Unformatted text preview: 12/13/2009 Exam 3 Review problems 057:020 Fall 2009 1. Head loss What level h must be maintained in Fig. P6.61 to deliver a flow rate of 0.015 ft3/s through the ½ ‐in commercial steel pipe? 2. Minor loss The water pipe in Fig. P6.106 slopes upward at 30°. The pipe has a 1‐in diameter and is smooth. The flanged globe valve is fully open. If the mercury manometer shows a 7‐in defection, what is the flow rate in ft3/s? 3. Lift and drag coefficient A heavy sphere attached to a strung should hang at an angel θ when immersed in a stream of velocity U, as in Fig. P7.80. Derive an expression for θ as a function of the sphere and flow properties. What is θ if the sphere is steel (SG = 7.86) of diameter 3 cm and the flow is sea‐level standard air at U =40 m/s? Neglect the string drag. 12/13/2009 Exam 3 Review problems 057:020 Fall 2009 4. Boundary layer A sharp flat plate with L = 50 cm and b = 3 m is parallel to a stream of velocity 2.5 m/s. Find the drag on one side of the plate, and the boundary thickness δ at the trailing edge for (a) air and (b) water at 20 °C and 1 atm. 5. Fluid kinematics Following the fluid particle, calculate the y component of acceleration for a particle whose velocity vector is given by V = (3z – x2)i + yt2j + xz2k in ft/sec at the point x = 1ft, y =1 ft, and t = 2sec. 6. Mass and momentum conservation A 45° reducing elbow can be found in domestic water piping system. As illustrated in Figure 3.15, water flows into the elbow in the positive direction and is deflected through an angle of 45°. The inlet diameter is 2.5 cm and the outlet diameter is 1.2 cm. The volume flow rate of water is 0.0008 m3/s. The inlet and outlet pressures are, respectively, 160 kPa and 150 kPa. If the elbow is located in a horizontal plane, determine the forces exerted on it by moving water. 12/13/2009 Exam 3 Review problems 057:020 Fall 2009 Solutions 1. 2. 12/13/2009 Exam 3 Review problems 057:020 Fall 2009 3. 4. 12/13/2009 Exam 3 Review problems 057:020 Fall 2009 5. 6. ...
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This note was uploaded on 12/08/2011 for the course MECHANICS 57:020 taught by Professor Fredrickstern during the Fall '10 term at University of Iowa.
 Fall '10
 FredrickStern

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