1 | """Collection of culvert routines for use with Culvert_flow in culvert_class |
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2 | |
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3 | Usage: |
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4 | |
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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 | #NOTE: |
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10 | # Inlet control: Delta_Et > Es at the inlet |
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11 | # Outlet control: Delta_Et < Es at the inlet |
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12 | # where Et is total energy (w + 0.5*v^2/g) and |
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13 | # Es is the specific energy (h + 0.5*v^2/g) |
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14 | |
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15 | |
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16 | |
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17 | # NEW DEFINED CULVERT FLOW---- Flow from INLET 1 ------> INLET 2 (Outlet) |
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18 | # |
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19 | # The First Attempt has a Simple Horizontal Circle as a Hole on the Bed |
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20 | # Flow Is Removed at a Rate of INFLOW |
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21 | # Downstream there is a similar Circular Hole on the Bed where INFLOW effectively Surcharges |
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22 | # |
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23 | # This SHould be changed to a Vertical Opening Both BOX and Circular |
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24 | # There will be several Culvert Routines such as: |
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25 | # CULVERT_Boyd_Channel |
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26 | # CULVERT_Orifice_and_Weir |
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27 | # CULVERT_Simple_FLOOR |
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28 | # CULVERT_Simple_WALL |
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29 | # CULVERT_Eqn_Floor |
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30 | # CULVERT_Eqn_Wall |
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31 | # CULVERT_Tab_Floor |
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32 | # CULVERT_Tab_Wall |
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33 | # BRIDGES..... |
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34 | # NOTE NEED TO DEVELOP CONCEPT 1D Model for Linked Pipe System !!!! |
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35 | |
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36 | # COULD USE EPA SWMM Model !!!! |
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37 | |
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38 | |
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39 | from math import pi, sqrt, sin, cos |
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40 | |
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41 | |
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42 | def boyd_generalised_culvert_model(culvert, delta_total_energy, g): |
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43 | |
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44 | """Boyd's generalisation of the US department of transportation culvert model |
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45 | # == The quantity of flow passing through a culvert is controlled by many factors |
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46 | # == It could be that the culvert is controled by the inlet only, with it being Un submerged this is effectively equivalent to the WEIR Equation |
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47 | # == Else the culvert could be controlled by the inlet, with it being Submerged, this is effectively the Orifice Equation |
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48 | # == Else it may be controlled by Down stream conditions where depending on the down stream depth, the momentum in the culvert etc. flow is controlled |
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49 | """ |
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50 | |
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51 | from anuga.utilities.system_tools import log_to_file |
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52 | from anuga.config import velocity_protection |
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53 | from anuga.utilities.numerical_tools import safe_acos as acos |
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54 | |
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55 | inlet = culvert.inlet |
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56 | outlet = culvert.outlet |
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57 | Q_outlet_tailwater = 0.0 |
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58 | inlet.rate = 0.0 |
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59 | outlet.rate = 0.0 |
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60 | Q_inlet_unsubmerged = 0.0 |
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61 | Q_inlet_submerged = 0.0 |
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62 | Q_outlet_critical_depth = 0.0 |
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63 | |
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64 | if hasattr(culvert, 'log_filename'): |
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65 | log_filename = culvert.log_filename |
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66 | |
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67 | manning = culvert.manning |
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68 | sum_loss = culvert.sum_loss |
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69 | length = culvert.length |
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70 | |
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71 | if inlet.depth > 0.01: |
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72 | |
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73 | E = inlet.specific_energy |
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74 | |
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75 | if hasattr(culvert, 'log_filename'): |
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76 | s = 'Specific energy = %f m' %E |
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77 | log_to_file(log_filename, s) |
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78 | |
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79 | msg = 'Specific energy is negative' |
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80 | assert E >= 0.0, msg |
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81 | |
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82 | |
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83 | # Water has risen above inlet |
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84 | if culvert.culvert_type == 'circle': |
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85 | # Round culvert |
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86 | |
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87 | # Calculate flows for inlet control |
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88 | diameter = culvert.diameter |
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89 | |
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90 | Q_inlet_unsubmerged = 0.421*g**0.5*diameter**0.87*E**1.63 # Inlet Ctrl Inlet Unsubmerged |
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91 | Q_inlet_submerged = 0.530*g**0.5*diameter**1.87*E**0.63 # Inlet Ctrl Inlet Submerged |
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92 | |
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93 | if hasattr(culvert, 'log_filename'): |
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94 | s = 'Q_inlet_unsubmerged = %.6f, Q_inlet_submerged = %.6f' %(Q_inlet_unsubmerged, Q_inlet_submerged) |
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95 | log_to_file(log_filename, s) |
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96 | |
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97 | case = '' |
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98 | if Q_inlet_unsubmerged < Q_inlet_submerged: |
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99 | Q = Q_inlet_unsubmerged |
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100 | |
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101 | alpha = acos(1 - inlet.depth/diameter) |
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102 | flow_area = diameter**2 * (alpha - sin(alpha)*cos(alpha)) |
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103 | outlet_culvert_depth = inlet.depth |
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104 | width = diameter*sin(alpha) |
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105 | #perimeter = alpha*diameter |
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106 | case = 'Inlet unsubmerged' |
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107 | else: |
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108 | Q = Q_inlet_submerged |
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109 | flow_area = (diameter/2)**2 * pi |
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110 | outlet_culvert_depth = diameter |
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111 | width = diameter |
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112 | #perimeter = diameter |
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113 | case = 'Inlet submerged' |
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114 | |
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115 | |
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116 | |
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117 | if delta_total_energy < E: |
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118 | # Calculate flows for outlet control |
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119 | # Determine the depth at the outlet relative to the depth of flow in the Culvert |
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120 | |
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121 | if outlet.depth > diameter: # The Outlet is Submerged |
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122 | outlet_culvert_depth=diameter |
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123 | flow_area = (diameter/2)**2 * pi # Cross sectional area of flow in the culvert |
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124 | perimeter = diameter * pi |
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125 | width = diameter |
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126 | case = 'Outlet submerged' |
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127 | elif outlet.depth==0.0: |
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128 | outlet_culvert_depth=inlet.depth # For purpose of calculation assume the outlet depth = the inlet depth |
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129 | alpha = acos(1 - inlet.depth/diameter) |
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130 | flow_area = diameter**2 * (alpha - sin(alpha)*cos(alpha)) |
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131 | perimeter = alpha*diameter |
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132 | width = diameter*sin(alpha) |
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133 | |
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134 | case = 'Outlet depth is zero' |
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135 | else: # Here really should use the Culvert Slope to calculate Actual Culvert Depth & Velocity |
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136 | outlet_culvert_depth=outlet.depth # For purpose of calculation assume the outlet depth = the inlet depth |
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137 | alpha = acos(1 - outlet.depth/diameter) |
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138 | flow_area = diameter**2 * (alpha - sin(alpha)*cos(alpha)) |
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139 | perimeter = alpha*diameter |
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140 | width = diameter*sin(alpha) |
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141 | case = 'Outlet is open channel flow' |
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142 | |
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143 | hyd_rad = flow_area/perimeter |
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144 | |
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145 | if hasattr(culvert, 'log_filename'): |
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146 | s = 'hydraulic radius at outlet = %f' %hyd_rad |
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147 | log_to_file(log_filename, s) |
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148 | |
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149 | # Outlet control velocity using tail water |
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150 | culvert_velocity = sqrt(delta_total_energy/((sum_loss/2*g)+(manning**2*length)/hyd_rad**1.33333)) |
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151 | Q_outlet_tailwater = flow_area * culvert_velocity |
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152 | |
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153 | if hasattr(culvert, 'log_filename'): |
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154 | s = 'Q_outlet_tailwater = %.6f' %Q_outlet_tailwater |
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155 | log_to_file(log_filename, s) |
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156 | |
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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 | |
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163 | else: |
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164 | # Box culvert (rectangle or square) |
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165 | |
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166 | # Calculate flows for inlet control |
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167 | height = culvert.height |
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168 | width = culvert.width |
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169 | |
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170 | Q_inlet_unsubmerged = 0.540*g**0.5*width*E**1.50 # Flow based on Inlet Ctrl Inlet Unsubmerged |
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171 | Q_inlet_submerged = 0.702*g**0.5*width*height**0.89*E**0.61 # Flow based on Inlet Ctrl Inlet Submerged |
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172 | |
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173 | if hasattr(culvert, 'log_filename'): |
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174 | s = 'Q_inlet_unsubmerged = %.6f, Q_inlet_submerged = %.6f' %(Q_inlet_unsubmerged, Q_inlet_submerged) |
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175 | log_to_file(log_filename, s) |
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176 | |
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177 | case = '' |
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178 | if Q_inlet_unsubmerged < Q_inlet_submerged: |
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179 | Q = Q_inlet_unsubmerged |
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180 | flow_area = width*inlet.depth |
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181 | outlet_culvert_depth = inlet.depth |
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182 | #perimeter=(width+2.0*inlet.depth) |
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183 | case = 'Inlet unsubmerged' |
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184 | else: |
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185 | Q = Q_inlet_submerged |
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186 | flow_area = width*height |
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187 | outlet_culvert_depth = height |
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188 | #perimeter=2.0*(width+height) |
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189 | case = 'Inlet submerged' |
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190 | |
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191 | if delta_total_energy < E: |
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192 | # Calculate flows for outlet control |
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193 | # Determine the depth at the outlet relative to the depth of flow in the Culvert |
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194 | |
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195 | if outlet.depth > height: # The Outlet is Submerged |
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196 | outlet_culvert_depth=height |
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197 | flow_area=width*height # Cross sectional area of flow in the culvert |
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198 | perimeter=2.0*(width+height) |
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199 | case = 'Outlet submerged' |
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200 | elif outlet.depth==0.0: |
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201 | outlet_culvert_depth=inlet.depth # For purpose of calculation assume the outlet depth = the inlet depth |
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202 | flow_area=width*inlet.depth |
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203 | perimeter=(width+2.0*inlet.depth) |
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204 | case = 'Outlet depth is zero' |
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205 | else: # Here really should use the Culvert Slope to calculate Actual Culvert Depth & Velocity |
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206 | outlet_culvert_depth=outlet.depth |
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207 | flow_area=width*outlet.depth |
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208 | perimeter=(width+2.0*outlet.depth) |
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209 | case = 'Outlet is open channel flow' |
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210 | |
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211 | hyd_rad = flow_area/perimeter |
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212 | |
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213 | if hasattr(culvert, 'log_filename'): |
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214 | s = 'hydraulic radius at outlet = %f' %hyd_rad |
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215 | log_to_file(log_filename, s) |
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216 | |
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217 | # Outlet control velocity using tail water |
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218 | culvert_velocity = sqrt(delta_total_energy/((sum_loss/2*g)+(manning**2*length)/hyd_rad**1.33333)) |
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219 | Q_outlet_tailwater = flow_area * culvert_velocity |
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220 | |
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221 | if hasattr(culvert, 'log_filename'): |
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222 | s = 'Q_outlet_tailwater = %.6f' %Q_outlet_tailwater |
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223 | log_to_file(log_filename, s) |
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224 | Q = min(Q, Q_outlet_tailwater) |
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225 | else: |
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226 | pass |
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227 | #FIXME(Ole): What about inlet control? |
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228 | |
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229 | # Common code for circle and square geometries |
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230 | if hasattr(culvert, 'log_filename'): |
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231 | log_to_file(log_filename, 'Case: "%s"' %case) |
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232 | |
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233 | flow_rate_control=Q |
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234 | |
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235 | if hasattr(culvert, 'log_filename'): |
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236 | s = 'Flow Rate Control = %f' %flow_rate_control |
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237 | log_to_file(log_filename, s) |
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238 | |
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239 | inlet.rate = -flow_rate_control |
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240 | outlet.rate = flow_rate_control |
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241 | |
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242 | culv_froude=sqrt(flow_rate_control**2*width/(g*flow_area**3)) |
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243 | |
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244 | if hasattr(culvert, 'log_filename'): |
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245 | s = 'Froude in Culvert = %f' %culv_froude |
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246 | log_to_file(log_filename, s) |
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247 | |
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248 | # Determine momentum at the outlet |
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249 | barrel_velocity = Q/(flow_area + velocity_protection/flow_area) |
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250 | |
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251 | |
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252 | else: #inlet.depth < 0.01: |
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253 | Q = barrel_velocity = outlet_culvert_depth = 0.0 |
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254 | |
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255 | return Q, barrel_velocity, outlet_culvert_depth |
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256 | |
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257 | |
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