3_Hydraulics Practice Quiz with Answer and Solution

Refresher - HYDRAULICS Quiz 3
PROBLEM 1-3:

In the figure shown, reservoir A is the source of water supply and is at elevation 150 m, B is
the junction at elevation 91.46 m, C is a town at elevation 30.49 m. with 25000 inhabitants,
D is another town at elevation 15.24 m. with a population of 30000 inhabitants. Length
AB = 15,240 m, BC is 9150 m, BD = 6100 m. Determine the size of the pipes if the
consumption is 150 liters per capita per day. For the pipes, friction factor f = 0.02.
El. 150 m

➀ Determine the required diameter of pipe AB. A
➁ Determine the required diameter of pipe BC.
➂ Determine the required diameter of pipe BD.
B El. 91.46 m
Solution: Population = 25000
El. 30.49 m
➀ Diameter of pipe AB C
150(30000) El. 15.24 m

Q3 = D Population = 30000
24(3600)(1000)
Q 3 = 0.052 m3 /sec.
150(25000)
Q2 =
24(3600)(1000) El. 150 m

A
Q 2 = 0.0434 m3 /sec.
1 hf1
Q1 = Q 2 + Q 3
Q1 = 0.052 + 0.0434 B El. 91.46 m

3
2
h f2
Q1 = 0.0954 m /s h f3 3
El. 30.49 m

C
2
0.0826fLQ El. 15.24 m
hf1 = 1
D
D15
hf1 = 150 - 91.46
hf1 = 58.54 m
0.0826(0.02)(15240)(0.0954)2
58.54 =
D15
D1 = 0.33 m

, Refresher - HYDRAULICS Quiz 3
PROBLEM 1-3: cont.


➁ Diameter of pipe BC
hf2 = 91.46 - 30.49
hf2 = 60.97
0.0826fLQ 22
hf2 =
D52
0.0826(0.02)(9150)(0.0434)2
60.97 =
D52
D2 = 0.216 m


➂ Diameter of pipe BD
hf3 = 91.46 - 15.24
hf3 = 76.22
0.0826fLQ 23
hf3 =
D53
0.0826(0.02)(6100)(0.052)2
76.22 =
D53
D3 = 0.204 m