1 | #! /usr/bin/python |
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2 | |
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3 | # To change this template, choose Tools | Templates |
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4 | # and open the template in the editor. |
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5 | |
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6 | __author__="steve" |
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7 | __date__ ="$23/08/2010 5:18:51 PM$" |
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8 | |
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9 | |
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10 | import culvert_routine |
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11 | from anuga.config import velocity_protection |
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12 | from anuga.utilities.numerical_tools import safe_acos as acos |
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13 | |
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14 | from math import pi, sqrt, sin, cos |
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15 | from anuga.config import g |
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16 | |
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17 | |
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18 | class Boyd_box_culvert_routine(culvert_routine.Culvert_routine): |
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19 | """Boyd's generalisation of the US department of transportation culvert methods |
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20 | |
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21 | WARNING THIS IS A SIMPLISTIC APPROACH and OUTLET VELOCITIES ARE LIMITED TO EITHER |
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22 | FULL PIPE OR CRITICAL DEPTH ONLY |
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23 | For Supercritical flow this is UNDERESTIMATING the Outlet Velocity |
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24 | The obtain the CORRECT velocity requires an iteration of Depth to Establish |
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25 | the Normal Depth of flow in the pipe. |
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26 | |
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27 | It is proposed to provide this in a seperate routine called |
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28 | boyd_generalised_culvert_model_complex |
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29 | |
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30 | The Boyd Method is based on methods described by the following: |
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31 | 1. |
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32 | US Dept. Transportation Federal Highway Administration (1965) |
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33 | Hydraulic Chart for Selection of Highway Culverts. |
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34 | Hydraulic Engineering Circular No. 5 US Government Printing |
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35 | 2. |
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36 | US Dept. Transportation Federal Highway Administration (1972) |
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37 | Capacity charts for the Hydraulic design of highway culverts. |
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38 | Hydraulic Engineering Circular No. 10 US Government Printing |
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39 | These documents provide around 60 charts for various configurations of culverts and inlets. |
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40 | |
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41 | Note these documents have been superceded by: |
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42 | 2005 Hydraulic Design of Highway Culverts, Hydraulic Design Series No. 5 (HDS-5), |
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43 | Which combines culvert design information previously contained in Hydraulic Engineering Circulars |
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44 | (HEC) No. 5, No. 10, and No. 13 with hydrologic, storage routing, and special culvert design information. |
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45 | HEC-5 provides 20 Charts |
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46 | HEC-10 Provides an additional 36 Charts |
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47 | HEC-13 Discusses the Design of improved more efficient inlets |
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48 | HDS-5 Provides 60 sets of Charts |
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49 | |
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50 | In 1985 Professor Michael Boyd Published "Head-Discharge Relations for Culverts", and in |
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51 | 1987 published "Generalised Head Discharge Equations for Culverts". |
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52 | These papers reviewed the previous work by the US DOT and provided a simplistic approach for 3 configurations. |
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53 | |
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54 | It may be possible to extend the same approach for additional charts in the original work, but to date this has not been done. |
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55 | The additional charts cover a range of culvert shapes and inlet configurations |
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56 | |
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57 | |
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58 | """ |
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59 | |
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60 | def __init__(self, culvert, manning=0.0): |
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61 | |
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62 | culvert_routine.Culvert_routine.__init__(self, culvert, manning) |
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63 | |
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64 | |
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65 | |
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66 | def __call__(self): |
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67 | |
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68 | self.determine_inflow() |
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69 | |
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70 | local_debug ='false' |
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71 | |
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72 | if self.inflow.get_average_height() > 0.01: #this value was 0.01: |
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73 | if local_debug =='true': |
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74 | log.critical('Specific E & Deltat Tot E = %s, %s' |
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75 | % (str(self.inflow.get_average_specific_energy()), |
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76 | str(self.delta_total_energy))) |
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77 | log.critical('culvert type = %s' % str(culvert_type)) |
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78 | # Water has risen above inlet |
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79 | |
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80 | if self.log_filename is not None: |
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81 | s = 'Specific energy = %f m' % self.inflow.get_average_specific_energy() |
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82 | log_to_file(self.log_filename, s) |
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83 | |
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84 | msg = 'Specific energy at inlet is negative' |
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85 | assert self.inflow.get_average_specific_energy() >= 0.0, msg |
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86 | |
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87 | height = self.culvert_height |
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88 | width = self.culvert_width |
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89 | flow_width = self.culvert_width |
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90 | |
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91 | Q_inlet_unsubmerged = 0.540*g**0.5*width*self.inflow.get_average_specific_energy()**1.50 # Flow based on Inlet Ctrl Inlet Unsubmerged |
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92 | Q_inlet_submerged = 0.702*g**0.5*width*height**0.89*self.inflow.get_average_specific_energy()**0.61 # Flow based on Inlet Ctrl Inlet Submerged |
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93 | |
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94 | # FIXME(Ole): Are these functions really for inlet control? |
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95 | if Q_inlet_unsubmerged < Q_inlet_submerged: |
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96 | Q = Q_inlet_unsubmerged |
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97 | dcrit = (Q**2/g/width**2)**0.333333 |
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98 | if dcrit > height: |
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99 | dcrit = height |
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100 | flow_area = width*dcrit |
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101 | outlet_culvert_depth = dcrit |
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102 | case = 'Inlet unsubmerged Box Acts as Weir' |
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103 | else: |
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104 | Q = Q_inlet_submerged |
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105 | flow_area = width*height |
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106 | outlet_culvert_depth = height |
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107 | case = 'Inlet submerged Box Acts as Orifice' |
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108 | |
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109 | dcrit = (Q**2/g/width**2)**0.333333 |
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110 | |
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111 | outlet_culvert_depth = dcrit |
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112 | if outlet_culvert_depth > height: |
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113 | outlet_culvert_depth = height # Once again the pipe is flowing full not partfull |
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114 | flow_area = width*height # Cross sectional area of flow in the culvert |
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115 | perimeter = 2*(width+height) |
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116 | case = 'Inlet CTRL Outlet unsubmerged PIPE PART FULL' |
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117 | else: |
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118 | flow_area = width * outlet_culvert_depth |
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119 | perimeter = width+2*outlet_culvert_depth |
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120 | case = 'INLET CTRL Culvert is open channel flow we will for now assume critical depth' |
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121 | |
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122 | if self.delta_total_energy < self.inflow.get_average_specific_energy(): |
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123 | # Calculate flows for outlet control |
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124 | |
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125 | # Determine the depth at the outlet relative to the depth of flow in the Culvert |
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126 | if self.outflow.get_average_height() > height: # The Outlet is Submerged |
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127 | outlet_culvert_depth=height |
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128 | flow_area=width*height # Cross sectional area of flow in the culvert |
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129 | perimeter=2.0*(width+height) |
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130 | case = 'Outlet submerged' |
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131 | else: # Here really should use the Culvert Slope to calculate Actual Culvert Depth & Velocity |
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132 | dcrit = (Q**2/g/width**2)**0.333333 |
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133 | outlet_culvert_depth=dcrit # For purpose of calculation assume the outlet depth = Critical Depth |
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134 | if outlet_culvert_depth > height: |
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135 | outlet_culvert_depth=height |
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136 | flow_area=width*height |
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137 | perimeter=2.0*(width+height) |
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138 | case = 'Outlet is Flowing Full' |
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139 | else: |
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140 | flow_area=width*outlet_culvert_depth |
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141 | perimeter=(width+2.0*outlet_culvert_depth) |
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142 | case = 'Outlet is open channel flow' |
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143 | |
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144 | hyd_rad = flow_area/perimeter |
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145 | |
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146 | if self.log_filename is not None: |
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147 | s = 'hydraulic radius at outlet = %f' % hyd_rad |
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148 | log_to_file(self.log_filename, s) |
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149 | |
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150 | # Outlet control velocity using tail water |
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151 | culvert_velocity = sqrt(self.delta_total_energy/((self.sum_loss/2/g)+(self.manning**2*self.culvert_length)/hyd_rad**1.33333)) |
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152 | Q_outlet_tailwater = flow_area * culvert_velocity |
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153 | |
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154 | if self.log_filename is not None: |
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155 | s = 'Q_outlet_tailwater = %.6f' % Q_outlet_tailwater |
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156 | log_to_file(self.log_filename, s) |
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157 | Q = min(Q, Q_outlet_tailwater) |
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158 | else: |
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159 | pass |
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160 | #FIXME(Ole): What about inlet control? |
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161 | |
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162 | culv_froude=sqrt(Q**2*flow_width/(g*flow_area**3)) |
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163 | if local_debug =='true': |
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164 | log.critical('FLOW AREA = %s' % str(flow_area)) |
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165 | log.critical('PERIMETER = %s' % str(perimeter)) |
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166 | log.critical('Q final = %s' % str(Q)) |
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167 | log.critical('FROUDE = %s' % str(culv_froude)) |
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168 | |
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169 | # Determine momentum at the outlet |
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170 | barrel_velocity = Q/(flow_area + velocity_protection/flow_area) |
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171 | |
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172 | # END CODE BLOCK for DEPTH > Required depth for CULVERT Flow |
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173 | |
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174 | else: # self.inflow.get_average_height() < 0.01: |
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175 | Q = barrel_velocity = outlet_culvert_depth = 0.0 |
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176 | |
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177 | # Temporary flow limit |
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178 | if barrel_velocity > self.max_velocity: |
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179 | barrel_velocity = self.max_velocity |
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180 | Q = flow_area * barrel_velocity |
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181 | |
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182 | |
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183 | |
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184 | |
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185 | |
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186 | return Q, barrel_velocity, outlet_culvert_depth |
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187 | |
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188 | |
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189 | |
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