SPRING 2014
FIRST MIDTERM
MONDAY, FEBRUARY 24, 2014, 1600-1650
Name: __________________ Red ID ____________________ Grade:____ _________
- (30%) A high overflow spillway has a downstream slope after the point of tangency
of 0.6 H to 1 V (see figure). The Darcy-Weisbach friction factor of smooth concrete
is fD = 0.032.
What is the prevailing Froude number right after the point of tangency? What is your estimate
of the maximum value of Froude number that can be achieved in practice?
- (20%)
On July 31, 1976, the Big Thompson Canyon, near Loveland, Colorado, experienced a record flood event.
Peak flood depths were estimated at 20 ft. The average width of the canyon is 61.5 ft.
Assume critical flow prevailed during the passage of the flood.
Provide an estimate of the peak discharge.
- (20%) The overflow spillway at Turner reservoir, in San Diego County, is 8 ft wide. On February 24, 2005, after several days of heavy rain, the head over the spillway was 3 in. The discharge coefficient at the weir has been calibrated to be C = 3.0 What is the discharge?
- (30%) Please answer the following questions in a brief statement.
- Why is unsteady uniform flow not possible in practice?
- What four forces are used in open-channel flow analysis?
- What width/depth ratio will assure hydraulically wide conditions in an open channel?
- What is the neutral-stability Froude number in a wide rectangular channel with Chezy friction?
- What is the maximum value of Manning's n encountered in practice? Where does it apply?
- What is the difference between Seddon waves and Lagrange waves? What do they have in common?
- (20%) The overflow spillway at Turner reservoir, in San Diego County, is 8 ft wide. On February 24, 2005, after several days of heavy rain, the head over the spillway was 3 in. The discharge coefficient at the weir has been calibrated to be C = 3.0 What is the discharge?