| 1 |
|
| 2 |
######################################################## |
| 3 |
# |
| 4 |
# Copyright (c) 2009-2010 by University of Queensland |
| 5 |
# Earth Systems Science Computational Center (ESSCC) |
| 6 |
# http://www.uq.edu.au/esscc |
| 7 |
# |
| 8 |
# Primary Business: Queensland, Australia |
| 9 |
# Licensed under the Open Software License version 3.0 |
| 10 |
# http://www.opensource.org/licenses/osl-3.0.php |
| 11 |
# |
| 12 |
######################################################## |
| 13 |
|
| 14 |
__copyright__="""Copyright (c) 2009-2010 by University of Queensland |
| 15 |
Earth Systems Science Computational Center (ESSCC) |
| 16 |
http://www.uq.edu.au/esscc |
| 17 |
Primary Business: Queensland, Australia""" |
| 18 |
__license__="""Licensed under the Open Software License version 3.0 |
| 19 |
http://www.opensource.org/licenses/osl-3.0.php""" |
| 20 |
__url__="https://launchpad.net/escript-finley" |
| 21 |
|
| 22 |
############################################################FILE HEADER |
| 23 |
# example07a.py |
| 24 |
# Antony Hallam |
| 25 |
# Acoustic Wave Equation Simulation using displacement solution |
| 26 |
|
| 27 |
#######################################################EXTERNAL MODULES |
| 28 |
from esys.escript import * |
| 29 |
from esys.finley import Rectangle |
| 30 |
import sys |
| 31 |
import os |
| 32 |
# smoothing operator |
| 33 |
from esys.escript.pdetools import Projector, Locator |
| 34 |
from esys.escript.unitsSI import * |
| 35 |
import numpy as np |
| 36 |
import pylab as pl |
| 37 |
import matplotlib.cm as cm |
| 38 |
from esys.escript.linearPDEs import LinearPDE |
| 39 |
|
| 40 |
########################################################MPI WORLD CHECK |
| 41 |
if getMPISizeWorld() > 1: |
| 42 |
import sys |
| 43 |
print "This example will not run in an MPI world." |
| 44 |
sys.exit(0) |
| 45 |
|
| 46 |
#################################################ESTABLISHING VARIABLES |
| 47 |
# where to save output data |
| 48 |
savepath = "data/example07a" |
| 49 |
mkDir(savepath) |
| 50 |
#Geometric and material property related variables. |
| 51 |
mx = 1000. # model lenght |
| 52 |
my = 1000. # model width |
| 53 |
ndx = 400 # steps in x direction |
| 54 |
ndy = 400 # steps in y direction |
| 55 |
xstep=mx/ndx # calculate the size of delta x |
| 56 |
ystep=my/ndy # calculate the size of delta y |
| 57 |
|
| 58 |
c=380.0*m/sec # velocity of sound in air |
| 59 |
csq=c*c #square of c |
| 60 |
# Time related variables. |
| 61 |
tend=1.5 # end time |
| 62 |
h=0.001 # time step |
| 63 |
# data recording times |
| 64 |
rtime=0.0 # first time to record |
| 65 |
rtime_inc=tend/20.0 # time increment to record |
| 66 |
#Check to make sure number of time steps is not too large. |
| 67 |
print "Time step size= ",h, "Expected number of outputs= ",tend/h |
| 68 |
|
| 69 |
U0=0.005 # amplitude of point source |
| 70 |
# want a spherical source in the middle of area |
| 71 |
xc=[500,500] # with reference to mx,my this is the source location |
| 72 |
|
| 73 |
####################################################DOMAIN CONSTRUCTION |
| 74 |
mydomain=Rectangle(l0=mx,l1=my,n0=ndx, n1=ndy) # create the domain |
| 75 |
x=mydomain.getX() # get the node locations of the domain |
| 76 |
|
| 77 |
##########################################################ESTABLISH PDE |
| 78 |
mypde=LinearPDE(mydomain) # create pde |
| 79 |
mypde.setSymmetryOn() # turn symmetry on |
| 80 |
mypde.setValue(D=1.) # set the value of D in the general form to 1. |
| 81 |
|
| 82 |
############################################FIRST TIME STEPS AND SOURCE |
| 83 |
# define small radius around point xc |
| 84 |
src_radius = 30 |
| 85 |
print "src_radius = ",src_radius |
| 86 |
# set initial values for first two time steps with source terms |
| 87 |
u=U0*(cos(length(x-xc)*3.1415/src_radius)+1)*whereNegative(length(x-xc)-src_radius) |
| 88 |
u_m1=u |
| 89 |
#plot source shape |
| 90 |
cut_loc=[] #where the cross section of the source along x will be |
| 91 |
src_cut=[] #where the cross section of the source will be |
| 92 |
# create locations for source cross section |
| 93 |
for i in range(ndx/2-ndx/10,ndx/2+ndx/10): |
| 94 |
cut_loc.append(xstep*i) |
| 95 |
src_cut.append([xstep*i,xc[1]]) |
| 96 |
# locate the nearest nodes to the points in src_cut |
| 97 |
src=Locator(mydomain,src_cut) |
| 98 |
src_cut=src.getValue(u) #retrieve the values from the nodes |
| 99 |
# plot the x locations vs value and save the figure |
| 100 |
pl.plot(cut_loc,src_cut) |
| 101 |
pl.axis([xc[0]-src_radius*3,xc[0]+src_radius*3,0.,2.*U0]) |
| 102 |
pl.savefig(os.path.join(savepath,"source_line.png")) |
| 103 |
|
| 104 |
####################################################ITERATION VARIABLES |
| 105 |
n=0 # iteration counter |
| 106 |
t=0 # time counter |
| 107 |
##############################################################ITERATION |
| 108 |
while t<tend: |
| 109 |
g=grad(u); pres=csq*h*h*g # get current pressure |
| 110 |
mypde.setValue(X=-pres,Y=(2.*u-u_m1)) # set values in pde |
| 111 |
u_p1 = mypde.getSolution() # get the new displacement |
| 112 |
u_m1=u; u=u_p1 # shift values back one time step for next iteration |
| 113 |
# save current displacement, acceleration and pressure |
| 114 |
if (t >= rtime): |
| 115 |
saveVTK(os.path.join(savepath,"ex07a.%i.vtu"%n),displacement=length(u),tensor=pres) |
| 116 |
rtime=rtime+rtime_inc #increment data save time |
| 117 |
# increment loop values |
| 118 |
t=t+h; n=n+1 |
| 119 |
print n,"-th time step t ",t |
Parent Directory
| 
Revision Log