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Hydraulics II
Assignment II Page 1
HARAMAYA UNIVETITY
INSTITUTE OF TECNOLOGY
DEPARTMENT OF CIVIL AND URBAN ENGINEERING
1. A brick lined trapezoidal channel has side slopes of 1:1.5.
It is required to carry
15m3/s of water. If the average velocity of flow is not to
exceed 1 mls. Find.
(a ) the wetted perimeter for min: amount of lining ;
(b) bed slope assuming Manning's n = 0.015
2. Water is flowing in a rectangular channel with a velocity
of10 ft/sec, depth of 10ft
and a width of l0ft. If there is a smooth upward step of2ft in
the channel bed, what
expansion in width must simultaneously take place for the
up-stream flow to be
possible as specified?
3. Calculate the critical depth and the corresponding specific
energy for a discharge of5.0 m
3/sec in the following channels.
4. Calculate the critical depth and the corresponding specific
energy for a discharge of5.0 m
3/sec in the following channels.
a) Rectangular channel, B = 2.0 m.
b) Triangular channel, m = 0.5. c) Trapezoidal channel, B = 2.0
m, m = 1.5.
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Hydraulics II
Assignment II Page 2
5. A rectangular channel is 4m wide and the depth of water is
2m. If the slope is 1 in 1000,
determine without changing the water level at the entrance:
(a) the maximum height of the hump;(b) the minimum width of the
throat,
6. For a trapezoidal channel with base width b = 6.0 m and side
slope m = 2, calculate the
critical depth of flow if Q = 17 m3/s.
7. Given a trapezoidal channel with a bottom width of 3m, side
slope 1.5, a longitudinalslope of 0.0016 and estimated Mannings n
of 0.13, find the normal depth of flow for adischarge of
7.1m3/s.
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a) The upstream depth and velocity areh1 = 1m andV1 = 10m/s. Use
continuity
andmomentumconservation(withnofriction)tocalculatethedownstreamdepthandvelocity,h2
andV2.b)Fortheseflowconditions,calculatetheheadlossandtherateofenergydissipationinthehydraulicjump.c)Ifflowdirectionwaschanged,i.e.,ifflowwasfromrighttoleft,andyouknewh2
andV2tohavethevaluesobtainedina,showthath1 andV1
wouldalsohavethesamevaluesasina.d) Now, for the reversed flow (flow
fromright to left), what is the difference in total headbetween
inflow and outflow? What is the rate of energy dissipation? What is
wrong withthispicture?
Problem8Figurebelowshowsthephenomenonofhydraulicjumpinarectangularchannel,wherearatherabruptchangeoccursinthedepthoftheflow.
Figure: HydraulicjumpinProblem8.
