Outlet
Device Options
HydroCAD provides a wide range of basic pond outlet devices,
including orifice flow, weirs,
culverts, tubes, siphons, and
skimmers. These may be
used individually to model simple outlets,
or combined in various arrangements to model more complex outlets, such as a
riser structure or notched weir,
or even flow through rock-fill dams.
HydroCAD can also be used to model active outlet devices such as
pumps, or time-varying outlets such as a
dam breach or delayed
outlet, or to match a specific target outflow
hydrograph. Each pond can have an unlimited number of
outlet devices.
Many new outlet devices were added in HydroCAD-10,
including tubes, siphons, asymmetrical weirs, constant-flow devices (such as
floating weirs), and even a progressive dam breach. A direct channel
outlet was added in HydroCAD 10.1.
For devices than cannot be modeled with one of the standard outlet devices
listed above, a special outlet can be used to
define a custom stage-discharge curve. HydroCAD also includes a library of
predefined rating curves for certain proprietary devices, allowing them to be
easily modeled with a special outlet. Details
here.
Outlet Calculations
Complete details of the hydraulics calculations are provided in the
HydroCAD Reference Manual, as well as the built-in Help
system. Just click the help button on the outlet selection screen, or on a
specific outlet device.
Outlet Device Routing
The flow from each outlet device is routed to a specific node outflow.
By default, most devices are routed to primary. This causes their
flow to be directed to the primary outflow arrow on the routing diagram.
If desired, individual devices can also be routed to secondary or
tertiary. This causes their flow to be calculated and reported
separately, and makes it available as a separate outflow on the routing diagram.
Any number of devices can be routed to each outflow. When several
devices are routed to the same outflow, their individual flows are combined and
routed together.
Flows that are not subject to further routing (such as exfiltration), are
usually routed to the discarded outflow. The device routing can
also be used to construct compound outlet structures, such as a
riser.
Outlet Device Reporting
Click here for details on the outlet device
analysis.
