[Anuga-user] boyd_pipe_operator

[S.Kummer <ste...@we...>]

Hi ANUGA users,

I'm using the boyd_pipe_operator in a rainfall
surface-runoff-simulation.
- pipe diameter: 0.4 m
- pipe length: 42 m
- slope: 4 %
- manning: 0.012

Here is the output of the culvert.print_timestepping_statistics()
after a simulation time of 1530 sec:

Structure report for Culvert__Nr1_DN400:
--------------------------
Type: boyd_pipe
inlets[0]_enquiry_depth [m]:  0.75
inlets[0]_enquiry_speed [m/s]:  0.75
inlets[0]_enquiry_stage [m]:  452.65
inlets[0]_enquiry_elevation [m]:  451.90
inlets[0]_average_depth [m]:  0.86
inlets[0]_average_speed [m/s]:  0.46
inlets[0]_average_stage [m]:  452.62
inlets[0]_average_elevation [m]:  451.77

inlets[1]_enquiry_depth [m]:  0.02
inlets[1]_enquiry_speed [m/s]:  0.22
inlets[1]_enquiry_stage [m]:  450.98
inlets[1]_enquiry_elevation [m]:  450.96
inlets[1]_average_depth [m]:  0.32
inlets[1]_average_speed [m/s]:  0.00
inlets[1]_average_stage [m]:  450.96
inlets[1]_average_elevation [m]:  450.65
Discharge [m^3/s]: 0.05
Discharge_function_value [m^3/s]: 4.24
Velocity  [m/s]: 2.33
Outlet Depth  [m]: 0.09
Accumulated Flow [m^3]: 42.36
Inlet Driving Energy 0.75
Delta Total Energy 1.67
Control at this instant: INLET CTRL Culvert is open channel flow we
will for now assume critical depth
--------------------------

The culvert crosses a road.
In my depth-animation the road is overtopping although the culvert is
in open channel flow and the full capacity of the culvert is obviously
not reached!?

Are the enquiry-values calculated at the given endpoints and the
average-values as the average of the triangles which are taken in
account?

How is it possible that the discharge is 0.05 m3/s at a velocity of
2.33 m/s and a diameter of 0.4 m (continuity equation: Q = 0.2^2 * PI
* 2.33 = 0.29 m3/s)?



Cheers
Stefan