mirror of
https://github.com/smyalygames/FiniteVolumeGPU.git
synced 2025-05-18 22:44:12 +02:00
160 lines
5.3 KiB
Python
160 lines
5.3 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
This python module implements the 2nd order HLL flux
|
|
|
|
Copyright (C) 2016 SINTEF ICT
|
|
|
|
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/>.
|
|
"""
|
|
|
|
#Import packages we need
|
|
import numpy as np
|
|
|
|
import pycuda.compiler as cuda_compiler
|
|
import pycuda.gpuarray
|
|
import pycuda.driver as cuda
|
|
|
|
from SWESimulators import Common
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
"""
|
|
Class that solves the SW equations using the Forward-Backward linear scheme
|
|
"""
|
|
class HLL2:
|
|
|
|
"""
|
|
Initialization routine
|
|
h0: Water depth incl ghost cells, (nx+1)*(ny+1) cells
|
|
hu0: Initial momentum along x-axis incl ghost cells, (nx+1)*(ny+1) cells
|
|
hv0: Initial momentum along y-axis incl ghost cells, (nx+1)*(ny+1) cells
|
|
nx: Number of cells along x-axis
|
|
ny: Number of cells along y-axis
|
|
dx: Grid cell spacing along x-axis (20 000 m)
|
|
dy: Grid cell spacing along y-axis (20 000 m)
|
|
dt: Size of each timestep (90 s)
|
|
g: Gravitational accelleration (9.81 m/s^2)
|
|
"""
|
|
def __init__(self, \
|
|
context, \
|
|
h0, hu0, hv0, \
|
|
nx, ny, \
|
|
dx, dy, dt, \
|
|
g, \
|
|
theta=1.8, \
|
|
block_width=16, block_height=16):
|
|
#Create a CUDA stream
|
|
self.stream = cuda.Stream()
|
|
|
|
#Get kernels
|
|
self.hll2_module = context.get_kernel("HLL2_kernel.cu", block_width, block_height)
|
|
self.hll2_kernel = self.hll2_module.get_function("HLL2Kernel")
|
|
self.hll2_kernel.prepare("iifffffiPiPiPiPiPiPi")
|
|
|
|
#Create data by uploading to device
|
|
ghost_cells_x = 2
|
|
ghost_cells_y = 2
|
|
self.data = Common.SWEDataArakawaA(self.stream, \
|
|
nx, ny, \
|
|
ghost_cells_x, ghost_cells_y, \
|
|
h0, hu0, hv0)
|
|
|
|
#Save input parameters
|
|
#Notice that we need to specify them in the correct dataformat for the
|
|
#OpenCL kernel
|
|
self.nx = np.int32(nx)
|
|
self.ny = np.int32(ny)
|
|
self.dx = np.float32(dx)
|
|
self.dy = np.float32(dy)
|
|
self.dt = np.float32(dt)
|
|
self.g = np.float32(g)
|
|
self.theta = np.float32(theta)
|
|
|
|
#Initialize time
|
|
self.t = np.float32(0.0)
|
|
|
|
#Compute kernel launch parameters
|
|
self.local_size = (block_width, block_height, 1)
|
|
self.global_size = ( \
|
|
int(np.ceil(self.nx / float(self.local_size[0]))), \
|
|
int(np.ceil(self.ny / float(self.local_size[1]))) \
|
|
)
|
|
|
|
|
|
def __str__(self):
|
|
return "Harten-Lax-van Leer (2nd order)"
|
|
|
|
|
|
"""
|
|
Function which steps n timesteps
|
|
"""
|
|
def step(self, t_end=0.0):
|
|
n = int(t_end / (2.0*self.dt) + 1)
|
|
|
|
for i in range(0, n):
|
|
#Dimensional splitting: second order accurate for every other timestep,
|
|
#thus run two timesteps in a go
|
|
|
|
local_dt = np.float32(0.5*min(2*self.dt, t_end-2*i*self.dt))
|
|
if (local_dt <= 0.0):
|
|
break
|
|
|
|
#Along X, then Y
|
|
self.hll2_kernel.prepared_async_call(self.global_size, self.local_size, self.stream, \
|
|
self.nx, self.ny, \
|
|
self.dx, self.dy, local_dt, \
|
|
self.g, \
|
|
self.theta, \
|
|
np.int32(0), \
|
|
self.data.h0.data.gpudata, self.data.h0.pitch, \
|
|
self.data.hu0.data.gpudata, self.data.hu0.pitch, \
|
|
self.data.hv0.data.gpudata, self.data.hv0.pitch, \
|
|
self.data.h1.data.gpudata, self.data.h1.pitch, \
|
|
self.data.hu1.data.gpudata, self.data.hu1.pitch, \
|
|
self.data.hv1.data.gpudata, self.data.hv1.pitch)
|
|
self.data.swap()
|
|
|
|
#Along Y, then X
|
|
self.hll2_kernel.prepared_async_call(self.global_size, self.local_size, self.stream, \
|
|
self.nx, self.ny, \
|
|
self.dx, self.dy, local_dt, \
|
|
self.g, \
|
|
self.theta, \
|
|
np.int32(1), \
|
|
self.data.h0.data.gpudata, self.data.h0.pitch, \
|
|
self.data.hu0.data.gpudata, self.data.hu0.pitch, \
|
|
self.data.hv0.data.gpudata, self.data.hv0.pitch, \
|
|
self.data.h1.data.gpudata, self.data.h1.pitch, \
|
|
self.data.hu1.data.gpudata, self.data.hu1.pitch, \
|
|
self.data.hv1.data.gpudata, self.data.hv1.pitch)
|
|
self.data.swap()
|
|
|
|
self.t += local_dt
|
|
|
|
|
|
return self.t
|
|
|
|
|
|
|
|
def download(self):
|
|
return self.data.download(self.stream)
|
|
|