CIV E 530 - OPEN-CHANNEL HYDRAULICS
SPRING 2007
HOMEWORK No. 2

  1. Given a trapezoidal channel with bottom width b, flow depth y, and side slope z (z horizontal to 1 vertical).

    • Develop a general formula for flow area and wetted perimeter as a function of bottom width, flow depth, and side slope.

    • Develop a spreadsheet to calculate, in 5% increments of flow depth, the following variables: relative depth, depth, flow area, wetted perimeter, hydraulic radius, top width, and hydraulic depth.

    • Test your work with the following data sets:

      Shape Bottom width
      (m)      		 Flow depth
      (m)      		 Side slope z
      (z H : 1 V)
      Trapezoidal 12 2 1.5
      Rectangular 6 1.5 0
      Triangular 0 1 2

     

  2. Given the following data measured in a cross section in an open channel, calculate the velocity distribution coefficients α and β.

    Element Flow
    velocity
    (m/s)    		 Incremental
    flow area
    (m2)
    1 3.0 52.0
    2 2.5 45.3
    3 2.0 63.2
    4 1.5 75.2
    5 1.2 81.7
    6 1.0 92.3