CIV E 530 - OPEN-CHANNEL HYDRAULICS

FALL 2008 - MIDTERM 2 - SOLUTION

PROBLEM 3: ESSAY QUESTIONS

1.

    Free board is the vertical distance from the top of the channel to the water surface at the design condition.

2.

    Free board can be used sometimes to accomodate the Probable Maximum Flood.

3.

    The channel side angle φ, and the angle of repose θ.

4.

    A water is "hungry" when it has less sediment that it can transport. Therefore, it has the tendency to entrain sediment until it reaches an equilibrium or steady load.

5.

    12 types.
6.
    The profiles C1 and C3 are completely horizontal.

7.

    So (gravity), Sc (friction), and Froude number (hydraulics).

8.

    The labyrinth spillway increases the size of the spillway length (L). Therefore, it increases the discharge through the spillway.

9.

    Because it may lead to cavitation and consequent structural damage.

10.

    According to Chow, the maximum Froude number in a hydraulic jump is F = 20.
Problem 4

 
080318