1 | """Example of shallow water wave equation. |
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2 | |
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3 | This is called Netherlands because it shows a dam with a gap in it and |
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4 | stylised housed behind it and below the water surface. |
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5 | |
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6 | """ |
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7 | |
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8 | ###################### |
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9 | # Module imports |
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10 | # |
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11 | from shallow_water import Domain, Reflective_boundary, Dirichlet_boundary,\ |
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12 | Transmissive_boundary, Constant_height |
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13 | |
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14 | from mesh_factory import rectangular |
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15 | from Numeric import array |
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16 | |
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17 | |
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18 | class Weir: |
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19 | """Set a bathymetry for simple weir with a hole. |
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20 | x,y are assumed to be in the unit square |
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21 | """ |
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22 | |
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23 | def __init__(self, stage): |
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24 | self.inflow_stage = stage |
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25 | |
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26 | def __call__(self, x, y): |
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27 | from Numeric import zeros, Float |
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28 | |
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29 | N = len(x) |
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30 | assert N == len(y) |
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31 | |
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32 | z = zeros(N, Float) |
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33 | for i in range(N): |
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34 | z[i] = -x[i]/20 #General slope |
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35 | |
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36 | #Flattish bit to the left |
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37 | if x[i] <= 0.3: |
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38 | #z[i] = -x[i]/5 |
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39 | z[i] = -x[i]/20 |
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40 | |
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41 | |
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42 | #Weir |
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43 | if x[i] > 0.3 and x[i] < 0.4: |
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44 | z[i] = -x[i]/20+1.2 |
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45 | |
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46 | #Dip |
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47 | #if x[i] > 0.6 and x[i] < 0.9: |
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48 | # z[i] = -x[i]/20-0.5 #-y[i]/5 |
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49 | |
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50 | #Hole in weir |
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51 | #if x[i] > 0.3 and x[i] < 0.4 and y[i] > 0.2 and y[i] < 0.4: |
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52 | if x[i] > 0.3 and x[i] < 0.4 and y[i] > 0.4 and y[i] < 0.6: |
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53 | #z[i] = -x[i]/5 |
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54 | z[i] = -x[i]/20 |
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55 | |
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56 | #Poles |
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57 | #if x[i] > 0.65 and x[i] < 0.8 and y[i] > 0.55 and y[i] < 0.65 or\ |
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58 | # x[i] > 0.75 and x[i] < 0.9 and y[i] > 0.35 and y[i] < 0.45: |
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59 | # z[i] = -x[i]/20+0.4 |
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60 | |
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61 | if (x[i] - 0.72)**2 + (y[i] - 0.6)**2 < 0.05**2:# or\ |
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62 | #x[i] > 0.75 and x[i] < 0.9 and y[i] > 0.35 and y[i] < 0.45: |
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63 | z[i] = -x[i]/20+0.4 |
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64 | |
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65 | #Wall |
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66 | if x[i] > 0.995: |
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67 | z[i] = -x[i]/20+0.3 |
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68 | |
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69 | return z/2 |
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70 | |
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71 | |
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72 | |
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73 | ###################### |
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74 | # Domain |
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75 | # |
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76 | |
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77 | N = 250 |
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78 | #N= 8 |
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79 | N = 16 |
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80 | #N = 4 |
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81 | #N = 102 |
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82 | N = 25 |
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83 | N = 16 |
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84 | N = 60 |
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85 | N = 150 #size = 45000 |
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86 | N = 130 #size = 33800 |
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87 | #N = 60 |
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88 | #N = 40 |
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89 | N = 260 |
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90 | #N = 150 |
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91 | N = 264 |
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92 | |
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93 | N = 600 #Size = 720000 |
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94 | N = 20 |
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95 | #N = 150 |
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96 | N = 110 |
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97 | N = 60 |
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98 | |
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99 | #N = 140 |
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100 | |
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101 | N = 15 |
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102 | |
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103 | print 'Creating domain' |
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104 | #Create basic mesh |
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105 | points, vertices, boundary = rectangular(N, N) |
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106 | |
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107 | #Create shallow water domain |
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108 | domain = Domain(points, vertices, boundary) |
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109 | |
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110 | domain.check_integrity() |
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111 | domain.default_order = 2 |
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112 | |
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113 | #Output params |
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114 | domain.smooth = True |
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115 | domain.reduction = min #Looks a lot better on top of steep slopes |
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116 | |
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117 | print "Number of triangles = ", len(domain) |
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118 | |
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119 | |
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120 | if N > 40: |
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121 | domain.visualise = False |
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122 | domain.checkpoint = False |
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123 | domain.store = True #Store for visualisation purposes |
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124 | domain.format = 'sww' #Native netcdf visualisation format |
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125 | import sys, os |
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126 | #FIXME: This was os.path.splitext but caused weird filenames based on root |
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127 | base = os.path.basename(sys.argv[0]) |
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128 | domain.filename, _ = os.path.splitext(base) |
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129 | else: |
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130 | domain.visualise = True |
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131 | domain.checkpoint = False |
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132 | domain.store = False |
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133 | |
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134 | |
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135 | #Set bed-slope and friction |
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136 | inflow_stage = 0.08 |
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137 | manning = 0.02 |
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138 | Z = Weir(inflow_stage) |
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139 | |
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140 | print 'Field values' |
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141 | domain.set_quantity('elevation', Z) |
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142 | domain.set_quantity('friction', manning) |
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143 | |
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144 | |
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145 | ###################### |
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146 | # Boundary conditions |
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147 | # |
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148 | print 'Boundaries' |
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149 | Br = Reflective_boundary(domain) |
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150 | Bt = Transmissive_boundary(domain) |
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151 | |
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152 | #Constant inflow |
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153 | Bd = Dirichlet_boundary([2*inflow_stage, 0.0, 0.0]) |
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154 | |
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155 | |
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156 | #Set boundary conditions |
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157 | domain.set_boundary({'left': Bd, 'right': Br, 'bottom': Br, 'top': Br}) |
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158 | |
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159 | |
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160 | ###################### |
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161 | #Initial condition |
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162 | # |
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163 | print 'Initial condition' |
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164 | domain.set_quantity('stage', Constant_height(Z, 0.)) |
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165 | |
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166 | #Evolve |
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167 | import time |
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168 | t0 = time.time() |
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169 | |
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170 | for t in domain.evolve(yieldstep = 0.01, finaltime = 7.0): |
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171 | domain.write_time() |
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172 | |
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173 | print 'That took %.2f seconds' %(time.time()-t0) |
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174 | |
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