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CE 4353/5360 Design of Hydraulic Systems
Fall 2022 Exercise Set 7

LAST NAME, FIRST NAME

R00000000

Purpose :

Apply principles of uniform flow to open channel analysis and design

Assessment Criteria :

Completion, results plausible, format correct, calculations (Jupyter Notebook) are shown.

Problem 1

A trapezoidal roadside drainage ditch with a design discharge of 3.75 $\frac{m3}{s}$ is lined with grass having a retardance of class C. The slope of the ditch is 0.004 and it has a bottom width of 2.0 m with side slopes of 3:1.

Determine:

  • Determine the design depth of flow
  • Whether the channel is stable

Solution

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# sketch(s) here
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# list known quantities
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# list unknown quantities
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# governing principles
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# solution (step-by-step/computations)
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# discussion

Problem 2

Design a riprap-lined trapezoidal channel that has a capacity of 1000 cfs and a slope of 0.0005 ft/ft. Crushed rock is to be used and the channel bottom width is not to exceed 15 ft.

Determine:

  • The riprap size.
  • The side slopes.
  • The design depth of flow.

Solution

In [ ]:
# sketch(s) here
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# list known quantities/inputs
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# list unknown quantities/outputs
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# governing principles/algorithms used
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# solution (step-by-step/computations)
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# discussion

Problem 3

A rectangular channel has a width of 10 ft and a Manning's n value of 0.020. Determine

Determine:

  • The channel slope such that uniform flow will always have a Froude number less than or equal to 0.5 regardless of the discharge.

Solution

Problem 4

Figure 4 is a compound channel which has symmetric floodplains, each of which is 100 m wide with Manning's n = 0.06, and a main channel, which is trapezoidal with a bottom width of 10 m, side slopes of 1.5:1, a bank-full depth of 2.5 m, and a Manning’s n of 0.03. The channel longitudinal slope is 0.001 and the total depth is 3.7 m

Figure 4. Engineered channel cross section

Determine:

  • The uniform flow discharge using the divided channel method with vertical interfaces separating the main channel from the overbank areas and including these in the wetted perimeters
  • The uniform flow discharge using the divided channel method with vertical interfaces separating the main channel from the overbank areas without including these in the wetted perimeters
  • The uniform flow discharge using the divided channel method using the diagonal interface approach to separate the flow areas, but don’t use the diagonal interfaces in the wetted perimeters.

Solution

In [ ]:
# sketch(s) here
In [ ]:
# list known quantities
In [ ]:
# list unknown quantities
In [ ]:
# governing principles
In [ ]:
# solution (step-by-step/computations)
In [ ]:
# discussion