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__ ="$30/08/2010 10:15:08 AM$" |
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8 | |
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9 | import culvert_routine |
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10 | from anuga.config import velocity_protection |
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11 | from anuga.utilities.numerical_tools import safe_acos as acos |
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12 | |
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13 | from math import pi, sqrt, sin, cos |
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14 | from anuga.config import g |
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15 | |
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16 | |
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17 | class Boyd_box_routine(culvert_routine.Culvert_routine): |
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18 | """Boyd's generalisation of the US department of transportation culvert methods |
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19 | |
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20 | WARNING THIS IS A SIMPLISTIC APPROACH and OUTLET VELOCITIES ARE LIMITED TO EITHER |
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21 | FULL PIPE OR CRITICAL DEPTH ONLY |
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22 | For Supercritical flow this is UNDERESTIMATING the Outlet Velocity |
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23 | The obtain the CORRECT velocity requires an iteration of Depth to Establish |
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24 | the Normal Depth of flow in the pipe. |
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25 | |
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26 | It is proposed to provide this in a seperate routine called |
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27 | boyd_generalised_culvert_model_complex |
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28 | |
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29 | The Boyd Method is based on methods described by the following: |
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30 | 1. |
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31 | US Dept. Transportation Federal Highway Administration (1965) |
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32 | Hydraulic Chart for Selection of Highway Culverts. |
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33 | Hydraulic Engineering Circular No. 5 US Government Printing |
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34 | 2. |
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35 | US Dept. Transportation Federal Highway Administration (1972) |
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36 | Capacity charts for the Hydraulic design of highway culverts. |
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37 | Hydraulic Engineering Circular No. 10 US Government Printing |
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38 | These documents provide around 60 charts for various configurations of culverts and inlets. |
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39 | |
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40 | Note these documents have been superceded by: |
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41 | 2005 Hydraulic Design of Highway Culverts, Hydraulic Design Series No. 5 (HDS-5), |
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42 | Which combines culvert design information previously contained in Hydraulic Engineering Circulars |
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43 | (HEC) No. 5, No. 10, and No. 13 with hydrologic, storage routing, and special culvert design information. |
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44 | HEC-5 provides 20 Charts |
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45 | HEC-10 Provides an additional 36 Charts |
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46 | HEC-13 Discusses the Design of improved more efficient inlets |
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47 | HDS-5 Provides 60 sets of Charts |
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48 | |
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49 | In 1985 Professor Michael Boyd Published "Head-Discharge Relations for Culverts", and in |
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50 | 1987 published "Generalised Head Discharge Equations for Culverts". |
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51 | These papers reviewed the previous work by the US DOT and provided a simplistic approach for 3 configurations. |
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52 | |
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53 | 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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54 | The additional charts cover a range of culvert shapes and inlet configurations |
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55 | |
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56 | |
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57 | """ |
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58 | |
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59 | def __init__(self): |
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60 | |
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61 | Culvert_routine.__init__(self) |
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62 | |
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63 | |
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64 | |
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65 | def __call__(self): |
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66 | |
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67 | """ |
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68 | For a circular pipe the Boyd method reviews 3 conditions |
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69 | 1. Whether the Pipe Inlet is Unsubmerged (acting as weir flow into the inlet) |
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70 | 2. Whether the Pipe Inlet is Fully Submerged (acting as an Orifice) |
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71 | 3. Whether the energy loss in the pipe results in the Pipe being controlled by Channel Flow of the Pipe |
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72 | |
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73 | For these conditions we also would like to assess the pipe flow characteristics as it leaves the pipe |
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74 | """ |
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75 | |
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76 | diameter = self.culvert_height |
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77 | |
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78 | local_debug ='false' |
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79 | if self.inflow.get_average_height() > 0.1: #this value was 0.01: |
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80 | if local_debug =='true': |
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81 | log.critical('Specific E & Deltat Tot E = %s, %s' |
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82 | % (str(self.inflow.get_average_specific_energy()), |
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83 | str(self.delta_total_energy))) |
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84 | log.critical('culvert type = %s' % str(culvert_type)) |
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85 | # Water has risen above inlet |
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86 | |
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87 | if self.log_filename is not None: |
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88 | s = 'Specific energy = %f m' % self.inflow.get_average_specific_energy() |
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89 | log_to_file(self.log_filename, s) |
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90 | |
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91 | msg = 'Specific energy at inlet is negative' |
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92 | assert self.inflow.get_average_specific_energy() >= 0.0, msg |
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93 | |
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94 | # Calculate flows for inlet control |
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95 | Q_inlet_unsubmerged = 0.421*g**0.5*diameter**0.87*self.inflow.get_average_specific_energy()**1.63 # Inlet Ctrl Inlet Unsubmerged |
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96 | Q_inlet_submerged = 0.530*g**0.5*diameter**1.87*self.inflow.get_average_specific_energy()**0.63 # Inlet Ctrl Inlet Submerged |
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97 | # Note for to SUBMERGED TO OCCUR self.inflow.get_average_specific_energy() should be > 1.2 x diameter.... Should Check !!! |
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98 | |
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99 | if self.log_filename is not None: |
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100 | s = 'Q_inlet_unsubmerged = %.6f, Q_inlet_submerged = %.6f' % (Q_inlet_unsubmerged, Q_inlet_submerged) |
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101 | log_to_file(self.log_filename, s) |
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102 | Q = min(Q_inlet_unsubmerged, Q_inlet_submerged) |
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103 | |
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104 | # THE LOWEST Value will Control Calcs From here |
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105 | # Calculate Critical Depth Based on the Adopted Flow as an Estimate |
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106 | dcrit1 = diameter/1.26*(Q/g**0.5*diameter**2.5)**(1/3.75) |
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107 | dcrit2 = diameter/0.95*(Q/g**0.5*diameter**2.5)**(1/1.95) |
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108 | # From Boyd Paper ESTIMATE of Dcrit has 2 criteria as |
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109 | if dcrit1/diameter > 0.85: |
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110 | outlet_culvert_depth = dcrit2 |
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111 | else: |
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112 | outlet_culvert_depth = dcrit1 |
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113 | #outlet_culvert_depth = min(outlet_culvert_depth, diameter) |
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114 | # Now determine Hydraulic Radius Parameters Area & Wetted Perimeter |
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115 | if outlet_culvert_depth >= diameter: |
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116 | outlet_culvert_depth = diameter # Once again the pipe is flowing full not partfull |
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117 | flow_area = (diameter/2)**2 * pi # Cross sectional area of flow in the culvert |
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118 | perimeter = diameter * pi |
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119 | flow_width= diameter |
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120 | case = 'Inlet CTRL Outlet submerged Circular PIPE FULL' |
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121 | if local_debug == 'true': |
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122 | log.critical('Inlet CTRL Outlet submerged Circular ' |
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123 | 'PIPE FULL') |
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124 | else: |
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125 | #alpha = acos(1 - outlet_culvert_depth/diameter) # Where did this Come From ????/ |
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126 | alpha = acos(1-2*outlet_culvert_depth/diameter)*2 |
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127 | #flow_area = diameter**2 * (alpha - sin(alpha)*cos(alpha)) # Pipe is Running Partly Full at the INLET WHRE did this Come From ????? |
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128 | flow_area = diameter**2/8*(alpha - sin(alpha)) # Equation from GIECK 5th Ed. Pg. B3 |
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129 | flow_width= diameter*sin(alpha/2.0) |
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130 | perimeter = alpha*diameter/2.0 |
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131 | case = 'INLET CTRL Culvert is open channel flow we will for now assume critical depth' |
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132 | if local_debug =='true': |
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133 | log.critical('INLET CTRL Culvert is open channel flow ' |
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134 | 'we will for now assume critical depth') |
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135 | log.critical('Q Outlet Depth and ALPHA = %s, %s, %s' |
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136 | % (str(Q), str(outlet_culvert_depth), |
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137 | str(alpha))) |
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138 | if self.delta_total_energy < self.inflow.get_average_specific_energy(): # OUTLET CONTROL !!!! |
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139 | # Calculate flows for outlet control |
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140 | |
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141 | # Determine the depth at the outlet relative to the depth of flow in the Culvert |
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142 | if self.outflow.get_average_height() > diameter: # Outlet is submerged Assume the end of the Pipe is flowing FULL |
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143 | outlet_culvert_depth=diameter |
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144 | flow_area = (diameter/2)**2 * pi # Cross sectional area of flow in the culvert |
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145 | perimeter = diameter * pi |
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146 | flow_width= diameter |
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147 | case = 'Outlet submerged' |
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148 | if local_debug =='true': |
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149 | log.critical('Outlet submerged') |
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150 | else: # Culvert running PART FULL for PART OF ITS LENGTH Here really should use the Culvert Slope to calculate Actual Culvert Depth & Velocity |
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151 | # IF self.outflow.get_average_height() < diameter |
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152 | dcrit1 = diameter/1.26*(Q/g**0.5*diameter**2.5)**(1/3.75) |
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153 | dcrit2 = diameter/0.95*(Q/g**0.5*diameter**2.5)**(1/1.95) |
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154 | if dcrit1/diameter >0.85: |
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155 | outlet_culvert_depth= dcrit2 |
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156 | else: |
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157 | outlet_culvert_depth = dcrit1 |
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158 | if outlet_culvert_depth > diameter: |
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159 | outlet_culvert_depth = diameter # Once again the pipe is flowing full not partfull |
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160 | flow_area = (diameter/2)**2 * pi # Cross sectional area of flow in the culvert |
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161 | perimeter = diameter * pi |
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162 | flow_width= diameter |
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163 | case = 'Outlet unsubmerged PIPE FULL' |
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164 | if local_debug =='true': |
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165 | log.critical('Outlet unsubmerged PIPE FULL') |
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166 | else: |
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167 | alpha = acos(1-2*outlet_culvert_depth/diameter)*2 |
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168 | flow_area = diameter**2/8*(alpha - sin(alpha)) # Equation from GIECK 5th Ed. Pg. B3 |
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169 | flow_width= diameter*sin(alpha/2.0) |
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170 | perimeter = alpha*diameter/2.0 |
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171 | case = 'Outlet is open channel flow we will for now assume critical depth' |
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172 | if local_debug == 'true': |
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173 | log.critical('Q Outlet Depth and ALPHA = %s, %s, %s' |
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174 | % (str(Q), str(outlet_culvert_depth), |
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175 | str(alpha))) |
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176 | log.critical('Outlet is open channel flow we ' |
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177 | 'will for now assume critical depth') |
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178 | if local_debug == 'true': |
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179 | log.critical('FLOW AREA = %s' % str(flow_area)) |
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180 | log.critical('PERIMETER = %s' % str(perimeter)) |
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181 | log.critical('Q Interim = %s' % str(Q)) |
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182 | hyd_rad = flow_area/perimeter |
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183 | |
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184 | if self.log_filename is not None: |
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185 | s = 'hydraulic radius at outlet = %f' %hyd_rad |
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186 | log_to_file(self.log_filename, s) |
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187 | |
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188 | # Outlet control velocity using tail water |
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189 | if local_debug =='true': |
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190 | log.critical('GOT IT ALL CALCULATING Velocity') |
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191 | log.critical('HydRad = %s' % str(hyd_rad)) |
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192 | 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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193 | Q_outlet_tailwater = flow_area * culvert_velocity |
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194 | if local_debug =='true': |
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195 | log.critical('VELOCITY = %s' % str(culvert_velocity)) |
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196 | log.critical('Outlet Ctrl Q = %s' % str(Q_outlet_tailwater)) |
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197 | if self.log_filename is not None: |
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198 | s = 'Q_outlet_tailwater = %.6f' %Q_outlet_tailwater |
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199 | log_to_file(self.log_filename, s) |
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200 | Q = min(Q, Q_outlet_tailwater) |
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201 | if local_debug =='true': |
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202 | log.critical('%s,%.3f,%.3f' |
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203 | % ('dcrit 1 , dcit2 =',dcrit1,dcrit2)) |
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204 | log.critical('%s,%.3f,%.3f,%.3f' |
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205 | % ('Q and Velocity and Depth=', Q, |
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206 | culvert_velocity, outlet_culvert_depth)) |
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207 | |
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208 | culv_froude=sqrt(Q**2*flow_width/(g*flow_area**3)) |
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209 | if local_debug =='true': |
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210 | log.critical('FLOW AREA = %s' % str(flow_area)) |
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211 | log.critical('PERIMETER = %s' % str(perimeter)) |
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212 | log.critical('Q final = %s' % str(Q)) |
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213 | log.critical('FROUDE = %s' % str(culv_froude)) |
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214 | |
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215 | # Determine momentum at the outlet |
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216 | barrel_velocity = Q/(flow_area + velocity_protection/flow_area) |
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217 | |
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218 | else: # self.inflow.get_average_height() < 0.01: |
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219 | Q = barrel_velocity = outlet_culvert_depth = 0.0 |
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220 | |
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221 | # Temporary flow limit |
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222 | if barrel_velocity > self.max_velocity: |
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223 | barrel_velocity = self.max_velocity |
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224 | Q = flow_area * barrel_velocity |
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225 | |
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226 | return Q, barrel_velocity, outlet_culvert_depth |
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227 | |
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228 | |
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229 | |
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