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41 | Note these documents have been superceded by: |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