1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
import numpy
import time
import matplotlib
import matplotlib.pyplot as plt
matplotlib.use('AGG')
from lbm import Lattice, Geometry
import symbolic.D2Q9 as D2Q9
def MLUPS(cells, steps, time):
return cells * steps / time * 1e-6
def generate_moment_plots(lattice, moments):
for i, m in enumerate(moments):
print("Generating plot %d of %d." % (i+1, len(moments)))
velocity = numpy.ndarray(shape=tuple(reversed(lattice.geometry.inner_span())))
for x, y in lattice.geometry.inner_cells():
velocity[y-1,x-1] = numpy.sqrt(m[1,lattice.idx(x,y)]**2 + m[2,lattice.idx(x,y)]**2)
plt.figure(figsize=(10, 10))
plt.imshow(velocity, origin='lower', cmap=plt.get_cmap('seismic'))
plt.savefig("result/implosion_%02d.png" % i, bbox_inches='tight', pad_inches=0)
def box(geometry, x, y):
if x == 1 or y == 1 or x == geometry.size_x-2 or y == geometry.size_y-2:
return 2
else:
return 1
pop_eq = """
if ( sqrt(pow(get_global_id(0) - ${geometry.size_x//2}.f, 2.f)
+ pow(get_global_id(1) - ${geometry.size_y//2}.f, 2.f)) < ${geometry.size_x//10} ) {
% for i, w_i in enumerate(descriptor.w):
preshifted_f_next[${i*geometry.volume}] = 1./24.f;
preshifted_f_prev[${i*geometry.volume}] = 1./24.f;
% endfor
} else {
% for i, w_i in enumerate(descriptor.w):
preshifted_f_next[${i*geometry.volume}] = ${w_i}.f;
preshifted_f_prev[${i*geometry.volume}] = ${w_i}.f;
% endfor
}"""
boundary = """
if ( m == 2 ) {
u_0 = 0.0;
u_1 = 0.0;
}
"""
nUpdates = 2000
nStat = 100
moments = []
print("Initializing simulation...\n")
lattice = Lattice(
descriptor = D2Q9,
geometry = Geometry(1024, 1024),
moments = D2Q9.moments(optimize = False),
collide = D2Q9.bgk(tau = 0.8),
pop_eq_src = pop_eq,
boundary_src = boundary)
lattice.setup_geometry(box)
print("Starting simulation using %d cells...\n" % lattice.geometry.volume)
lastStat = time.time()
for i in range(1,nUpdates+1):
lattice.evolve()
if i % nStat == 0:
lattice.sync()
print("i = %4d; %3.0f MLUPS" % (i, MLUPS(lattice.geometry.volume, nStat, time.time() - lastStat)))
moments.append(lattice.get_moments())
lastStat = time.time()
print("\nConcluded simulation.\n")
generate_moment_plots(lattice, moments)
|
