Connect 1 Semester Access Card For Fluid Mechanics
8th Edition
ISBN: 9781259151415
Author: Frank White
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 7, Problem 7.1DP
It is desired to design a cup anemometer for wind speed, similar to Fig. P7.91, with a more sophisticated approach than the “average-torque” method of Prob. P7.91. The design should achieve an approximately linear relation between wind velocity and rotation rate in the range 20 < U < 40 mi/h, and the anemometer should rotate at about 6 r/s at U = 30 mi/h. All speci?cations—cup diameter D, rod length L, rod diameter d, the bearing type, and all materials—are to be selected through your analysis. Make suitable assumptions about the instantaneous drag of the cups and rods at any given angle
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Some engineers want a good estimate of drag and boundary-layerthickness at the trailing edge of a miniature wing. The chord and span ofthe wing are 6 mm and 30 mm, respectively and a typical flight speed is5 m/s in air (kinematic viscosity = 15 × 10−6 m2/s; density = 1.2kg/m3). An engineer may decide to make a superseding model withchord and span of 150 mm and 750 mm, respectively. Measurements onthe model in a water channel flowing at 0.5 m/s (kinematic viscosity = 1× 10−6 m2/s, density = 1000 kg/m3) give a drag of 0.19 N and aboundary-layer thickness of 3 mm. Estimate the corresponding values forthe prototype
Assume an inviscid, incompressible flow. Also, standard sea level density and pressure are 1.23 kg/m3 (0.002377 slug/ft3) and 1.01 × 105 N/m2 (2116 lb/ft2), respectively.
Consider the nonlifting flow over a circular cylinder of a given radius,where V∞ = 20 ft/s. If V∞ is doubled, that is, V∞ = 40 ft/s, does theshape of the streamlines change? Explain.
Consider two pressure taps along the wall of a laminar boundary layer as in Fig. The fluid is air at 25°C, U1 = 13.7 m/s, and the static pressure P1 is 2.96 Pa greater than static pressure P2, as measured by a very sensitive differential pressure transducer. Is outer flow velocity U2 greater than, equal to, or less than outer flow velocity U1? Explain. Estimate U2
Chapter 7 Solutions
Connect 1 Semester Access Card For Fluid Mechanics
Ch. 7 - Prob. 7.1PCh. 7 - A gas at 20°C and 1 atm flows at 6 ft/s past a...Ch. 7 - Prob. 7.3PCh. 7 - Prob. 7.4PCh. 7 - SAE 30 oil at 20°C flows at 1.8 ft3/s from a...Ch. 7 - Prob. 7.6PCh. 7 - P7.7 Air at 20°C and 1 atm enters a 40-cm-square...Ch. 7 - P7.8 Air, p = 1.2 kg/m3 and E-5 kg/(m .s), flows...Ch. 7 - P7.9 Repeat the flat-plate momentum analysis of...Ch. 7 - Repeat Prob. P7.9, using a trigonometric profile...
Ch. 7 - Prob. 7.11PCh. 7 - Prob. 7.12PCh. 7 - Prob. 7.13PCh. 7 - Prob. 7.14PCh. 7 - Prob. 7.15PCh. 7 - A thin flat plate 55 by 110 cm is immersed in a...Ch. 7 - Consider laminar flow past a sharp flat plate of...Ch. 7 - Air at 20°C and 1 atm flows at 5 m/s past a flat...Ch. 7 - Prob. 7.19PCh. 7 - Air at 20°C and I atm flows at 20 m/s past the...Ch. 7 - Prob. 7.21PCh. 7 - Prob. 7.22PCh. 7 - Prob. 7.23PCh. 7 - Prob. 7.24PCh. 7 - Prob. 7.25PCh. 7 - P7.26 Consider laminar boundary layer flow past...Ch. 7 - Prob. 7.27PCh. 7 - Prob. 7.28PCh. 7 - Prob. 7.29PCh. 7 - Prob. 7.30PCh. 7 - Prob. 7.31PCh. 7 - Prob. 7.32PCh. 7 - Prob. 7.33PCh. 7 - Prob. 7.34PCh. 7 - Prob. 7.35PCh. 7 - Prob. 7.36PCh. 7 - Prob. 7.37PCh. 7 - Prob. 7.38PCh. 7 - P7.39 A hydrofoil 50 cm long and 4 m wide moves...Ch. 7 - Prob. 7.40PCh. 7 - Prob. 7.41PCh. 7 - Prob. 7.42PCh. 7 - Prob. 7.43PCh. 7 - Prob. 7.44PCh. 7 - P7.45 A thin sheet of fiberboard weighs 90 N and...Ch. 7 - Prob. 7.46PCh. 7 - Prob. 7.47PCh. 7 - Prob. 7.48PCh. 7 - Based strictly on your understanding of flat-plate...Ch. 7 - Prob. 7.50PCh. 7 - Prob. 7.51PCh. 7 - Prob. 7.52PCh. 7 - Prob. 7.53PCh. 7 - *P7.54 If a missile takes off vertically from sea...Ch. 7 - Prob. 7.55PCh. 7 - Prob. 7.56PCh. 7 - Prob. 7.57PCh. 7 - Prob. 7.58PCh. 7 - Prob. 7.59PCh. 7 - Prob. 7.60PCh. 7 - Prob. 7.61PCh. 7 - A sea-level smokestack is 52 m high and has a...Ch. 7 - For those who think electric cars are sissy, Keio...Ch. 7 - Prob. 7.64PCh. 7 - Prob. 7.65PCh. 7 - Prob. 7.66PCh. 7 - The Toyota Prius has a drag coefficient of 0.25, a...Ch. 7 - Prob. 7.68PCh. 7 - Prob. 7.69PCh. 7 - P7.70 The Army’s new ATPS personnel parachute is...Ch. 7 - Prob. 7.71PCh. 7 - Prob. 7.72PCh. 7 - Prob. 7.73PCh. 7 - Prob. 7.74PCh. 7 - Prob. 7.75PCh. 7 - P7.76 The movie The World’s Fastest Indian tells...Ch. 7 - Prob. 7.77PCh. 7 - Prob. 7.78PCh. 7 - Prob. 7.79PCh. 7 - Prob. 7.80PCh. 7 - Prob. 7.81PCh. 7 - Prob. 7.82PCh. 7 - Prob. 7.83PCh. 7 - P7.84 A Ping-Pong ball weighs 2.6 g and has a...Ch. 7 - Prob. 7.85PCh. 7 - Prob. 7.86PCh. 7 - P7.87 A tractor-trailer truck has a drag area CA =...Ch. 7 - P7.88 A pickup truck has a clean drag area CDA of...Ch. 7 - Prob. 7.89PCh. 7 - Prob. 7.90PCh. 7 - Prob. 7.91PCh. 7 - Prob. 7.92PCh. 7 - A hot-film probe is mounted on a cone-and-rod...Ch. 7 - Baseball drag data from the University of Texas...Ch. 7 - Prob. 7.95PCh. 7 - Prob. 7.96PCh. 7 - Prob. 7.97PCh. 7 - A buoyant ball of specific gravity SG 1 dropped...Ch. 7 - Prob. 7.99PCh. 7 - Prob. 7.100PCh. 7 - Prob. 7.101PCh. 7 - Prob. 7.102PCh. 7 - Prob. 7.103PCh. 7 - Prob. 7.104PCh. 7 - Prob. 7.105PCh. 7 - Prob. 7.106PCh. 7 - Prob. 7.107PCh. 7 - Prob. 7.108PCh. 7 - Prob. 7.109PCh. 7 - Prob. 7.110PCh. 7 - Prob. 7.111PCh. 7 - Prob. 7.112PCh. 7 - Prob. 7.113PCh. 7 - Prob. 7.114PCh. 7 - Prob. 7.115PCh. 7 - Prob. 7.116PCh. 7 - Prob. 7.117PCh. 7 - Suppose that the airplane of Prob. P7.116 is...Ch. 7 - Prob. 7.119PCh. 7 - Prob. 7.120PCh. 7 - Prob. 7.121PCh. 7 - Prob. 7.122PCh. 7 - Prob. 7.123PCh. 7 - Prob. 7.124PCh. 7 - Prob. 7.125PCh. 7 - Prob. 7.126PCh. 7 - Prob. 7.127PCh. 7 - Prob. 7.1WPCh. 7 - Prob. 7.2WPCh. 7 - Prob. 7.3WPCh. 7 - Prob. 7.4WPCh. 7 - Prob. 7.5WPCh. 7 - Prob. 7.6WPCh. 7 - Prob. 7.7WPCh. 7 - Prob. 7.8WPCh. 7 - Prob. 7.9WPCh. 7 - How does the concept of drafting, in automobile...Ch. 7 - Prob. 7.11WPCh. 7 - Prob. 7.12WPCh. 7 - Prob. 7.1FEEPCh. 7 - Prob. 7.2FEEPCh. 7 - Prob. 7.3FEEPCh. 7 - Prob. 7.4FEEPCh. 7 - Prob. 7.5FEEPCh. 7 - Prob. 7.6FEEPCh. 7 - Prob. 7.7FEEPCh. 7 - Prob. 7.8FEEPCh. 7 - Prob. 7.9FEEPCh. 7 - Prob. 7.10FEEPCh. 7 - Prob. 7.1CPCh. 7 - Prob. 7.2CPCh. 7 - Prob. 7.3CPCh. 7 - Prob. 7.4CPCh. 7 - Prob. 7.5CPCh. 7 - It is desired to design a cup anemometer for wind...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- SAE 30 oil at 20 °C flows at 1.8 ft3/s from a reservoir into a6-in-diameter pipe. Use flat-plate theory to estimate theposition x where the pipe wall boundary layers meet in thecenter. Compare with Eq., Le/d≈ 0.06 Red laminar and give some explanationsfor the discrepancy.arrow_forwardAir at 20°C and 1 atm enters a 40-cm-square duct as in Fig.P7.7. Using the “displacement thickness” concept estimate (a) the mean velocity and (b) the mean pressure inthe core of the flow at the position x = 3 m. (c) What is theaverage gradient, in Pa/m, in this section?arrow_forwardA long, slender, smooth 3-cm-diameter flagpole bendsalarmingly in 20 mi/h sea-level winds, causing patrioticcitizens to gasp. An engineer claims that the pole will bendless if its surface is deliberately roughened. Is she correct,at least qualitatively?arrow_forward
- Assume an inviscid, incompressible flow. Also, standard sea level density and pressure are 1.23 kg/m3 (0.002377 slug/ft3) and 1.01 × 105 N/m2 (2116 lb/ft2), respectively. Derive the velocity potential for a doublet.arrow_forwardConsider a rectangular wing mounted in a wind tunnel. The wing model completely spans the testsection so that the flow sees essentially an infinite wing. The wing has a NACA 2421 airfoil section,a chord of 3.0 m, and a span of 20 m. The tunnel is operated at the following test conditions: P =101,000 N/m2; T = 35° C; V = 50 m/s; and µ = 1.9 * 10 -5 kg/(m s).(a) Determine the operating Reynolds number.(b) Calculate the lift, drag, and moment about the aerodynamic center for an angle of attack of 8 deg andRe=9*106(c) At a Reynolds number of 3 * 106, find the following:1) What is the stalling angle of attack for this airfoil?2) What is the angle of attack for zero lift?3) What is the lift-curve slope?arrow_forwardAir at 20C flows at 1 m/s between two parallel flat plates spaced 5 cm apart. Estimate the distance from the entrance to the point at which the hydrodynamic boundary layers meet.arrow_forward
- Select an appropriate set of variables that influencethe drag force FD on an airfoil (Fig. P6.23) andwrite the final form in terms of dimensionlessparameters.arrow_forwardAssume an inviscid, incompressible flow. Also, standard sea level density and pressure are 1.23 kg/m3 (0.002377 slug/ft3) and 1.01 × 105 N/m2 (2116 lb/ft2), respectively. Consider the lifting flow over a circular cylinder of a given radius and witha given circulation. If V∞ is doubled, keeping the circulation the same,does the shape of the streamlines change? Explain.arrow_forwardA smooth wooden sphere (SG = 0.65) is connected by athin rigid rod to a hinge in a wind tunnel, as in Fig. Air at 20°C and 1 atm flows and levitates the sphere.(a) Plot the angle θ versus sphere diameter d in the range1 cm≤ d≤15 cm. (b) Comment on the feasibility of thisconfiguration. Neglect rod drag.arrow_forward
- In the flow of air at 20°C and 1 atm past a flat plate inFig. , the wall shear is to be determined at position x bya floating element (a small area connected to a strain-gageforce measurement). At x = 2 m, the element indicates ashear stress of 2.1 Pa. Assuming turbulent flow from the leadingedge, estimate (a) the stream velocity U, (b) the boundarylayer thickness δ at the element, and (c) the boundary layervelocity u, in m/s, at 5 mm above the element.arrow_forwardA certain garden hose is advertised to be able to deliver 550 gallons of water per hour. If the hose if 50 feet long and has an inside diameter of 5/8 inch, estimate the water pressure necessary to deliver this much water, assuming laminar flow and viscosity at 1.002 x 10-3 kg/(m-s). a. 10,664 Pa b. 0.42785 atm c. 0.8218 atm d. 42.49 torrarrow_forwardA sample of powdered zinc oxide, density 5.60g/cm 3 , is allowed to settle under the accelerationof gravity, 981 cm/sec 2 , at 25 25°C. The rate ofsettling, v, is 7.30 ×10 3 cm/sec; the density ofthe medium is 1.01 g/cm 3 , and its viscosity is 1centipoise = 0.01 poise or 0.01 g/cm sec.Calculate the Stokes diameter of the zinc oxidepowder.Problem:arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
Physics 33 - Fluid Statics (1 of 10) Pressure in a Fluid; Author: Michel van Biezen;https://www.youtube.com/watch?v=mzjlAla3H1Q;License: Standard YouTube License, CC-BY