Unformatted text preview: e the water depth correlates with the flow
rate, is called a channel control point. These are the starting points for numerical analysis
of floodwater profiles in rivers as studied, e.g., by the U.S. Army Corps of Engineers .
EXAMPLE 10.10 | v v A rectangular channel 8 m wide, with a flow rate of 30 m3/s, encounters a 4-m-high sharp-edged
dam, as shown in Fig. E10.10a. Determine the water depth 2 km upstream if the channel slope
is S0 0.0004 and n 0.025. | e-Text Main Menu | Textbook Table of Contents | Study Guide Chapter 10 Open-Channel Flow H
(From weir theory) ter wa k
(M 1) c yn = 3.20 m
Y=4m Q = 30 m 3/s Q y?
Dam yc = 1.13 m X E10.10a S0 = 0.0004, b = 8 m
Manning's n = 0.025 x = – 2000 m x=0 Solution
First determine the head H produced by the dam, using sharp-crested full-width weir theory, Eq.
30 m3/s Q Cdbg1/2H3/2 0.564 0.0846 H
(8 m)(9.81 m/s2)1/2H3/2
4m Since the term 0.0846H/4 in parentheses is small, we may proceed by iteration or EES to the
solution H 1.59 m...
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