HY8:Channel Shape

There are three available channel shapes to define the downstream tailwater channel: rectangular, trapezoidal, and triangular. When selecting a channel shape the input window adjusts to display only those parameters required for the defined shape. When defining a channel shape, the following channel properties are required for analysis:

• Bottom Width — Width of the channel at the downstream section, shown in drawing below.
• Side Slope (H:V) (_:1) — This item applies only to trapezoidal and triangular channels. The user defines the ratio of Horizontal/Vertical by entering the number of horizontal units for one unit of vertical change.
• Channel Slope — Slope of the channel in m/m or ft/ft. If a zero slope is entered, an error message appears upon exiting the input data window. The user must enter a slope greater than zero before the crossing may be analyzed.
• Manning's n — User defined MANNING'S roughness coefficient for the channel.
• Channel Invert Elevation — User must enter the elevation of the channel at the culvert outlet. The program will show actual barrel #1 outlet invert elevation.