Sketched in Fig. P12.10 are the upstream [section (1)] and

For a turbomachine pump, such as a window fan or a propeller, a) rotation of the fan or propeller results in movement of fluid. b) rotation of the fan or propeller results in energy being transferred to the fluid. c) rotation of the fan or propeller requires work input to the fan or propeller shaft. d) All of the above.

A purpose of a water pump is to turn the pump shaft work into an increase in a) the pressure of the fluid. b) the volume of the fluid. c) the density of the fluid. d) the enthalpy of the fluid.

When wind is acting on a windmill, the power produced will depend on a) the velocity of the wind relative to the blade. b) the velocity of the blade relative to the ground. c) the velocity of the ground relative to the blade. d) the velocity of the wind relative to the ground.

The rotor shown in Fig. P12.1 rotates clockwise. Assume that the fluid enters in the radial direction and the relative velocity is tangent to the blades and remains constant across the entire rotor. Is the device a pump or a turbine? Explain.

Air (assumed incompressible) flows across the rotor shown in Fig. P12.2 such that the magnitude of the absolute velocity increases from 15 m/s to 25 m/s. Measurements indicate that the absolute velocity at the inlet is in the direction shown. Determine the direction of the absolute velocity at the outlet if the fluid puts no torque on the rotor. Is the rotation CW or CCW? Is this device a pump or a turbine?

The measured shaft torque on the turbomachine shown in Fig. P12.3 is \(-60~\mathrm{ N \cdot m}\) when the absolute velocities are as indicated. Determine the mass flowrate. What is the angular velocity if the magnitude of the shaft power is \(1800 ~\mathrm{N \cdot m/s}\)? Is this machine a pump or a turbine? Explain.

Water flows through a rotating sprinkler arm as shown in Fig. P12.4 and Video V12.2. Estimate the minimum water pressure necessary for an angular velocity of 150 rpm. Is this a turbine or a pump?

Water is supplied to a dishwasher through the manifold shown in Fig. P12.5. Determine the rotational speed of the manifold if bearing friction and air resistance are neglected. The total flowrate of 2.3 gpm is divided evenly among the six outlets, each of which produces a 5/16-in.-diameter stream.

Water flows axially up the shaft and out through the two sprinkler arms as sketched in Fig. P12.4 and as shown in Video V12.2. With the help of the moment-of-momentum equation explain why only at a threshold amount of water flow, the sprinkler arms begin to rotate. What happens when the flowrate increases above this threshold amount? If the exit nozzle could be varied, what would happen for a set flowrate above the threshold amount, when the angle is increased to \(90^\circ\)? Decreased to \(0^\circ\)?

Uniform horizontal sheets of water of 3-mm thickness issue from the slits on the rotating manifold shown in Fig. P12.7. The velocity relative to the arm is a constant 3 m/s along each slit. Determine the torque needed to hold the manifold stationary. What would the angular velocity of the manifold be if the resisting torque is negligible?

At a given radial location, a 15-mph wind against a windmill (see Video V12.1) results in the upstream (1) and downstream (2) velocity triangles shown in Fig. P12.8. Sketch an appropriate blade section at that radial location and determine the energy transferred per unit mass of fluid.

Sketch how you would arrange four 3-in.-wide by 12-in.-long thin but rigid strips of sheet metal on a hub to create a windmill like the one shown in Video V12.1. Discuss, with the help of velocity triangles, how you would arrange each blade on the hub and how you would orient your windmill in the wind.

Sketched in Fig. P12.10 are the upstream [section (1)] and downstream [section (2)] velocity triangles at the arithmetic mean radius for flow through an axial-flow turbomachine rotor. The axial component of velocity is 50 ft/s at sections (1) and (2). (a) Label each velocity vector appropriately. Use V for absolute velocity, W for relative velocity, and U for blade velocity. (b) Are you dealing with a turbine or a fan? (c) Calculate the work per unit mass involved. (d) Sketch a reasonable blade section. Do you think that the actual blade exit angle will need to be less or greater than \(15^\circ\)? Why?

Shown in Fig. P12.11 is a toy “helicopter” powered by air escaping from a balloon. The air from the balloon flows radially through each of the three propeller blades and out small nozzles at the tips of the blades. The nozzles (along with the rotating propeller blades) are tilted at a small angle as indicated. Sketch the velocity triangle (i.e., blade, absolute, and relative velocities) for the flow from the nozzles. Explain why this toy tends to move upward. Is this a turbine? Pump?

The radial component of velocity of water leaving the centrifugal pump sketched in Fig. P12.12 is 45 ft/s. The magnitude of the absolute velocity at the pump exit is 90 ft/s. The fluid enters the pump rotor radially. Calculate the shaft work required per unit mass flowing through the pump.

A centrifugal water pump having an impeller diameter of 0.5 m operates at 900 rpm. The water enters the pump parallel to the pump shaft. If the exit blade angle, \(\beta_2\) (see Fig. 12.8), is \(25^\circ\), determine the shaft power required to turn the impeller when the flow through the pump is \(\mathrm{0.16 ~m^3 /s}\). The uniform blade height is 50 mm.

A centrifugal pump impeller is rotating at 1200 rpm in the direction shown in Fig. P12.14. The flow enters parallel to the axis of rotation and leaves at an angle of \(30^\circ\) to the radial direction. The absolute exit velocity, \(V_2\), is 90 ft/s. (a) Draw the velocity triangle for the impeller exit flow. (b) Estimate the torque necessary to turn the impeller if the fluid is water. What will the impeller rotation speed become if the shaft breaks?

A centrifugal radial water pump has the dimensions shown in Fig. P12.15. The volume rate of flow is \(0.25~\mathrm{ ft^3 /s}\), and the absolute inlet velocity is directed radially outward. The angular velocity of the impeller is 960 rpm. The exit velocity as seen from a coordinate system attached to the impeller can be assumed to be tangent to the vane at its trailing edge. Calculate the power required to drive the pump.

Water is pumped with a centrifugal pump, and measurements made on the pump indicate that for a flowrate of 240 gpm the required input power is 6 hp. For a pump efficiency of 62%, what is the actual head rise of the water being pumped?

The performance characteristics of a certain centrifugal pump are determined from an experimental setup similar to that shown in Fig. 12.10. When the flowrate of a liquid (SG = 0.9) through the pump is 120 gpm, the pressure gage at (1) indicates a vacuum of 95 mm of mercury and the pressure gage at (2) indicates a pressure of 80 kPa. The diameter of the pipe at the inlet is 110 mm and at the exit it is 55 mm. If \(z_2 - z_1 = 0.5~\mathrm{m}\), what is the actual head rise across the pump? Explain how you would estimate the pump motor power requirement.

The performance characteristics of a certain centrifugal pump having a 9-in.-diameter impeller and operating at 1750 rpm are determined using an experimental setup similar to that shown in Fig. 12.10. The following data were obtained during a series of tests in which \(z_2 - z_1 = 0, V_2 = V_1\), and the fluid was water. Based on these data, show or plot how the actual head rise, \(h_a\), and the pump efficiency, \(\eta\), vary with the flowrate. What is the design flowrate for this pump?

In Example 12.3, how will the maximum height, \(z_1\), that the pump can be located above the water surface change if the water temperature is decreased to \(\mathrm{40~^\circ F}\)?

In Example 12.3, how will the maximum height, \(z_1\), that the pump can be located above the water surface change if (a) the water temperature is increased to \(120~^\circ \mathrm{F}\), or (b) the fluid is changed from water to gasoline at \(60 ~^\circ \mathrm{F}\)?

A centrifugal pump with a 7-in.-diameter impeller has the performance characteristics shown in Fig. 12.12. The pump is used to pump water at \(100 ~^\circ \mathrm{F}\), and the pump inlet is located 12 ft above the open water surface. When the flowrate is 200 gpm, the head loss between the water surface and the pump inlet is 6 ft of water. Would you expect cavitation in the pump to be a problem? Assume standard atmospheric pressure. Explain how you arrived at your answer.

Water at \(40~^\circ \mathrm{C}\) is pumped from an open tank through 200 m of 50-mm-diameter smooth horizontal pipe as shown in Fig. P12.22 and discharges into the atmosphere with a velocity of 3 m/s. Minor losses are negligible. (a) If the efficiency of the pump is 70%, how much power is being supplied to the pump? (b) What is the \(\mathrm{NPSH_A}\) at the pump inlet? Neglect losses in the short section of pipe connecting the pump to the tank. Assume standard atmospheric pressure.

A small model of a pump is tested in the laboratory and found to have a specific speed, \(N_sd\), equal to 1000 when operating at peak efficiency. Predict the discharge of a larger, geometrically similar pump operating at peak efficiency at a speed of 1800 rpm across an actual head rise of 200 ft.

The centrifugal pump shown in Fig. P12.24 is not self-priming. That is, if the water is drained from the pump and pipe as shown in Fig. P12.24(a), the pump will not draw the water into the pump and start pumping when the pump is turned on. However, if the pump is primed [i.e., filled with water as in Fig. P12.24(b)], the pump does start pumping water when turned on. Explain this behavior.

Contrast the advantages and disadvantages of using pumps in parallel and in series.

Owing to fouling of the pipe wall, the friction factor for the pipe of Example 12.4 increases from 0.02 to 0.03. Determine the new flowrate, assuming all other conditions remain the same. What is the pump efficiency at this new flowrate? Explain how a line valve could be used to vary the flowrate through the pipe of Example 12.4. Would it be better to place the valve upstream or downstream of the pump? Why?

A centrifugal pump having a head-capacity relationship given by the equation \(h_a =180- 6.10 \times 10^{-4} ~Q^2\), with \(h_a\) in feet when Q is in gpm, is to be used with a system similar to that shown in Fig. 12.14. For \(z_2 - z_1 = 50 \text{ ft}\), what is the expected flowrate if the total length of constant diameter pipe is 600 ft and the fluid is water? Assume the pipe diameter to be 4 in. and the friction factor to be equal to 0.02. Neglect all minor losses.

A centrifugal pump having a 6-in.-diameter impeller and the characteristics shown in Fig. 12.12 is to be used to pump gasoline through 4000 ft of commercial steel 3-in.-diameter pipe. The pipe connects two reservoirs having open surfaces at the same elevation. Determine the flowrate. Do you think this pump is a good choice? Explain.

Determine the new flowrate for the system described in Problem 12.28 if the pipe diameter is increased from 3 in. to 4 in. Is this pump still a good choice? Explain.

A centrifugal pump having the characteristics shown in Example 12.4 is used to pump water between two large open tanks through 100 ft of 8-in.-diameter pipe. The pipeline contains four regular flanged \(90^\circ\) elbows, a check valve, and a fully open globe valve. Other minor losses are negligible. Assume the friction factor f = 0.02 for the 100-ft section of pipe. If the static head (difference in height of fluid surfaces in the two tanks) is 30 ft, what is the expected flowrate? Do you think this pump is a good choice? Explain.

In a chemical processing plant a liquid is pumped from an open tank, through a 0.1-m-diameter vertical pipe, and into another open tank as shown in Fig. P12.31(a). A valve is located in the pipe, and the minor loss coefficient for the valve as a function of the valve setting is shown in Fig. P12.31(b). The pump head-capacity relationship is given by the equation \(h_a = 52.0 - 1.01 \times 10^3 ~Q^2\) with \(h_a\) in meters when Q is in \(\mathrm{m^3 /s}\). Assume the friction factor f = 0.02 for the pipe, and all minor losses, except for the valve, are negligible. The fluid levels in the two tanks can be assumed to remain constant. (a) Determine the flowrate with the valve wide open. (b) Determine the required valve setting (percent open) to reduce the flowrate by 50%.

Water is pumped between the two tanks described in Example 12.4 once a day, 365 days a year, with each pumping period lasting two hours. The water levels in the two tanks remain essentially constant. Estimate the annual cost of the electrical power needed to operate the pump if it were located in your city. You will have to make a reasonable estimate for the efficiency of the motor used to drive the pump. Due to aging, it can be expected that the overall resistance of the system will increase with time. If the operating point shown in Fig. E12.4c changes to a point where the flowrate has been reduced to 1000 gpm, what will be the new annual cost of operating the pump? Assume that the cost of electrical power remains the same.

What is the rationale for operating two geometrically similar pumps differing in feature size at the same flow coefficient?

A centrifugal pump having an impeller diameter of 1 m is to be constructed so that it will supply a head rise of 200 m at a flowrate of \(\mathrm{4.1~ m^3 /s }\) of water when operating at a speed of 1200 rpm. To study the characteristics of this pump, a 1/5 scale, geometrically similar model operated at the same speed is to be tested in the laboratory. Determine the required model discharge and head rise. Assume that both model and prototype operate with the same efficiency (and therefore the same flow coefficient).

A centrifugal pump with a 12-in.-diameter impeller requires a power input of 60 hp when the flowrate is 3200 gpm against a 60-ft head. The impeller is changed to one with a 10-in. diameter. Determine the expected flowrate, head, and input power if the pump speed remains the same.

Do the head–flowrate data shown in Fig. 12.12 appear to follow the similarity laws as expressed by Eqs. 12.39 and 12.40? Explain.

A centrifugal pump has the performance characteristics of the pump with the 6-in.-diameter impeller described in Fig. 12.12. Note that the pump in this figure is operating at 3500 rpm. What is the expected head gained if the speed of this pump is reduced to 2800 rpm while operating at peak efficiency?

A centrifugal pump provides a flowrate of 500 gpm when operating at 1750 rpm against a 200-ft head. Determine the pump’s flowrate and developed head if the pump speed is increased to 3500 rpm.

Use the data given in Problem 12.18 and plot the dimensionless coefficients \(C_H, C_\mathscr P, \eta\) versus \(C_Q\) for this pump. Calculate a meaningful value of specific speed, discuss its usefulness, and compare the result with data of Fig. 12.18.

In a certain application, a pump is required to deliver 5000 gpm against a 300-ft head when operating at 1200 rpm. What type of pump would you recommend?

Explain how a marine propeller and an axial-flow pump are similar in the main effect they produce.

A certain axial-flow pump has a specific speed of \(N_s = 5.0\). If the pump is expected to deliver 3000 gpm when operating against a 15-ft head, at what speed (rpm) should the pump be run?

A certain pump is known to have a capacity of \(\mathrm{3 ~m^3 /s}\) when operating at a speed of 60 rad/s against a head of 20 m. Based on the information in Fig. 12.18, would you recommend a radial-flow, mixed-flow, or axial-flow pump?

Fuel oil (\(\text{sp. wt }= 48.0~\mathrm{ lb/ft^3} ,\text{ viscosity }= 2.0 \times 10^{-5} ~\mathrm{lb \cdot s/ft^2}\)) is pumped through the piping system of Fig. P12.44 with a velocity of 4.6 ft/s. The pressure 200 ft upstream from the pump is 5 psi. Pipe losses downstream from the pump are negligible, but minor losses are not (minor loss coefficients are given on the figure). (a) For a pipe diameter of 2 in. with a relative roughness \(\varepsilon/D = 0.001\), determine the head that must be added by the pump. (b) For a pump operating speed of 1750 rpm, what type of pump (radial-flow, mixed-flow, or axial-flow) would you recommend for this application?

The axial-flow pump shown in Fig. 12.19 is designed to move 5000 gal/min of water over a head rise of 5 ft of water. Estimate the motor power requirement and the \(U_2 V_{\theta 2}\) needed to achieve this flowrate on a continuous basis. Comment on any cautions associated with where the pump is placed vertically in the pipe.

(See Fluids in the News Article titled “Hi-tech Ceiling Fans,” Section 12.7.) Explain why reversing the direction of rotation of a ceiling fan results in airflow in the opposite direction.

For the fan of both Examples 5.19 and 5.28 discuss what fluid flow properties you would need to measure to estimate fan efficiency.

An inward-flow radial turbine (see Fig. P12.48) involves a nozzle angle, \(\alpha_1\), of \(60^\circ\) and an inlet rotor tip speed, \(U_1\), of 3 m/s. The ratio of rotor inlet to outlet diameters is 2.0. The absolute velocity leaving the rotor at section (2) is radial with a magnitude of 6 m/s. Determine the energy transfer per unit mass of fluid flowing through this turbine if the fluid is (a) air, (b) water.

A simplified sketch of a hydraulic turbine runner is shown in Fig. P12.49. Relative to the rotating runner, water enters at section (1) (cylindrical cross section area \(A_1\) at \(r_1 = 1.5 \text{ m}\)) at an angle of \(100^\circ\) from the tangential direction and leaves at section (2) (cylindrical cross section area \(A_2\) at \(r_2 = 0.85 \text{ m}\)) at an angle of \(50^\circ\) from the tangential direction. The blade height at sections (1) and (2) is 0.45 m, and the volume flowrate through the turbine is \(30~\mathrm{ m^3 /s}\). The runner speed is 130 rpm in the direction shown. Determine the shaft power developed. Is the shaft power greater or less than the power lost by the fluid? Explain.

A water turbine wheel rotates at the rate of 100 rpm in the direction shown in Fig. P12.50. The inner radius, \(r_2\), of the blade row is 1 ft, and the outer radius, \(r_1\), is 2 ft. The absolute velocity vector at the turbine rotor entrance makes an angle of \(20^\circ\) with the tangential direction. The inlet blade angle is \(60^\circ\) relative to the tangential direction. The blade outlet angle is \(120^\circ\). The flowrate is \(10 ~\mathrm{ft^3 /s}\). For the flow tangent to the rotor blade surface at inlet and outlet, determine an appropriate constant blade height, b, and the corresponding power available at the rotor shaft. Is the shaft power greater or less than the power lost by the fluid? Explain.

A sketch of the arithmetic mean radius blade sections of an axial-flow water turbine stage is shown in Fig. P12.51. The rotor speed is 1500 rpm. (a) Sketch and label velocity triangles for the flow entering and leaving the rotor row. Use V for absolute velocity, W for relative velocity, and U for blade velocity. Assume flow enters and leaves each blade row at the blade angles shown. (b) Calculate the work per unit mass delivered at the shaft.

An inward flow radial turbine (see Fig. P12.52) involves a nozzle angle, \(\alpha_1\), of \(60^\circ\) and an inlet rotor tip speed, \(U_1\), of 9 m/s. The ratio of rotor inlet to outlet diameters is 2.0. The radial component of velocity remains constant at 6 m/s through the rotor, and the flow leaving the rotor at section (2) is without angular momentum. If the flowing fluid is water and the stagnation pressure drop across the rotor is 110 kPa, determine the loss of available energy across the rotor and the efficiency involved.

Consider the Pelton wheel turbine illustrated in Figs. 12.24, 12.25, 12.26, and 12.27. This kind of turbine is used to drive the oscillating sprinkler shown in Video V12.4. Explain how this kind of sprinkler is started, and subsequently operated at constant oscillating speed. What is the physical significance of the zero torque condition with the Pelton wheel rotating?

A small Pelton wheel is used to power an oscillating lawn sprinkler as shown in Video V12.4 and Fig. P12.54. The arithmetic mean radius of the turbine is 1 in., and the exit angle of the blade is \(135^\circ\) relative to the blade motion. Water is supplied through a single 0.20-in.-diameter nozzle at a speed of 50 ft/s. Determine the flowrate, the maximum torque developed, and the maximum power developed by this turbine.

A Pelton wheel turbine is illustrated in Fig. P12.55. The radius to the line of action of the tangential reaction force on each vane is 1 ft. Each vane deflects fluid by an angle of \(135^\circ\) as indicated. Assume all of the flow occurs in a horizontal plane. Each of the four jets shown strikes a vane with a velocity of 100 ft/s and a stream diameter of 1 in. The magnitude of velocity of the jet remains constant along the vane surface. (a) How much torque is required to hold the wheel stationary? (b) How fast will the wheel rotate if shaft torque is negligible, and what practical situation is simulated by this condition?

The single-stage, axial-flow turbomachine shown in Fig. P12.56 involves water flow at a volumetric flowrate of \(9 ~\mathrm{m^3 /s}\). The rotor revolves at 600 rpm. The inner and outer radii of the annular flow path through the stage are 0.46 and 0.61 m, and \(\beta_2= 60^\circ\). The flow entering the rotor row and leaving the stator row is axial when viewed from the stationary casing. Is this device a turbine or a pump? Estimate the amount of power transferred to or from the fluid.

For an air turbine of a dentist’s drill like the one shown in Fig. E12.8 and Video V12.5, calculate the average blade speed associated with a rotational speed of 350,000 rpm. Estimate the air pressure needed to run this turbine.

Water for a Pelton wheel turbine flows from the headwater and through the penstock as shown in Fig. P12.58. The effective friction factor for the penstock, control valves, and the like is 0.032, and the diameter of the jet is 0.20 m. Determine the maximum power output.

A 10.9-ft-diameter Pelton wheel operates at 500 rpm with a total head just upstream of the nozzle of 5330 ft. Estimate the diameter of the nozzle of the single-nozzle wheel if it develops 25,000 horsepower.

A Pelton wheel has a diameter of 2 m and develops 500 kW when rotating 180 rpm. What is the average force of the water against the blades? If the turbine is operating at maximum efficiency, determine the speed of the water jet from the nozzle and the mass flowrate.

Water to run a Pelton wheel is supplied by a penstock of length \(\ell\) and diameter D with a friction factor f. If the only losses associated with the flow in the penstock are due to pipe friction, show that the maximum power output of the turbine occurs when the nozzle diameter, \(D_1\), is given by \(D_1= D/(2f~ \ell /D) ^{1/4}\).

A Pelton wheel is supplied with water from a lake at an elevation H above the turbine. The penstock that supplies the water to the wheel is of length \(\ell\), diameter D, and friction factor f. Minor losses are negligible. Show that the power developed by the turbine is maximum when the velocity head at the nozzle exit is 2H/3. Note: The result of Problem 12.61 may be of use.

If there is negligible friction along the blades of a Pelton wheel, the relative speed remains constant as the fluid flows across the blades, and the maximum power output occurs when the blade speed is one-half the jet speed (see Eq.12.52). Consider the case where friction is not negligible and the relative speed leaving the blade is some fraction, c, of the relative speed entering the blade. That is, \(W_2= cW_1\). Show that Eq. 12.52 is valid for this case also.

A 1-m-diameter Pelton wheel rotates at 300 rpm. Which of the following heads (in meters) would be best suited for this turbine: (a) 2, (b) 5, (c) 40, (d) 70, or (e) 140? Explain.

A hydraulic turbine operating at 180 rpm with a head of 100 ft develops 20,000 horsepower. Estimate the power if the same turbine were to operate under a head of 50 ft.

Draft tubes as shown in Fig. P12.66 are often installed at the exit of Kaplan and Francis turbines. Explain why such draft tubes are advantageous.

Turbines are to be designed to develop 30,000 horsepower while operating under a head of 70 ft and an angular velocity of 60 rpm. What type of turbine is best suited for this purpose? Estimate the flowrate needed.

Water at 400 psi is available to operate a turbine at 1750 rpm. What type of turbine would you suggest to use if the turbine should have an output of approximately 200 hp?

It is desired to produce 50,000 hp with a head of 50 ft and an angular velocity of 100 rpm. How many turbines would be needed if the specific speed is to be (a) 50, (b) 100?

Show how you would estimate the relationship between feature size and power production for a wind turbine like the one shown in Video V12.1.

Test data for the small Francis turbine shown in Fig. P12.71 is given in the following table. The test was run at a constant 32.8-ft head just upstream of the turbine. The Prony brake on the turbine output shaft was adjusted to give various angular velocities, and the force on the brake arm, F, was recorded. Use the given data to plot curves of torque as a function of angular velocity and turbine efficiency as a function of angular velocity.

It is possible to generate power by using the water from your garden hose to drive a small Pelton wheel turbine (see Video V12.4). Provide a preliminary design of such a turbine and estimate the power output expected. List all assumptions and show calculations.

The device shown in Fig. P12.73 is used to investigate the power produced by a Pelton wheel turbine. Water supplied at a constant flowrate issues from a nozzle and strikes the turbine buckets as indicated. The angular velocity, \(\omega\), of the turbine wheel is varied by adjusting the tension on the Prony brake spring, thereby varying the torque, \(T_\mathrm{shaft}\), applied to the output shaft. This torque can be determined from the measured force, R, needed to keep the brake arm stationary as \(T_\mathrm{shaft} = F \ell\), where \(\ell\) is the moment arm of the brake force. Experimentally determined values of \(\omega\) and R are shown in the following table. Use these results to plot a graph of torque as a function of the angular velocity. On another graph plot the power output, \(W_\mathrm{shaft} =T_\mathrm{shaft} ~\omega\), as a function of the angular velocity. On each of these graphs plot the theoretical curves for this turbine, assuming 100% efficiency. Compare the experimental and theoretical results and discuss some possible reasons for any differences between them.

Obtain photographs/images of a variety of turbo-compressor rotors and categorize them as axial-flow or radial-flow compressors. Explain briefly how they are used. Note any unusual features.

Obtain photographs/images of a variety of compressible flow turbines and categorize them as axial-flow or radial-flow turbines. Explain briefly how they are used. Note any unusual features.

What do you think are the major unresolved fluid dynamics problems associated with gas turbine engine compressors? For gas turbine engine high-pressure and low-pressure turbines? For gas turbine engine fans?

Outline the steps associated with the preliminary design of a turbomachine rotor.

What are current efficiencies achieved by the following categories of turbomachines? (a) Wind turbines; (b) hydraulic turbines; (c) power plant steam turbines; (d) aircraft gas turbine engines; (e) natural gas pipeline compressors; (f) home vacuum cleaner blowers; (g) laptop computer cooling fan; (h) irrigation pumps; (i) dentist drill air turbines. What is being done to improve these devices?

(See Fluids in the News Article titled “Cavitation Damage in Hydraulic Turbines,” Section 12.8.2.) How are cavitation and, more importantly, the damage it can cause detected in hydraulic turbines? How can this damage be minimized?