Fluid Mechanics: Fundamentals and Applications
4th Edition
ISBN: 9781259696534
Author: Yunus A. Cengel Dr., John M. Cimbala
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 11, Problem 31P
A submarine can be treated as an ellipsoid with a diameter of 5 m and a length of 25 m. Determine the power required for this submarine to cruise horizontally and steadily at 40 km/h in seawater whose density is 102$ kg/m3. Also determine the power required to tow this submarine in air whose density is 1.30 kg/m3. Assume the flow is turbulent in both cases.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A submarine can be treated as an ellipsoid with a diameter of 5 m and a length of 25 m. Determine the power required for this submarine to cruise horizontally and steadily at 40 km/h in seawater whose density is 1025 kg/m3. Also determine the power required to tow this submarine in air whose density is 1.30 kg/m3. Assume the flow is turbulent in both cases.
Throughout, take the acceleration due to gravity to be 10 m/s? and water to have density of 1000 kg/m³.
Question 1
A large block of mass 1100 kg is towed at a constant speed UB up an inclined plane at 6° to the
horizontal, as shown in Fig. 1. The towing force applied on the block has magnitude 1165 N. The
block slides over an oil film with a constant thickness of 3 mm. The oil has density 900 kg/m and
dynamic viscosity 0.1 Pa.s. The area of the block in contact with the oil is 15 m2.
UB
F=1165 N
m=1100 kg
oil film
3 mm
contact area: 15 m²
6°
Figure 1
(i) Sketch, with appropriate labels, the forces acting on the block in the direction parallel to the
inclined plane.
(ii) Determine the magnitude of the drag force acting on the bottom surface of the block.
(iii) Assuming a laminar velocity profile in the oil film, determine the speed of the block Ug.
(iv) Verify that the flow of oil is laminar as assumed in (iii).
(v) Determine the power requirement to tow the block.
(vi) To reduce the…
Spaces h1=15 mm and h2=20 mm wide between upper and lower stationary plates and a very thin moving plate is filled with crude oil (oil =7.18x10-3 Pas) and water (water =1.00x10-3 Pas), respectively. What force is required to drag the plate of 0.5 m2 area between the surfaces at a speed of v=0.15 m/s. Assume linear velocity profile
Chapter 11 Solutions
Fluid Mechanics: Fundamentals and Applications
Ch. 11 - What is drag? What causes it? Why do we usually...Ch. 11 - Prob. 2CPCh. 11 - Which bicyclist is more likely to go faster: one...Ch. 11 - Prob. 4CPCh. 11 - Define the frontal area of a body subjected to...Ch. 11 - Define the planform area of a body subjected to...Ch. 11 - Prob. 7CPCh. 11 - What is the difference between streamlined and...Ch. 11 - Prob. 9CPCh. 11 - During flow over a given body, the drag force, the...
Ch. 11 - During flow over a given slender body such as a...Ch. 11 - What is terminal velocity? How is it determined?Ch. 11 - What is the difference between skin friction drag...Ch. 11 - What is the effect of surface roughness on the...Ch. 11 - Prob. 15CPCh. 11 - What is flow separation? What causes it? What is...Ch. 11 - Prob. 17CPCh. 11 - Consider laminar flow over a flat plate. How does...Ch. 11 - In general, how does the drag coefficient vary...Ch. 11 - Fairings are attached to the front and back of a...Ch. 11 - Prob. 21PCh. 11 - The resultant of the pressure and wall shear...Ch. 11 - Prob. 23PCh. 11 - Prob. 24PCh. 11 - To reduce the drag coefficient and thus to improve...Ch. 11 - A circular sign has a diameter of 50 cm and is...Ch. 11 - Prob. 28PCh. 11 - Prob. 29PCh. 11 - At highway speeds, about half of the power...Ch. 11 - A submarine can be treated as an ellipsoid with a...Ch. 11 - A 70-kg bicyclist is riding her 1 5-kg bicycle...Ch. 11 - A wind turbine with two or four hollow...Ch. 11 - During steady motion of a vehicle on a level road,...Ch. 11 - Prob. 37EPCh. 11 - A 0.80-m-diameter, 1 .2-rn-high garbage can is...Ch. 11 - An 8-mm-diameter plastic sphere whose density is...Ch. 11 - Prob. 40PCh. 11 - The drag coefficient of a vehicle increases when...Ch. 11 - To reduce the drag coefficient and thus to improve...Ch. 11 - During major windstorms, high vehicles such as RVs...Ch. 11 - What does the friction coefficient represent in...Ch. 11 - What fluid property is responsible for the...Ch. 11 - How is the average friction coefficient determined...Ch. 11 - Prob. 47EPCh. 11 - The local atmospheric pressure in Denver, Colorado...Ch. 11 - Prob. 50PCh. 11 - Prob. 51EPCh. 11 - Air at 25C and 1 atm is flowing over a long flat...Ch. 11 - Prob. 54PCh. 11 - During a winter day, wind at 70 km/h, 5C , and I...Ch. 11 - Prob. 56PCh. 11 - The forming section of a plastics plant puts out a...Ch. 11 - Prob. 58CPCh. 11 - Why is flow separation in flow over cylinders...Ch. 11 - Prob. 60CPCh. 11 - A 5-mm-diameter electrical transmission line is...Ch. 11 - A 1ong 5-cm-diameter steam pipe passes through...Ch. 11 - Consider 0.8-cm-diameter hail that is falling...Ch. 11 - Prob. 64EPCh. 11 - Prob. 65PCh. 11 - Prob. 66PCh. 11 - Prob. 67EPCh. 11 - One of the popular demonstrations in science...Ch. 11 - Prob. 69PCh. 11 - What is stall? What causes an airfoil to stall?...Ch. 11 - Prob. 71CPCh. 11 - Air is flowing past a symmetrical airfoil at zero...Ch. 11 - Both the lift and the drag of an airfoil increase...Ch. 11 - Prob. 74CPCh. 11 - Prob. 75CPCh. 11 - Air is flowing past a symmetrical airfoil at an...Ch. 11 - Prob. 77CPCh. 11 - Prob. 78CPCh. 11 - Prob. 79CPCh. 11 - Prob. 80CPCh. 11 - How do flaps affect the lift and the drag of...Ch. 11 - Prob. 82EPCh. 11 - Consider an aircraft that takes off at 260 km/h...Ch. 11 - Prob. 84PCh. 11 - Prob. 85PCh. 11 - A tennis ball with a mass of 57 and a diameter of...Ch. 11 - A small aircraft has a wing area of 40 m2, a lift...Ch. 11 - Prob. 89PCh. 11 - Consider a light plane that has a total weight of...Ch. 11 - A small airplane has a total mass of 1800 kg and a...Ch. 11 - An airplane has a mass of 48.000 k. a wins area of...Ch. 11 - Prob. 93EPCh. 11 - Prob. 94PCh. 11 - Prob. 95EPCh. 11 - A 2-zn-high, 4-zn-wide rectangular advertisement...Ch. 11 - 11-97 A plastic boat whose bottom surface can be...Ch. 11 - Prob. 99PCh. 11 - Prob. 100EPCh. 11 - A commercial airplane has a total mass of 150.000...Ch. 11 - Prob. 102PCh. 11 - Prob. 103PCh. 11 - Prob. 104PCh. 11 - Prob. 105PCh. 11 - Prob. 107PCh. 11 - Prob. 108PCh. 11 - Prob. 109PCh. 11 - Prob. 110PCh. 11 - Prob. 111PCh. 11 - Prob. 113PCh. 11 - Prob. 115PCh. 11 - Prob. 116PCh. 11 - Prob. 117PCh. 11 - Prob. 118PCh. 11 - Prob. 119PCh. 11 - The region of flow trailing the body where the...Ch. 11 - Prob. 121PCh. 11 - Prob. 122PCh. 11 - Prob. 123PCh. 11 - Prob. 124PCh. 11 - Prob. 125PCh. 11 - Prob. 126PCh. 11 - An airplane has a total mass of 3.000kg and a wing...Ch. 11 - Prob. 128PCh. 11 - Write a report on the history of the reduction of...Ch. 11 - Write a report oil the flips used at the leading...Ch. 11 - Discuss how to calculate drag force a unsteady...Ch. 11 - Large commercial airplanes cruise at high...Ch. 11 - Many drivers turn off their air conditioners and...Ch. 11 - Consider the boundary layer growing on a flat...
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
- When rowing downstream consider the following scenario. The current of the water is moving at 2 m/s in the direction you are rowing. The coefficient of drag between your boat and the water is 1.2, the area in contact with the water is 0.1 m2 and the density of the water is 1000 kg/m3. You are moving at a velocity of 4 m/s into a head wind of 4 m/s. Your coefficient of drag between you and the air is 1.4, the area in contact with the air is 0.4 m2 and the density of the air is 1.2 kg/m3. Your goal is to create a net force moving downstream that is equal to 100 N. How much force must you exert with the oar and in what direction to achieve this net force downstream?arrow_forwardThe Air Force's new experimental jet, the X - 9001, is a perfectly flat, rectangular wing. It has a cruising speed of 100 m s¹. Determine the thrust force required to maintain that speed [36 N]. Neglect any frontal area or pressure drag. Drag occurs on both the top and bottom of the plate. The plane may be considered to be 1 m long and 1 m wide.arrow_forwardA vertical air stream flowing at a velocity of 100 m/s supports a ball of 60 mm in diameter. Taking the density of air as 1.2 kg/m³ and kinematic viscosity as 1.6 stokes, the weight of the ball that is supported is (if coefficient of drag C= 0.8)arrow_forward
- A 7-ft-diameter spherical tank completely submerged in freshwater is being towed by a ship at 8 ft/s. Assuming turbulent flow, determine the required towing power.arrow_forwardAir flows at 10 m/s past a smooth rectangular flat plate 0.3m wide and 3m long. Assuming that the turbulence level in the oncoming stream is low and that transition occurs at Re- 5*105, calculate the ratio of total drag when the flow is parallel to the length of the plate to the value when the flow is parallel to the width take density 1.24 kg/m3 and v-0.15stoke.arrow_forwardA truck experiencing drag is able to reach a maximum velocity of v₁ = 30.5 m/s. It has cross-sectional area A₁ = 1.6 m^2 and coefficient of drag CD,1 = 0.86. The city is having a parade and you want to use your truck as a float. After fitting your truck with signs and posters, the new cross-sectional area is A₂ = 3.3 m^2, and the coefficient of drag has increased to CD,2 = 1.38. What is the new maximum speed of your truck? Give your answer to 1 decimal place. Assume the density of air is 1.204 kg/m^3 and does not change, and assume the accelerating force provided by the engine does not change. Backup link to image (opens in new tab). A₂arrow_forward
- You are pouring heavy syrup on your pancakes. As the syrup spreads over the pancake, would the thin film of syrup be a laminar or turbulent flow? Explain.arrow_forwardA wheel tractor has a 200HP engine.If the weight of the wheel tractor is 30 tons and the weight on the drivingwheels is 50% of this weight, and it is operating at an altitute of 1000m above sea level, at an average temperature of 25 degree celcius, and at an average speed of 12km/hr. What is the maximum available rimpull if thecoefficient of traction is 0.25?. Take rimpull efficiency as 85%arrow_forwardAn airplane has a rectangular wing with a chord length of 8 ft. If the airplane is flying at 200knots TAS and at 20,000 ft density altitude, find the Reynolds number at the trailing edge of the wing.arrow_forward
- A 30-cm-diameter smooth ball of density Phall = 210 kg/m³ is tied to an object on the bottom of a river as shown on the right. Determine the angle 0 when the speed of the river current is a. U = 1.66 m/s b. U = 0.13 m/s c. For which velocity, the drag coefficient is lower? Explain why? 30° Take the density and viscosity of water in the river Pwater = 1000 kg/m², µwater = 0.001 kg/m's. Neglect the weight of the cable and the drag on it. 400 200 100 80 60 40 20 10 0.8 0.6 0.4 0.2 0.08 0.06 2 4 68 10- 2 4 68 2 4 68 2 4 68 102 2 4 68 103 pvd 2 4 68 10 2 4 68 10 100 10 105 Reynolds number, Drag coefficient, Cparrow_forwardThe drag equation for the Gofaster 172 is: D = 0.0003v2A. D is drag in pounds; v is airspeed in feet/second; and A is aircraft frontal area in square feet. At maximum airspeed, D = 140 lbs. How much does max airspeed INCREASE if the fuselage is narrowed such that frontal area A is reduced from 16 ft2 to 14 ft2? Give the answer in ft/sec AND mph. drag is 140 lbs. at maximum airspeed, regardless of frontal area. the question is: what is the INCREASE in max airspeed, not what is the max airspeed.arrow_forwardThe thin ( 3 mm ) thick plastic panel shown in the figure is lowered from a ship to a construction site on the ocean floor. The plastic panel weighs ( 200 N ) in air and is lowered at a rate of ( 2 m/s ). Assuming the panel remains vertically oriented, calculate the tension force in the cable. Take ( ρ = 1000 kg/m3, ν = 1.31 * 10-6 m2/s ), and use; CDlam = 1.328 / ReL 1/2 CDturb = 0.072 / ReL 1/5 .arrow_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
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