source: trunk/anuga_core/source/anuga/structures/boyd_box_culvert_routine.py @ 7984

Last change on this file since 7984 was 7984, checked in by steve, 12 years ago

Added enquiry points to culverts

File size: 8.2 KB
Line 
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
10import culvert_routine
11from anuga.config import velocity_protection
12from anuga.utilities.numerical_tools import safe_acos as acos
13
14from math import pi, sqrt, sin, cos
15from anuga.config import g
16
17
18class 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41        Note these documents have been superceded by: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
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