Culvert Inlets
Inlet and outlet losses for a culvert can be specified as part of a conduit when you set the Conduit type property to Culvert. See the Conduit Data Fields for further information.
This topic refers to the method where the inlet and outlet losses for a culvert are specified separately using culvert inlet and culvert outlet controls. The inlet and outlet controls are defined in the Hydraulic Design of Highway Culverts, Third Edition published by FHWA.
Using this method, three links are required to define a culvert:
- Culvert inlet used to define inlet controls - see the Culvert Inlet Data Fields
- Conduit representing the culvert itself - see the Conduit Data Fields
- Culvert outlet used to define outlet controls - see the Culvert Outlet Data Fields
When using the three link method, the Conduit type field for the conduit should be set to Conduit, and both the upstream and downstream headloss types for the conduit should be set to NONE.
Inlet control parameters
The equations governing inlet losses include several empirical variables. The values for which can be automatically set by the software if the #D flag is set on the applicable properties. These values are derived from the Hydraulic Design of Highway Culverts publication (and earlier research), and depend on the selected Culvert code (shape and material, and inlet and edge type, see figure below). See Culvert Inlet Data Fields for further information.
Typical values for the various inlet control parameters can be found in the FHWA guide.
