mirror of
https://github.com/smyalygames/FiniteVolumeGPU.git
synced 2025-05-17 22:14:14 +02:00
139 lines
5.1 KiB
Python
139 lines
5.1 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
This python module implements the Kurganov-Petrova numerical scheme
|
|
for the shallow water equations, described in
|
|
A. Kurganov & Guergana Petrova
|
|
A Second-Order Well-Balanced Positivity Preserving Central-Upwind
|
|
Scheme for the Saint-Venant System Communications in Mathematical
|
|
Sciences, 5 (2007), 133-160.
|
|
|
|
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
|
|
from GPUSimulators import Simulator, Common
|
|
from GPUSimulators.Simulator import BaseSimulator, BoundaryCondition
|
|
import numpy as np
|
|
|
|
from pycuda import gpuarray
|
|
|
|
|
|
|
|
|
|
"""
|
|
Class that solves the SW equations using the Forward-Backward linear scheme
|
|
"""
|
|
class KP07 (Simulator.BaseSimulator):
|
|
|
|
"""
|
|
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,
|
|
g,
|
|
theta=1.3,
|
|
cfl_scale=0.9,
|
|
order=2,
|
|
boundary_conditions=BoundaryCondition(),
|
|
block_width=16, block_height=16):
|
|
|
|
# Call super constructor
|
|
super().__init__(context,
|
|
nx, ny,
|
|
dx, dy,
|
|
cfl_scale,
|
|
order,
|
|
block_width, block_height);
|
|
self.g = np.float32(g)
|
|
self.theta = np.float32(theta)
|
|
self.order = np.int32(order)
|
|
self.boundary_conditions = boundary_conditions.asCodedInt()
|
|
|
|
#Get kernels
|
|
module = context.get_module("cuda/SWE2D_KP07.cu",
|
|
defines={
|
|
'BLOCK_WIDTH': self.block_size[0],
|
|
'BLOCK_HEIGHT': self.block_size[1]
|
|
},
|
|
compile_args={
|
|
'no_extern_c': True,
|
|
'options': ["--use_fast_math"],
|
|
},
|
|
jit_compile_args={})
|
|
self.kernel = module.get_function("KP07Kernel")
|
|
self.kernel.prepare("iifffffiiPiPiPiPiPiPiP")
|
|
|
|
#Create data by uploading to device
|
|
self.u0 = Common.ArakawaA2D(self.stream,
|
|
nx, ny,
|
|
2, 2,
|
|
[h0, hu0, hv0])
|
|
self.u1 = Common.ArakawaA2D(self.stream,
|
|
nx, ny,
|
|
2, 2,
|
|
[None, None, None])
|
|
self.cfl_data = gpuarray.GPUArray(self.grid_size, dtype=np.float32)
|
|
dt_x = np.min(self.dx / (np.abs(hu0/h0) + np.sqrt(g*h0)))
|
|
dt_y = np.min(self.dy / (np.abs(hv0/h0) + np.sqrt(g*h0)))
|
|
dt = min(dt_x, dt_y)
|
|
self.cfl_data.fill(dt, stream=self.stream)
|
|
|
|
|
|
def substep(self, dt, step_number):
|
|
self.substepRK(dt, step_number)
|
|
|
|
|
|
def substepRK(self, dt, substep):
|
|
self.kernel.prepared_async_call(self.grid_size, self.block_size, self.stream,
|
|
self.nx, self.ny,
|
|
self.dx, self.dy, dt,
|
|
self.g,
|
|
self.theta,
|
|
Simulator.stepOrderToCodedInt(step=substep, order=self.order),
|
|
self.boundary_conditions,
|
|
self.u0[0].data.gpudata, self.u0[0].data.strides[0],
|
|
self.u0[1].data.gpudata, self.u0[1].data.strides[0],
|
|
self.u0[2].data.gpudata, self.u0[2].data.strides[0],
|
|
self.u1[0].data.gpudata, self.u1[0].data.strides[0],
|
|
self.u1[1].data.gpudata, self.u1[1].data.strides[0],
|
|
self.u1[2].data.gpudata, self.u1[2].data.strides[0],
|
|
self.cfl_data.gpudata)
|
|
self.u0, self.u1 = self.u1, self.u0
|
|
|
|
|
|
def download(self):
|
|
return self.u0.download(self.stream)
|
|
|
|
def check(self):
|
|
self.u0.check()
|
|
self.u1.check()
|
|
|
|
def computeDt(self):
|
|
max_dt = gpuarray.min(self.cfl_data, stream=self.stream).get();
|
|
return max_dt*0.5**(self.order-1) |