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
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
\subsection{\texttt{hopper\_flow.py}}\label{code:hopper_flow}
\begin{verbatim}
#hopper_flow.py: A hopper flow simulation with mesh walls using
# ESyS-Particle
# Author: W. Hancock
# Date: 10 July 2009
# Organisation: ESSCC, University of Queensland
# (C) All rights reserved, 2009.
#
#
#import the appropriate ESyS-Particle modules:
from esys.lsm import *
from esys.lsm.util import *
from esys.lsm.geometry import *
#instantiate a simulation object and
#initialise the neighbour search algorithm:
sim = LsmMpi (numWorkerProcesses = 1, mpiDimList = [1,1,1])
sim.initNeighbourSearch (
particleType = "NRotSphere",
gridSpacing = 2.5000,
verletDist = 0.1000
)
#specify the number of timesteps and the timestep increment:
sim.setNumTimeSteps (100000)
sim.setTimeStepSize (1.0000e-04)
#specify the spatial domain for the simulation:
domain = BoundingBox(Vec3(-20,-20,-20), Vec3(20,20,20))
sim.setSpatialDomain(domain)
#construct a block of particles with radii in range [0.2,0.5]:
geoRandomBlock = RandomBoxPacker (
minRadius = 0.2000,
maxRadius = 0.5000,
cubicPackRadius = 2.2000,
maxInsertFails = 1000,
bBox = BoundingBox(
Vec3(-5.0000, 0.0000,-5.0000),
Vec3(5.0000, 10.0000, 5.0000)
),
circDimList = [False, False, False],
tolerance = 1.0000e-05
)
geoRandomBlock.generate()
geoRandomBlock_particles = geoRandomBlock.getSimpleSphereCollection()
#add particles to simulation one at a time,
#tagging those in layers of 2m
for pp in geoRandomBlock_particles:
centre = pp.getPosn()
Y = centre[1]
if (int(Y%4) < 2):
pp.setTag(1) # layer 1
else:
pp.setTag(2) # layer 2
sim.createParticle(pp) # add the particle to the simulation object
#add a wall as a floor for the model:
sim.readMesh(
fileName = "floorMesh.msh",
meshName = "floor_mesh_wall"
)
#add a left side wall to the model:
sim.createWall (
name = "left_wall",
posn = Vec3(-5.0000, 0.0000, 0.0000),
normal = Vec3(1.0000, 0.0000, 0.0000)
)
#add a right side wall to the model:
sim.createWall (
name = "right_wall",
posn = Vec3(5.0000, 0.0000, 0.0000),
normal = Vec3(-1.0000, 0.0000, 0.0000)
)
#add a back wall to the model:
sim.createWall (
name = "back_wall",
posn = Vec3(0.0000, 0.0000, -5.0000),
normal = Vec3(0.0000, 0.0000, 1.0000)
)
#add a front wall to the model:
sim.createWall (
name = "front_wall",
posn = Vec3(0.0000, 0.0000, 5.0000),
normal = Vec3(0.0000, 0.0000, -1.0000)
)
#specify that particles undergo frictional interactions:
sim.createInteractionGroup (
NRotFrictionPrms (
name = "friction",
normalK = 1000.0,
dynamicMu = 0.6,
shearK = 100.0,
scaling = True
)
)
#specify that particles undergo elastic repulsion
#with the floor mesh wall:
sim.createInteractionGroup (
NRotElasticTriMeshPrms (
name = "floorWall_repell",
meshName = "floor_mesh_wall",
normalK = 1.0000e+04
)
)
#specify that particles undergo elastic repulsion
#from the left side wall:
sim.createInteractionGroup (
NRotElasticWallPrms (
name = "lw_repell",
wallName = "left_wall",
normalK = 1.0000e+04
)
)
#specify that particles undergo elastic repulsion
#from the right side wall:
sim.createInteractionGroup (
NRotElasticWallPrms (
name = "rw_repell",
wallName = "right_wall",
normalK = 1.0000e+04
)
)
#specify that particles undergo elastic repulsion
#from the back wall:
sim.createInteractionGroup (
NRotElasticWallPrms (
name = "bw_repell",
wallName = "back_wall",
normalK = 1.0000e+04
)
)
#specify that particles undergo elastic repulsion
#from the front wall:
sim.createInteractionGroup (
NRotElasticWallPrms (
name = "fw_repell",
wallName = "front_wall",
normalK = 1.0000e+04
)
)
#specify the direction and magnitude of gravity:
sim.createInteractionGroup (
GravityPrms (
name = "gravity",
acceleration = Vec3(0.0000, -9.8100, 0.0000)
)
)
#add viscosity to damp particle oscillations:
sim.createInteractionGroup (
LinDampingPrms (
name = "viscosity",
viscosity = 0.1000,
maxIterations = 100
)
)
#add a CheckPointer to store simulation data:
sim.createCheckPointer (
CheckPointPrms (
fileNamePrefix = "flow_data",
beginTimeStep = 0,
endTimeStep = 100000,
timeStepIncr = 1000
)
)
#execute the simulation:
sim.run()
\end{verbatim}
|
