Unformatted text preview: Re2 V3
4
Re1
3 2
d1
2 V1
d3 4V1 Re3 2 Re1 Neglecting minor losses and substituting into Eq. (6.107), we obtain
2
V1
1250 f1
2g hA→B
or 2500 2
V1
(1250 f1
2g 20.3 m 16
9 2 2000(4)2 f3 f2 7900 f2 32,000 f3) (1) This is the form which was hinted at in Eq. (6.108). It seems to be dominated by the third pipe
loss 32,000f3. Begin by estimating f1, f2, and f3 from the Moodychart fully rough regime
f1 0.0262 2
Substitute in Eq. (1) to find V 1
0.58 m/s, from which Re1 f2 0.0234 2g(20.3)/(33 45,400 Re2 185 60,500 f3 0.0304 973). The first estimate thus is V1
Re3 90,800 Hence, from the Moody chart,
f1 0.0288 f2 0.0260 f3 0.0314 2.84 10 Substitution into Eq. (1) gives the better estimate
V1 0.565 m/s Q or Q1 A second iteration gives Q 1
4 2
d 1V1 3 m3/s 10.2 m3/h Ans. 3 10.22 m /h, a negligible change.  v v The second multiplepipe system is the parallelflow case shown in Fig. 6.24b. Here
the loss is the same in each pipe, and the total flow is the sum of the individual flows  eText Main Menu  Textbook Table of Contents  Study Guide 378 Chapter 6 Viscous Flow in Ducts hA→B
Q h1
Q1 h2
Q2 h...
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This note was uploaded on 10/27/2009 for the course MAE 101a taught by Professor Sakar during the Spring '08 term at UCSD.
 Spring '08
 Sakar

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