CIV E 530 - OPEN-CHANNEL HYDRAULICS
SPRING 2006
HOMEWORK No. 4

  1. Using the theory of critical flow, calculate the discharge (in m3 s-1) over a broad crested weir of length L = 8.5 m, when the total head above the weir crest is H = 0.25 m. Assume negligible approach velocity. Recalculate with L = 24 ft and H = 0.8 ft. Verify using onlinechannel14.php in onlinechannel.sdsu.edu. Show hand calculations and output from onlinechannel14.php

  2. Compute critical depth and velocity for the following cases, using CHANNEL in onlinecomp.sdsu.edu.

    a. Q = 500 m3/sec, B = 75 m, z = 1
    b. Q = 1000 cfs, B = 40 ft, z = 1.5
    c. Q = 1500 m3/sec, B = 145 m, z = 2
    d. Q = 2000 cfs, B = 120 ft, z = 1

    Assume suitable values of bottom slope and Manning's n. Show output from CHANNEL.

  3. What is the slope that will produce critical flow in a rectangular channel with Q = 12 m3/sec, B = 2.8 m, and n = 0.020? Use trial and error with CHANNEL in onlinecomp.sdsu.edu. Show final output from CHANNEL. Use three significant digits for answer.