CIV E 530 - OPEN-CHANNEL HYDRAULICS

SPRING 2017 - MIDTERM 2 - SOLUTION

PROBLEM 2

    • Find the upstream Froude number:

      f = Sc = So  (downstream) = 0.004

      So = Sc F12

      F12 = So / Sc = 0.025 / 0.004 = 6.25

      F1 = 2.5   ANSWER.

    • Find the upstream flow depth:

      F12 = v2/(gy1) = q2/(gy13) = 6.25

      y1 = [q2/(6.25 g)]1/3 = [(2.2)2 /6.25 × 9.81)]1/3 = 0.429 m.    ANSWER.

    • Find the downstream flow depth:

      F22 = v2/(gy2) = q2/(gy23) = 1

      y2 = [q2/g]1/3 = [(2.2)2 / 9.81]1/3 = 0.790 m.    ANSWER.

    • So = Δy/Δx

      Δx = Δy / So = (y2 - y1) / So = (0.790 - 0.429) / 0.004

      Δx = 90.25 m.   ANSWER.

Problem 3

 
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