Q But
8.67 Because of a worn-out washer in a kitchen sink faucet, water drips at a steady rate even though the faucet is turned off. Readings from a water meter of the type shown in Video V8.7 indicate that during a one-week time period when the home owners were away, 200 gallons of water dripped from the faucet. a If the pressure within the 0.50-in-diameter pipe is 50 psi, determine the loss coefficient for the leaky faucet. b What length of the pipe would be needed to produce a head loss equivalent...
V Wqk
8.27 Water at 80 F flows in a 6-in.-diameter pipe with a flowrate of 2.0 cfs. What is the approximate velocity at a distance 2.0 in. away from the wall Determine the centerline velocity. 8.28 During a heavy rainstorm, water from a parking lot completely fills an 18-in.-diameter, smooth, concrete storm sewer. If the flowrate is 10 ft3 s, determine the pressure drop in a 100-ft horizontal section of the pipe. Repeat the problem if there is a 2-ft change in elevation of the pipe per 100 ft of its...
5n
An iterative scheme see solution of Eq. 6 in Example 8.10 to solve this equation for f gives f 0.027, and hence D 0.196 ft, in agreement with the Moody chart method. In the previous example we only had to consider major losses. In some instances the inclusion of major and minor losses can cause a slightly more lengthy solution procedure, even though the governing equations are essentially the same. This is illustrated in Example 8.13. FXAMPLE 8.13 TYPE III WITH MINOR LOSSES, DETERMINE DIAMETER...
Q Dae
Turbine-type flow meter. Courtesy of E G amp G Flow Technology, Inc. Turbine-type flow meter. Courtesy of E G amp G Flow Technology, Inc. Volume flow meters measure volume rather than volume flowrate. through the meter entering at the bottom , the float will rise within the tapered tube and reach an equilibrium height that is a function of the flowrate. This height corresponds to an equilibrium condition for which the net force on the float buoyancy, float weight, fluid drag is zero. A...
Q Mkk
8.14 For the flow discussed in Problem 8.13, plot the di-mensionless velocity profile u Vc, where Vc is the centerline velocity at r 0 , as a function of the dimensionless radial coordinate r D 2 , where D is the pipe diameter. Consider values of n 1, 3, 5, and 7. 8.15 A fluid of density p 1000 kg m3 and viscosity m 0.30 N s m2 flows steadily down a vertical 0.10-m-diameter pipe and exits as a free jet from the lower end. Determine the maximum pressure allowed in the pipe at a location 10 m...
847
Water flows at a rate of 0.040 m3 s in a 0.12-m-diameter pipe that contains a sudden contraction to a 0.06-m-diameter pipe. Determine the pressure drop across the contraction section. How much of this pressure difference is due to losses and how much is due to kinetic energy changes 8.48 A sign like the one shown in Fig. P8.48 is often attached to the side of a jet engine as a warning to airport workers. Based on Video V8.4 or Figs. 8.22 and 8.25, explain why the danger areas indicated in color...
Info Ihx
Although the governing pipe flow equations are quite simple, they can provide very reasonable results for a variety of applications, as is shown in the next example. FXAMPLE 8.9 TYPE I, DETERMINE HEAD LOSS Crude oil at 140 F with g 53.7 lb ft3 and m 8 x 105 lb s ft2 about four times the viscosity of water is pumped across Alaska through the Alaskan pipeline, a 799-mile-long, 4-ft-diameter steel pipe, at a maximum rate of Q 2.4 million barrels day 117 ft3 s, or V Q A 9.31 ft s. Determine the...
Xample 82
An oil with a viscosity of m 0.40 N s m2 and density p 900 kg m3 flows in a pipe of diameter D 0.020 m. a What pressure drop, p1 p2, is needed to produce a flowrate of Q 2.0 x 10 5 m3 s if the pipe is horizontal with x1 0 and x2 10 m b How steep a hill, U, must the pipe be on if the oil is to flow through the pipe at the same rate as in part a , but with p1 p2 c For the conditions of part b , if p1 200 kPa, what is the pressure at section x3 5 m, where x is measured along the pipe a If the...
Q Vkn
Pipe length 500 ft Pipe diameter 0.75 ft Pipe roughness 0 Pipe length 500 ft Pipe diameter 0.75 ft Pipe roughness 0 8.76 As shown in Video V8.6 and Fig. P8.76, water bubbles up 3 in. above the exit of the vertical pipe attached to three horizontal pipe segments. The total length of the 0.75-in.-diameter galvanized iron pipe between point 1 and the exit is 21 in. Determine the pressure needed at point 1 to produce this flow. 8.77 The pressure at section 2 shown in Fig. P8.77 is not to fall below...
Xample 85
Air under standard conditions flows through a 4.0-mm-diameter drawn tubing with an average velocity of V 50 m s For such conditions the flow would normally be turbulent. However, if precautions are taken to eliminate disturbances to the flow the entrance to the tube is very smooth, the air is dust free, the tube does not vibrate, etc. , it may be possible to maintain laminar flow. a Determine the pressure drop in a 0.1-m section of the tube if the flow is laminar. b Repeat the calculations if...
15
8.86 Water flows through a 2-in.-diameter pipe with a velocity of 15 ft s as shown in Fig. P8.86. The relative roughness of the pipe is 0.004, and the loss coefficient for the exit is 1.0. Determine the height, h, to which the water rises in the piezometer tube. 8.89 The pump shown in Fig. P8.89 adds 25 kW to the water and causes a flowrate of 0.04 m3 s. Determine the flowrate expected if the pump is removed from the system. Assume f 0.016 for either case and neglect minor losses.
854
duct with a flowrate of 8.2 cfs. Determine the pressure drop in inches of water per 200-ft length of duct. 8.58 Air flows through a rectangular galvanized iron duct of size 0.30 m by 0.15 m at a rate of 0.068 m3 s. Determine the head loss in 12 m of this duct. 8.59 Air at standard conditions flows through a horizontal 1 ft by 1.5 ft rectangular wooden duct at a rate of 5000 ft3 min. Determine the head loss, pressure drop, and power supplied by the fan to overcome the flow resistance in 500 ft...
With A Scale Reading Of 2.6 The Water Bubbles Up Approximately 3in.
8.110 Water flows through the Venturi meter shown in Fig. P8.110. The specific gravity of the manometer fluid is 1.52. Determine the flowrate. 8.103 Water is pumped from a lake, into a large pressurized tank, and out through two pipes as shown in Fig. P8.103. The pump head is hp 45 27.5Q 54Q2, where hp is in feet and Q the total flowrate through the pump is in ft3 s. Minor losses and gravity are negligible, and the friction factor in each pipe is 0.02. Determine the flowrates through each of...
1 Yhk
60 f 1 2, which can be combined with Eq. 3 to give The combination of Eqs. 4 and 5 provides a single equation for the determination of f 1 -2.0 log 4.05 x 10-4 4.39 x 105 A simple iterative solution of this equation gives f 0.029, in agreement with the above solution which used the Moody chart. This iterative solution using the Colebrook equation can be done as follows a assume a value of f, b calculate a new value by using the assumed value in the right-hand side of Eq. 6, c use this new f to...
References
1. Hinze, J. O., Turbulence, 2nd Ed., McGraw-Hill, New York, 1975. 2. Panton, R. L., Incompressible Flow, Wiley, New York, 1984. 3. Schlichting, H., Boundary Layer Theory, 7th Ed., McGraw-Hill, New York, 1979. 4. Gleick, J., Chaos Making a New Science, Viking Penguin, New York, 1987. 5. White, F. M., Fluid Mechanics, McGraw-Hill, New York, 1979. 6. Nikuradse, J., Stomungsgesetz in Rauhen Rohren, VDI-Forschungsch, No. 361, 1933 or see NACA Tech Memo 1922. 7. Moody, L. F., Friction Factors for...
90 Miter Bend With Vanes
FIGURE 8.29 Loss coefficient for a typical conical diffuser Ref. 5 . FIGURE 8.29 Loss coefficient for a typical conical diffuser Ref. 5 . Extensive tables are available for loss coefficients of standard pipe components. A2 A1, specific details of the geometry, and the Reynolds number. The data are often presented in terms of a pressure recovery coefficient, Cp p2 p1 pV 2 , which is the ratio of the static pressure rise across the diffuser to the inlet dynamic pressure. Considerable effort has...