CE530- OPEN CHANNEL HYDRAULICS
SPRING 2008
SECOND MIDTERM
WEDNESDAY, MARCH 26, 2008, 1600-1715
Name: ___________________________ Red ID No. __________________ Grade: ________
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Instructions: Closed book, closed notes. Use engineering paper.
When you are finished, staple your work in sequence (1 to 4),
and return this sheet with your work.
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(25%) What is the discharge in a rectangular channel of bottom width b = 5 m, bed slope So = 0.003, Manning's
n= 0.015, and flow depth y = 1.5 m?
- (25%) A weir is located at the downstream end of a wide rectangular channel of bottom slope
So = 0.004 and (dimensionless Chezy) friction factor f = 0.004.
The unit-width discharge in the wide rectangular channel is 2 m3/s/m.
Immediately upstream of the weir, the flow is subcritical, with depth 3 m.
- Calculate the upstream Froude number.
- Calculate the upstream flow depth.
- Calculate the usptream flow velocity.
- What is the type of water-surface profile?
- Provide a quick estimate of the length of the water-surface profile.
- (25%) Please answer the following questions in a brief statement.
- Who was Manning?
- What is "hungry water"?
- How many types of water surface profiles (WSP) are there in gradually varied flow (GVF)?
Which water surface profiles are completely horizontal?
- In gradually varied flow in a hydraulically wide channel, the flow depth gradient Sy is a function of three (geometric and physical)
parameters. What are these?
- What are the five characteristic values to which the flow depth gradient Sy tends in WSP computations?
- (25%) Do a tabular comparison between the direct-step and standard-step methods of steady gradually varied flow computation.
State at least eight differences.
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