This program calculates the spillway discharge at different water elevations. As the water elevation initially rises above the riser, the flow is controlled by weir flow. At higher water elevations the flow is under orifice control. When the barrel flows full, the flow is controlled by full pipe flow. Given the water elevation and spillway dimensions, the program calculates the type of flow and discharge.
The Calculate button will read the values in the dialog, calculate the flow and report this flow value at the bottom of the dialog. The Report button will generate a report of the input values and calculated flows. The File routine will create a stage-discharge (.STG) file. The Draw function will draw and label the drop pipe spillway in the drawing at the specified scale. The Graph button creates a stage-discharge graph.
Data:
Pool elevation:............. = 976.00 ft
Top of riser elevation:..... = 975.20 ft
Bottom of riser elevation:.. = 973.00 ft
Outlet elevation:........... = 968.00 ft
Diameter of riser pipe:..... = 20.00 in
Diameter of culvert pipe:... = 30.00 in
Length of culvert:.......... = 145.00 ft
Entrance loss coefficient:.. = 2.1600
Friction coefficient:....... = 0.0220
Weir coefficient:........... = 3.3000
Orifice coefficient:........ = 0.9500
Spillway discharge:
Weir Flow Discharge......... = 12.36 CFS
Orifice Flow Discharge...... = 14.87 CFS
Full Pipe Flow Discharge.... = 23.50 CFS
Spillway discharge.......... = 12.36 CFS
Pulldown Menu Location: Structure
in Hydrology
Keyboard Command: spillway
Prerequisite: None
File Name: \lsp\spillway.lsp