1 | """Example using the module for solving the advection equation |
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2 | |
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3 | |
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4 | Initial condition is zero, boundary conditions are transmissive everywhere except |
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5 | for three segments where three different time dependent conditions are applied. |
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6 | """ |
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7 | import sys |
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8 | from os import sep |
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9 | sys.path.append('..'+sep+'pyvolution') |
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10 | |
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11 | from mesh_factory import rectangular |
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12 | from advection import Domain, Transmissive_boundary, Dirichlet_boundary, Time_boundary |
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13 | |
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14 | #Create basic mesh |
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15 | points, vertices, boundary = rectangular(20, 4) |
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16 | |
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17 | #Create advection domain |
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18 | # - Initial condition is zero by default |
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19 | domain = Domain(points, vertices, boundary, velocity=[1.0, -0.8]) |
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20 | #domain.smooth = False |
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21 | domain.visualise = True |
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22 | |
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23 | #Boundaries |
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24 | T = Transmissive_boundary(domain) |
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25 | D = Dirichlet_boundary([0.1]) |
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26 | |
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27 | from math import sin, pi |
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28 | T1 = Time_boundary(domain, f=lambda x: [0.2*(sin(2*x*pi)+1)/2]) |
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29 | T2 = Time_boundary(domain, f=lambda x: [0.2*(sin(4*x*pi)+1)/3]) |
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30 | T3 = Time_boundary(domain, f=lambda x: [0.2*(sin(6*x*pi)+1)/4]) |
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31 | |
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32 | #Modify boundary tags |
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33 | domain.boundary[(7, 1)] = 't1' |
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34 | domain.boundary[(5, 2)] = 't2' |
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35 | domain.boundary[(3, 2)] = 't3' |
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36 | |
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37 | domain.set_boundary( {'left': T, 'right': T, 'bottom': T, 'top': T, |
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38 | 't1': T1, 't2': T2, 't3': T3} ) |
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39 | domain.check_integrity() |
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40 | |
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41 | |
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42 | ################### |
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43 | # Evolution |
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44 | for t in domain.evolve(yieldstep = 0.02, finaltime = None): |
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45 | domain.write_time() |
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46 | |
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47 | |
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48 | |
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49 | |
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