ID:‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Quiz: No. 7 Time: 15 minutes Name: ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Course: 58:160, Fall 2010 The exam is closed book and closed notes. Water at 10°C flows from a large reservoir to a smaller one through a 5-cmdiameter cast iron piping
system, as shown in the figure. Determine the elevation z1 for a flow rate of 0.006 m3/s. (pipe=0.00026 m;
water=1.307×10-3 kg/m.s; water=999.7 kg/m3)
Note that:
hl ,major  f
ii.
hl ,minor   K L
iii.
L V2
D 2g
i.
V2
2g
Va2
pb Vb2

z 

 z h h h
 2 g a  2 g b l turb pump
pa
ID:‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Quiz: No. 7 Time: 15 minutes Name: ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Course: 58:160, Fall 2010 ID:‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Quiz: No. 7 Time: 15 minutes Name: ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Course: 58:160, Fall 2010 Solution:
p1


V12
p V2
 z1  2  2  z2  hl (1 point) 2g
 2g
p1  p2  patm (1 point)
V1  V2  0 (1 point) 2
hl  hl ,major  hl ,minor
V
L
 ( f   K L ) pipe (1 point) 2g
D
2
V
L
  K L ) pipe
2g
D
Q
0.006
 3.06 m / s (1 point)
V pipe  
A  (0.05) 2 / 4
V pipe D (999.7)(3.06)(0.05)

 117000  4000 Turbulent (1 point)
Re 

1.307 103
 0.00026

 0.0052 (1 point)
D
0.05
 z1  z2  ( f
 f  F (Re,  / D)  0.0315 Moody
Chart (2 point) 2
 z1  z2  ( f
V
L
  K L ) pipe
D
2g
 4  (0.0315
 4  27.9
 31.9
89
3.062
(1 point)
 2.36)
0.05
2(9.81)