ME 460 (Bittle) Spring 2016
HW #4
Fluids/Piping Systems Review
Your submission should be well organized and neatly written as if it was a solution manual. Work
problems by scratch first then rewrite solution for submission. In parts done using excel only the results
need to be provided.
1. A hydraulic turbine requires 2,000 gpm flow through a 10,000-ft-long pipe. The available head is
1000 ft-lbf/lbm. The pipe is to be schedule 40 commercial steel and a gate valve (K = 0.17 fully
open) is available for flow control.
a. Find the minimum standard pipe diameter required. (By hand for 1st guess of Diameter,
show work) Use Appendix C or online resource for standard ANSI pipe sizes.
b. Only using the required head for the pipe size in part a) and for a gate-valve setting of
3/4, 1/2, 1/4, 1/8, and 1/16 open, find the resulting flow rate. Use Figure 1-8 for gate
valve losses with now known pipe size from part a).
c. Plot the results of part (b) as flow rate versus valve position. (Print Plot and add
appropriate axis labels, like for a formal report)
d. What does part (c) say about control of low flow rates through this pipe?
e. What is the K value for a closed valve?
Copy plot into word and include discussion of part d and e below the figure.
2. A pump moves 0.4 ft3/s of light oil through a 2-in. ID, cast-iron line 500 ft long, as shown below.
NOTE: Pressure in left tank is not ambient. Assume elbow has a radius of 6-in. And the added
globe valve is half open. Use Figure 1-8 for K factors.
a. Determine the pumping power required, in hp. (by hand, confirm in excel)
b. What is power required if oil is heated such that mu = 1.6E-3 lbm/ft-s? (use excel)
c. How much heat energy in hp (odd units) is required to heat the oil to the temperature
required to get mu from part b. (by hand) NOTE: you must find temperature required by
interpolation. Compare this to pumping work saved from a to b.
d. For conditions of part a, what would flow rate, in ft3/s, be if the pump delivered 5 hp to
the fluid?
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