);
|
|
readBlock<w, h, gc_x, gc_y, -1, 1>(rho_u0_ptr_, rho_u0_pitch_, Q[1], nx_, ny_, boundary_conditions_, x0, y0, x1,
|
|
y1);
|
|
readBlock<w, h, gc_x, gc_y, 1, -1>(rho_v0_ptr_, rho_v0_pitch_, Q[2], nx_, ny_, boundary_conditions_, x0, y0, x1,
|
|
y1);
|
|
readBlock<w, h, gc_x, gc_y, 1, 1>(E0_ptr_, E0_pitch_, Q[3], nx_, ny_, boundary_conditions_, x0, y0, x1, y1);
|
|
|
|
// Step 0 => evolve x first, then y
|
|
if (step_ == 0) {
|
|
// Compute fluxes along the x-axis and evolve
|
|
minmodSlopeX<w, h, gc_x, gc_y, vars>(Q, Qx, theta_);
|
|
__syncthreads();
|
|
computeFluxF(Q, Qx, F, gamma_, dx_, dt_);
|
|
__syncthreads();
|
|
evolveF<w, h, gc_x, gc_y, vars>(Q, F, dx_, dt_);
|
|
__syncthreads();
|
|
|
|
// Compute fluxes along the y-axis and evolve
|
|
minmodSlopeY<w, h, gc_x, gc_y, vars>(Q, Qx, theta_);
|
|
__syncthreads();
|
|
computeFluxG(Q, Qx, F, gamma_, dy_, dt_);
|
|
__syncthreads();
|
|
evolveG<w, h, gc_x, gc_y, vars>(Q, F, dy_, dt_);
|
|
__syncthreads();
|
|
|
|
// Gravity source term
|
|
if (g_ > 0.0f) {
|
|
const unsigned int i = threadIdx.x + gc_x;
|
|
const unsigned int j = threadIdx.y + gc_y;
|
|
const float rho_v = Q[2][j][i];
|
|
Q[2][j][i] -= g_ * Q[0][j][i] * dt_;
|
|
Q[3][j][i] -= g_ * rho_v * dt_;
|
|
__syncthreads();
|
|
}
|
|
}
|
|
// Step 1 => evolve y first, then x
|
|
else {
|
|
// Compute fluxes along the y-axis and evolve
|
|
minmodSlopeY<w, h, gc_x, gc_y, vars>(Q, Qx, theta_);
|
|
__syncthreads();
|
|
computeFluxG(Q, Qx, F, gamma_, dy_, dt_);
|
|
__syncthreads();
|
|
evolveG<w, h, gc_x, gc_y, vars>(Q, F, dy_, dt_);
|
|
__syncthreads();
|
|
|
|
// Compute fluxes along the x-axis and evolve
|
|
minmodSlopeX<w, h, gc_x, gc_y, vars>(Q, Qx, theta_);
|
|
__syncthreads();
|
|
computeFluxF(Q, Qx, F, gamma_, dx_, dt_);
|
|
__syncthreads();
|
|
evolveF<w, h, gc_x, gc_y, vars>(Q, F, dx_, dt_);
|
|
__syncthreads();
|
|
|
|
// Gravity source term
|
|
if (g_ > 0.0f) {
|
|
const unsigned int i = threadIdx.x + gc_x;
|
|
const unsigned int j = threadIdx.y + gc_y;
|
|
const float rho_v = Q[2][j][i];
|
|
Q[2][j][i] -= g_ * Q[0][j][i] * dt_;
|
|
Q[3][j][i] -= g_ * rho_v * dt_;
|
|
__syncthreads();
|
|
}
|
|
}
|
|
|
|
|
|
// Write to main memory for all internal cells
|
|
writeBlock<w, h, gc_x, gc_y>(rho1_ptr_, rho1_pitch_, Q[0], nx_, ny_, 0, 1, x0, y0, x1, y1);
|
|
writeBlock<w, h, gc_x, gc_y>(rho_u1_ptr_, rho_u1_pitch_, Q[1], nx_, ny_, 0, 1, x0, y0, x1, y1);
|
|
writeBlock<w, h, gc_x, gc_y>(rho_v1_ptr_, rho_v1_pitch_, Q[2], nx_, ny_, 0, 1, x0, y0, x1, y1);
|
|
writeBlock<w, h, gc_x, gc_y>(E1_ptr_, E1_pitch_, Q[3], nx_, ny_, 0, 1, x0, y0, x1, y1);
|
|
|
|
// Compute the CFL for this block
|
|
if (cfl_ != nullptr) {
|
|
writeCfl<w, h, gc_x, gc_y, vars>(Q, F[0], nx_, ny_, dx_, dy_, gamma_, cfl_);
|
|
}
|
|
}
|
|
} // extern "C"
|