Fox and McDonald's Introduction to Fluid Mechanics
9th Edition
ISBN: 9781118912652
Author: Philip J. Pritchard, John W. Mitchell
Publisher: WILEY
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 7, Problem 49P
A force of 9 N is required to tow a 1:50 ship model at 4:8 km/h. Assuming the same water in towing basin and sea, calculate the corresponding speed and force in the prototype if the flow is dominated by: (a) density and gravity, (b) density and surface tension, and (c) density and viscosity.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A 1:4 scale torpedo model has been built.
The prototype is expected to move at a
speed of 6m/s in water at 15°C. What
should be the velocity in the model if, a) the
test is done in a stream channel at 15°C;
and b) the test is done in a wind tunnel at
27°C and a pressure of 20 atm?
A 1:10 scale model study of a torpedo is proposed. Prototype speeds of 90 km/hare to be studied. Should a wind tunnel or a water facility be used?
A student team is to design a human-powered submarine for a design competition. The overall length of the prototype submarine is 95 (m), and its student designers hope that it can travel fully submerged through water at 0.440 m/s. The water is freshwater (a lake) at T = 15°C. The design team builds a one-fifth scale model to test in their university’s wind tunnel. A shield surrounds the drag balance strut so that the aerodynamic drag of the strut itself does not influence the measured drag. The air in the wind tunnel is at 25°C and at one standard atmosphere pressure. At what air speed do they need to run the wind tunnel in order to achievesimilarity?
Chapter 7 Solutions
Fox and McDonald's Introduction to Fluid Mechanics
Ch. 7 - The slope of the free surface of a steady wave in...Ch. 7 - One-dimensional unsteady flow in a thin liquid...Ch. 7 - In atmospheric studies the motion of the earths...Ch. 7 - Fluid fills the space between two parallel plates....Ch. 7 - By using order of magnitude analysis, the...Ch. 7 - Consider a disk of radius R rotating in an...Ch. 7 - An unsteady, two-dimensional, compressible,...Ch. 7 - Experiments show that the pressure drop for flow...Ch. 7 - At very low speeds, the drag on an object is...Ch. 7 - We saw in Chapter 3 that the buoyant force, FB, on...
Ch. 7 - Assume that the velocity acquired by a body...Ch. 7 - Derive by dimensional analysis an expression for...Ch. 7 - The speed of shallow water waves in the ocean...Ch. 7 - The speed, V, of a free-surface wave in shallow...Ch. 7 - The boundary-layer thickness, , on a smooth flat...Ch. 7 - The speed, V, of a free-surface gravity wave in...Ch. 7 - Derive an expression for the velocity of very...Ch. 7 - Derive an expression for the axial thrust exerted...Ch. 7 - Derive an expression for drag force on a smooth...Ch. 7 - The energy released during an explosion, E, is a...Ch. 7 - Measurements of the liquid height upstream from an...Ch. 7 - The load-carrying capacity, W, of a journal...Ch. 7 - Derive an expression for the drag force on a...Ch. 7 - A circular disk of diameter d and of negligible...Ch. 7 - Two cylinders are concentric, the outer one fixed...Ch. 7 - The time, t, for oil to drain out of a viscosity...Ch. 7 - You are asked to find a set of dimensionless...Ch. 7 - A continuous belt moving vertically through a bath...Ch. 7 - Derive an expression for the frictional torque...Ch. 7 - Tests on the established flow of six different...Ch. 7 - The power, P, required to drive a fan is believed...Ch. 7 - The sketch shows an air jet discharging...Ch. 7 - The diameter, d, of bubbles produced by a...Ch. 7 - Choked-flow nozzles are often used to meter the...Ch. 7 - A large tank of liquid under pressure is drained...Ch. 7 - Spin plays an important role in the flight...Ch. 7 - The power loss, P, in a journal bearing depends on...Ch. 7 - The thrust of a marine propeller is to be measured...Ch. 7 - The rate dT/dt at which the temperature T at the...Ch. 7 - When a valve is closed suddenly in a pipe with...Ch. 7 - An airship is to operate at 20 m/s in air at...Ch. 7 - An airplane wing of 3 m chord length moves through...Ch. 7 - A flat plate 1.5 m long and 0.3 m wide is towed at...Ch. 7 - This 1:12 pump model using water at 15C simulates...Ch. 7 - An ocean-going vessel is to be powered by a...Ch. 7 - On a cruise ship, passengers complain about the...Ch. 7 - A 1:3 scale model of a torpedo is tested in a wind...Ch. 7 - A flow rate of 0:18 m3/s of water at 20C...Ch. 7 - A force of 9 N is required to tow a 1:50 ship...Ch. 7 - An airplane wing, with chord length of 1.5 m and...Ch. 7 - A water pump with impeller diameter of 24 in. is...Ch. 7 - A model hydrofoil is to be tested at 1:20 scale....Ch. 7 - A ship 120 m long moves through freshwater at 15C...Ch. 7 - A 1:30 scale model of a cavitating overflow...Ch. 7 - In some speed ranges, vortices are shed from the...Ch. 7 - A 1:8 scale model of a tractor-trailer rig is...Ch. 7 - On a cruise ship, passengers complain about the...Ch. 7 - When a sphere of 0.25 mm diameter and specific...Ch. 7 - The flow about a 150 mm artillery projectile which...Ch. 7 - Your favorite professor likes mountain climbing,...Ch. 7 - A 1:50-scale model of a submarine is to be tested...Ch. 7 - Consider water flow around a circular cylinder, of...Ch. 7 - A 1:10 scale model of a tractor-trailer rig is...Ch. 7 - The power, P, required to drive a fan is assumed...Ch. 7 - Over a certain range of air speeds, V, the lift,...Ch. 7 - The pressure rise, p, of a liquid flowing steadily...Ch. 7 - An axial-flow pump is required to deliver 0.75...Ch. 7 - A model propeller 1 m in diameter is tested in a...Ch. 7 - Consider Problem 7.38. Experience shows that for...Ch. 7 - Closed-circuit wind tunnels can produce higher...Ch. 7 - A 1:16 model of a bus is tested in a wind tunnel...Ch. 7 - The propagation speed of small-amplitude surface...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
The W10 15 cantilevered beam is made of A-36 steel and is subjected to the loading shown. Determine the displa...
Mechanics of Materials (10th Edition)
Determine the normal stress in each member of the truss structure. All joints are ball joint, and the material ...
Introduction To Finite Element Analysis And Design
What parts are included in the vehicle chassis?
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
In each case, determine the internal normal force between lettered points on the bar. Draw all necessary free-b...
Statics and Mechanics of Materials (5th Edition)
Turnbuckle T1 is tightened to a tension of 750 N and turnbuckle T2 is tightened to 500 N. Determine the compone...
Engineering Mechanics: Statics
3.24 Compute the moment about point A for the linkage shown.
Applied Statics and Strength of Materials (6th Edition)
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
- A 1:20 scaled-down model of a hydrofoil is tested in a water channel, at a velocity of 0.179 m/s. At this velocity, a drag force of 2.2 N is measured. Determine the drag force of the original hydrofoil, at a velocity of 0.8 m/s.arrow_forwardA blimp is designed to move in air at C at 7 m/s. If a 1:20 scale model is tested in water at 20 "C, what should the water velocity be? If the measured water drag on the model is 3.2kN, calculate the drag on the prototype blimp and the power required to propel it. (For water u 1.02x10 pa.s, p 1000 kg/m' and for air a 1.81x10 pa.s, p 1.2kg/m')arrow_forward(a) A model low speed centrifugal compressor (a “blower") runs at 430 rpm and delivers 10 m/s of air against a pressure head of 60 mm of water. If the pump efficiency is estimated to be 80%, how much power is required to drive the compressor? (b) A geometrically similar compressor is made with a diameter 1.8 times the size of the model and is required to work against a pressure head of 80 mm of water. Determine the operating speed and the power needed to drive the compressor assuming dynamically similar condi- tions apply.arrow_forward
- An automobile has a characteristic length and area of 8 ft and 60 ft2, respectively. When tested in sea-level standard air, it has measured velocities of 20, 40, and 60 mi/h and drag forces of 31, 115, and 249 lbf, respectively. The same car travels in Colorado at 115 mi/h at an altitude of 3500 m. Using dimensional analysis, estimate its drag force (in lbf). Using dimensional analysis, estimate the horsepower required to overcome air drag (in hp)arrow_forwardIn the design and development competition in a University, a team of students has planned to develop a prototype submarine with 6.5 meter length that would travel fully submerged at X m/s speed in a fresh lake water. The team has designed a model which has one-sixth of a prototype size to test in the university wind tunnel to study the effect of various parameters, such as drag force on the prototype (Figure Q2). Considering the necessary assumptions (a) determine the speed of the wind the team has to blow into the tunnel in order to achieve similarity. (b) With all the same conditions the team change their mind and want to develop a smaller size of model to save money and time. Targeting the maximum acceptable speed of the air blown not to exceed 125 m/s to avoid compressibility of air, what should be the minimum length of the model? (c) What will happen to the length of the model if the temperature of the blowing wind increases as a result of the season change? Discuss the reason.arrow_forwardA student team is to design a submarine for a design competition. The overall length of the prototype submarine is 4.85 m. The prototype submarine is expected to moves through freshwater in the lake at 0.440 m/s. The student team builds a one-fifth scale model to test in their university's wind tunnel. Calculate the wind tunnel air speed in order to achieve similarity with the prototype submarine. For water at T= 15 °C and atmospheric pressure, the density is p = 999.1 kg/m³ and the dynamic viscosity is µ = 1.138 x 10³ kg/m-s. For air in the wind tunnel at T= 25 °C and atmospheric pressure, the density is p= 1.184 kg/m³ and the dynamic viscosity is µ = 1.849 x 10-$ kg/m's.arrow_forward
- A student needs to measure the drag on a prototype of characteristic length d, moving at velocity U, in air at sea-level conditions. She constructs a model of characteristic length dm such that the ratio d,/dm drag under dynamically similar conditions in sea-level air. The student claims that the drag force on the prototype will be = a factor f. She then measures the model identical to that of the model. Is her claim correct? Explain, showing your work (no credit for just guessing).arrow_forwardWe want to predict the drag force on a remote-control airplane as it flies through air having a density of 1.21 kg/m³ and a viscosity of 1.76x10- Pa-s. The airplane's fuselage has a diameter of 200 mm and the airplane will fly through air at a speed of 32 m/s. A model of the airplane's fuselage will be tested in a pressurized wind tunnel. The diameter of the model is 75 mm and the density and viscosity of the air in the wind tunnel are 3.00 kg/m³ and 1.82× 10-5 Pa-s, respectively. a) The diameter of the airplane's fuselage will be used to define the Reynolds number Re, for the flow around the fuselage. Compute the Reynolds number for the flow around the airplane's fuselage (answer: Re, = 4.40x 10'). b) Find the speed of the air that should be used to test a model of the fuselage in the wind tunnel to correctly model dynamic conditions (answer: 35.6 m/s). c) The model is tested in the wind tunnel at four speeds that bracket the speed computed above. The measured drag forces on the…arrow_forwardThe drag force on a submarine, which is moving on the surface, is to be determined by a test on a model which is scaled down to one-twentieth of the prototype. The test is to be carried in a towing tank, where the model submarine is moved along a channel of liquid. The density and the kinematic viscosity of the seawater are 1010 kg/m³ and 1.3x10-6 m 2/s, respectively. The speed of the prototype is 2.6 m/s. Assume that F = f(V, L. g. p.), using pi-theorem and similarity principle to: a) Determine the speed at which the model should be moved in the towing tank. b) Determine the kinematic viscosity of the liquid that should be used in the towing tank.arrow_forward
- Wind blows and pasts a banner causes it to flutter. The fluttering frequency f is a function of the wind speed V, the air density ρ, the acceleration of gravity g, the length of the banner L and the “area density” of the flag material ρA (with dimensions of ML-2 ). In order to estimate the flutter frequency of a large banner with L = 40 ft in a V = 30 ft/s wind, a small banner with L = 4 ft is to be tested in a wind tunnel. (a) What is the area density of the small banner when the large banner has area density of 0.006 slugs/ft2? (b) What should the wind tunnel velocity be to test the small model? (c) It has been shown that the small banner flutters at 6 s-1 when the same area density and wind tunnel velocity are used in parts (a) and (b). In this case, what is the fluttering frequency of the large banner?arrow_forwardWhen a uniform stream flows past an immersed thick cylinder, a broad low-velocity wake is created downstream, idealized as a V shape in Fig. 1. Pressures p1 and p2 are approximately equal. (a) If the flow is two-dimensional and incompressible, with width b into the paper, derive a formula for the drag force F on the cylinder. (b) 1. Rewrite your result in the form of a dimensionless drag coefficient based on body F length Cp pU²bL U = L Fig.1. Airflow on a cylinder U U U/2 L/2 L/2arrow_forwardusing pure water at 20°C. The velocity of the prototype in seawater (p = A 1/18 scale model of the submarine is to be tested in the water tunnel 1015 kg/m³, v = 1.4x106 m²/s) is 3 m/s. Determine: a) the speed of the water in the water tunnel for dynamic similarity D) the ratio of the drag force on the model to the drag force on the prototypearrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University Press
Mechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSON
Thermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEY
Mechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage Learning
Engineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
Unit Conversion the Easy Way (Dimensional Analysis); Author: ketzbook;https://www.youtube.com/watch?v=HRe1mire4Gc;License: Standard YouTube License, CC-BY