Fluid Mechanics Fundamentals And Applications
3rd Edition
ISBN: 9780073380322
Author: Yunus Cengel, John Cimbala
Publisher: MCGRAW-HILL HIGHER EDUCATION
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Chapter 5, Problem 145P
Computer-aided designs, the use of better materials, and better manufacturing techniques have resulted in a tremendous increase in the efficiency of pumps, turbines, and electric motors. Contact one or more pump, turbine, and motor manufacturers and obtain information about the efficiency of their products. In general, how does efficiency vary with rated power of these devices?
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Chapter 5 Solutions
Fluid Mechanics Fundamentals And Applications
Ch. 5 - Name four physical quantities that are conserved...Ch. 5 - Define mass and volume flow rates. How are they...Ch. 5 - Does the amount of mass entering a control volume...Ch. 5 - When is the flow through a control volume steady?Ch. 5 - Consider a device with one inlet and one outlet....Ch. 5 - In climates with low night-time temperatures, an...Ch. 5 - A garden hose attached with a nozzle is used to...Ch. 5 - Air whose density is 0.082 Ibm/ft3 enters the duct...Ch. 5 - A 0.7$-m3 rigid tank initially contains air whose...Ch. 5 - Consider the flow of an incompressible Newtonian...
Ch. 5 - Consider a fully filled tank of semi-circular...Ch. 5 - Prob. 12PCh. 5 - Prob. 13PCh. 5 - The minimum fresh air requirement of a residential...Ch. 5 - Air enters a nozzle steadily at 2.21 kg/m3 and 20...Ch. 5 - Air at 40°C flow steadily through the pipe shown...Ch. 5 - A hair dryer is basically a duct of constant...Ch. 5 - Define turbine efficiency, generator efficiency,...Ch. 5 - What is mechanical efficiency? What does a...Ch. 5 - How is the combined pump-motor efficiency of a...Ch. 5 - What is mechanical energy? How does it differ from...Ch. 5 - Prob. 22PCh. 5 - A differential thermocouple with sensors at the...Ch. 5 - Electric power is to be generated by installing a...Ch. 5 - Consider a river flowing toward a lake at an...Ch. 5 - Water is pumped from a lake to a storage tank 18 m...Ch. 5 - Prob. 28CPCh. 5 - Express the Bernoulli equation in three different...Ch. 5 - What are the three major assumptions used in the...Ch. 5 - Define static, dynamic, and hydrostatic pressure....Ch. 5 - What is streamwise acceleration? How does it...Ch. 5 - What is stagnation pressure? Explain how it can be...Ch. 5 - Prob. 34CPCh. 5 - How is the location of the hydraulic grade line...Ch. 5 - Prob. 36CPCh. 5 - What is the hydraulic grade line? How does it...Ch. 5 - A glass manometer with oil as the working fluid is...Ch. 5 - The velocity of a fluid flowing in a pipe is to be...Ch. 5 - The water level of a tank on a building roof is 20...Ch. 5 - Prob. 41CPCh. 5 - In a hydroelectric power plant, water enters the...Ch. 5 - A Pitot-static probe is used to measure the speed...Ch. 5 - The air velocity in the duct of a heating system...Ch. 5 - Prob. 45EPCh. 5 - A piezometer and a Pitot tube are tapped into a...Ch. 5 - The diameter of a cylindrical water tank is D0and...Ch. 5 - A siphon pumps water from a large reservoir to a...Ch. 5 - Prob. 49PCh. 5 - Water flows through a horizontal pipe at a rate of...Ch. 5 - An airplane is flying at an altitude of 10.500 m....Ch. 5 - While traveling on a dirt road, the bottom of a...Ch. 5 - The water in an 8-rn-diameter, 3-rn-high...Ch. 5 - Reconsider Prob. 5-49. Determine how long it will...Ch. 5 - Air at 105 kPa and 37°C flows upward through a...Ch. 5 - A handheld bicycle pump can be used as an atomizer...Ch. 5 - Water at 20°C is siphoned from a reservoir as...Ch. 5 - The water pressure in the mains of a city at a...Ch. 5 - A pressurized tank of water has a 10-cm-diameter...Ch. 5 - Air is flowing through a venturi meter whose...Ch. 5 - The water level in a tank is 15 m above the...Ch. 5 - A Pilot-static probe connected to a water...Ch. 5 - The air velocity in a duct is measured by a...Ch. 5 - In cold climates, water pipes may freeze and burst...Ch. 5 - A well-fitting piston with 4 small holes in a...Ch. 5 - A fluid of density and viscosity flows through a...Ch. 5 - What is useful pump head? How is it related to the...Ch. 5 - Consider the steady adiabatic flow of an...Ch. 5 - What is irreversible head loss? How is it related...Ch. 5 - Consider the steady adiabatic flow of an...Ch. 5 - What is the kinetic energy correction factor? Is...Ch. 5 - The water level in a tank is 20 m above the...Ch. 5 - A person is filling a knee-high bucket with water...Ch. 5 - A 3-rn-high tank filled with water has a discharge...Ch. 5 - In a hydroelectric power plant, water flows from...Ch. 5 - Reconsider Prob. 5-78E. Determine the flow rate of...Ch. 5 - An oil pump is drawing 25 kW of electric power...Ch. 5 - Tater is being pumped from a large lake to a...Ch. 5 - A 15-hp (shaft) pump is used to raise water to a...Ch. 5 - Water flows at a rate of 0.035 m3/s in a...Ch. 5 - The water level in a tank is 20 m above the...Ch. 5 - A hydraulic turbine has 50 m of head available at...Ch. 5 - A fan is to be selected to ventilate a bathroom...Ch. 5 - Water flows at a rate of 20 L/s through a...Ch. 5 - The water level in a tank is 34 ft above the...Ch. 5 - A large tank is initially filled with water 5 m...Ch. 5 - Water enters a hydraulic turbine through a...Ch. 5 - The velocity profile for turbulent flow in a...Ch. 5 - Water is pumped from a lower reservoir to a higher...Ch. 5 - Water in a partially filled large tank is to be...Ch. 5 - Underground water is to be pumped by a 78 percent...Ch. 5 - Reconsider Prob. 5-88. Determine the flow rate of...Ch. 5 - A 78-percent efficient 12-hp pump is pumping water...Ch. 5 - The demand for electric power is usually much...Ch. 5 - When a system is subjected to a linear rigid body...Ch. 5 - A fireboat is to fight fires at coastal areas by...Ch. 5 - The velocity of a liquid flowing in a circular...Ch. 5 - Air at 250 kgrn3 enters a nozzle that has an...Ch. 5 - The water level in a tank is 70 ft above the...Ch. 5 - A pressurized 2-rn-diameter tank of water has a...Ch. 5 - Air flows through a pipe at a rate of 120 L/s. The...Ch. 5 - A very large tank contains air at 102 kPa at a...Ch. 5 - Water is flowing through a Venturi meter whose...Ch. 5 - Water flows at a rate of 0.011 m3/s in a...Ch. 5 - The air in a 6-m × 5-m × 4-m hospital room is to...Ch. 5 - Underground water is being pumped into a pool...Ch. 5 - A 3-rn-high large tank is initially filled with...Ch. 5 - Reconsider Prob. 5-105. In order to dram the tank...Ch. 5 - A D0=8 -m-diameter tank is initially filled with...Ch. 5 - In some applications, elbow-type flow meters like...Ch. 5 - The cylindrical water tank with a valve at the...Ch. 5 - A rigid tank of volume 1.5 m3 initially contains...Ch. 5 - A wind tunnel draws atmospheric air at 20°C and...Ch. 5 - Water flows in a 5-cm-diameter pipe at a velocity...Ch. 5 - Air at 100 kPa and 20°C flows in a 12-cm-diameter...Ch. 5 - A water tank initially contains 140 L of water....Ch. 5 - Water enters a 4-cm-diameter pipe at a velocity of...Ch. 5 - The pressure of water is increased from 100 kPa to...Ch. 5 - A 75-m-high water body that is open to the...Ch. 5 - A pump is used to increase the pressure of water...Ch. 5 - A hydraulic turbine is used to generate power by...Ch. 5 - The motor of a pump consumes 1.05 hp of...Ch. 5 - The efficiency of a hydraulic turbine-generator...Ch. 5 - Which parameter is not related in the Bernoulli...Ch. 5 - Consider incompressible, frictionless flow of a...Ch. 5 - Consider incompressible, frictionless flow of...Ch. 5 - Consider water flow in a piping network. The...Ch. 5 - The static and stagnation pressures of a fluid in...Ch. 5 - The static and stagnation pressures of a fluid in...Ch. 5 - The difference between the heights of energy grade...Ch. 5 - Water at 120 kPa (gage) is flowing in a horizontal...Ch. 5 - Water is withdrawn a the bottom of a large tank...Ch. 5 - Water at 80 kPa (gage) enters a horizontal pipe at...Ch. 5 - Seawater is to be pumped into a large tank at a...Ch. 5 - Water enters a pump at 350 kPa at a rate of 1...Ch. 5 - An adiabatic pump is used to increase the pressure...Ch. 5 - The shaft power from a 90 percent-efficient...Ch. 5 - Using a 1are bucket whose volume is known and...Ch. 5 - Your company is setting up an experiment that...Ch. 5 - Computer-aided designs, the use of better...Ch. 5 - Using a handheld bicycle pump to generate an air...Ch. 5 - Using a flexible drinking straw and a ruler,...Ch. 5 - The power generated by a wind turbine is...
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- Hydro-machinery such as turbines and pumps represent fluid devices that have wide variety of configurations. Centrifugal pumps add energy to a fluid – by doing work on the fluid to move and increase the pressure. Figure 3 below shows the velocity diagram at the inlet and exit of a centrifugal pump impeller pumping water at 6000 L/min and operating at 1750 rpm. The pump has a blade height, b, of 6cm with ri = 4cm and r2 = 16cm, with an exit blade angle B2 = 22°. Assume ideal flow conditions and that the tangentia! velocity component of the water entering the blade is zero. Analyze the pump in terms of tangential velocity component at the exit Ve2, the ideal head W shaft rise hi, and the power transferred to the fluid Jaz V Figure 3arrow_forwardFor each statement, choose whether the statement is true or false, and discuss your answer briefly: (a) If the rpm of a pump is doubled, all else staying the same, the capacity of the pump goes up by a factor of about 2. (b) If the rpm of a pump is doubled, all else staying the same, the net head of the pump goes up by a factor of about 2. (c) If the rpm of a pump is doubled, all else staying the same, the required shaft power goes up by a factor of about 4. (d) If the rpm of a turbine is doubled, all else staying the same, the output shaft power of the turbine goes up by a factor of about 8.arrow_forwardGive at least two reasons why turbines often have greater efficiencies than do pumps.arrow_forward
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