/[escript]/trunk/doc/examples/cookbook/onedheatdiff001.py
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Annotation of /trunk/doc/examples/cookbook/onedheatdiff001.py

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Wed Aug 26 22:18:19 2009 UTC (11 years, 5 months ago) by ahallam
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Regigger of cookbook directory structure. Examlples->examples/cookbook TEXT->doc/cookbook Figures-> doc/cookbook/figures
1 ahallam 2401
2     ########################################################
3     #
4     # Copyright (c) 2003-2009 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) 2003-2009 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     """
23     Author: Antony Hallam antony.hallam@uqconnect.edu.au
24     """
25 ahallam 2606 ############################################################FILE HEADER
26     # onedheatdiff001.py
27     # Model temperature diffusion in an Iron bar. This is a one dimensional
28     # problem with a single heat source at the LHS
29 ahallam 2401
30 ahallam 2606 #######################################################EXTERNAL MODULES
31     #To solve the problem it is necessary to import the modules we require.
32     #This imports everything from the escript library
33     from esys.escript import *
34     # This defines the LinearPDE module as LinearPDE
35     from esys.escript.linearPDEs import LinearPDE
36     # This imports the rectangle domain function from finley.
37     from esys.finley import Rectangle
38     # A useful unit handling package which will make sure all our units
39     # match up in the equations under SI.
40     from esys.escript.unitsSI import *
41     import pylab as pl #Plotting package.
42     import numpy as np #Array package.
43 ahallam 2401 import os #This package is necessary to handle saving our data.
44    
45 ahallam 2606 #################################################ESTABLISHING VARIABLES
46 ahallam 2401 #Domain related.
47 ahallam 2606 mx = 1*m #meters - model length
48 ahallam 2494 my = .1*m #meters - model width
49 ahallam 2606 ndx = 100 # mesh steps in x direction
50     ndy = 1 # mesh steps in y direction - one dimension means one element
51 ahallam 2401
52     #PDE related
53 ahallam 2494 q=200. * Celsius #Kelvin - our heat source temperature
54 ahallam 2606 Tref = 0. * Celsius #Kelvin - starting temp of iron bar
55 ahallam 2494 rho = 7874. *kg/m**3 #kg/m^{3} density of iron
56     cp = 449.*J/(kg*K) #j/Kg.K thermal capacity
57 ahallam 2401 rhocp = rho*cp
58 ahallam 2494 kappa = 80.*W/m/K #watts/m.Kthermal conductivity
59 ahallam 2606
60 ahallam 2401 #Script/Iteration Related
61     t=0 #our start time, usually zero
62 ahallam 2494 tend=5.*minute #seconds - time to end simulation
63 ahallam 2401 outputs = 200 # number of time steps required.
64     h=(tend-t)/outputs #size of time step
65 ahallam 2606 #user warning statement
66 ahallam 2494 print "Expected Number of time outputs is: ", (tend-t)/h
67 ahallam 2401 i=0 #loop counter
68     #the folder to put our outputs in, leave blank "" for script path
69 ahallam 2494 save_path="data/onedheatdiff001"
70 ahallam 2606 ########## note this folder path must exist to work ###################
71 ahallam 2401
72 ahallam 2606 ################################################ESTABLISHING PARAMETERS
73     #generate domain using rectangle
74 ahallam 2401 rod = Rectangle(l0=mx,l1=my,n0=ndx, n1=ndy)
75 ahallam 2606 #extract finite points - the solution points
76 ahallam 2401 x=rod.getX()
77 ahallam 2606 #create the PDE
78     mypde=LinearPDE(rod) #assigns a domain to our PDE
79     mypde.setSymmetryOn() #set the fast solver on for symmetry
80     mypde.setValue(A=kappa*kronecker(rod),D=rhocp/h) #define our PDE coeffs
81     qH=q*whereZero(x[0]) #set heat source
82     T=Tref # set initial temperature
83 ahallam 2401
84 ahallam 2606 #convert solution points for plotting
85     plx = x.toListOfTuples()
86     plx = np.array(plx) #convert to tuple to numpy array
87     plx = plx[:,0] #extract x locations
88 ahallam 2401
89 ahallam 2606 ########################################################START ITERATION
90 ahallam 2401 while t<=tend:
91 ahallam 2606 i+=1 #increment the counter
92     t+=h #increment the current time
93     mypde.setValue(Y=qH+rhocp/h*T) #set variable PDE coefficients
94     T=mypde.getSolution() #get the PDE solution
95     totT = rhocp*T #get the total heat solution in the system
96    
97     #establish figure 1 for temperature vs x plots
98 ahallam 2589 tempT = T.toListOfTuples(scalarastuple=False)
99 ahallam 2606 pl.figure(1) #current figure
100     pl.plot(plx,tempT) #plot solution
101     #define axis extents and title
102     pl.axis([0,1.0,273.14990+0.00008,0.004+273.1499])
103     pl.title("Temperature accross Rod")
104     #save figure to file
105     pl.savefig(os.path.join(save_path+"/tempT","rodpyplot%03d.png") %i)
106     pl.clf() #clear figure
107    
108     #establish figure 2 for total temperature vs x plots and repeat
109     tottempT = totT.toListOfTuples(scalarastuple=False)
110     pl.figure(2)
111     pl.plot(plx,tottempT)
112     pl.axis([0,1.0,9.657E08,12000+9.657E08])
113     pl.title("Total temperature accross Rod")
114     pl.savefig(os.path.join(save_path+"/totT","ttrodpyplot%03d.png")%i)
115     pl.clf()
116 ahallam 2401
117 ahallam 2606 # compile the *.png files to create two *.avi videos that show T change
118     # with time. This opperation uses linux mencoder. For other operating
119     # systems it is possible to use your favourite video compiler to
120     # convert image files to videos.
121    
122     os.system("mencoder mf://"+save_path+"/tempT"+"/*.png -mf type=png:\
123     w=800:h=600:fps=25 -ovc lavc -lavcopts vcodec=mpeg4 -oac copy -o \
124     onedheatdiff001tempT.avi")
125    
126     os.system("mencoder mf://"+save_path+"/totT"+"/*.png -mf type=png:\
127     w=800:h=600:fps=25 -ovc lavc -lavcopts vcodec=mpeg4 -oac copy -o \
128     onedheatdiff001totT.avi")

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