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 57P
The forming section of a plastics plant puts out a continuous sheet of plastic that is 1.2 in wide and 2 mm thick at a rate of 18 m/min. The sheet is subjected to airflow at a velocity of 4 m/s on both top and bottom surfaces normal to the direction of motion of the sheet. The width of the air cooling section is such that a fixed point on the plastic sheet passes through that section in 2 s. Using properties of air at 1 atm and
Figure 11.57
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
The forming section of a plastics plant puts out a continuous sheet of plastic that is 1.2 m wide and 2 mm thick at a rate of 18 m/min. The sheet is subjected to airflow at a velocity of 4 m/s on both top and bottom surfaces normal to the direction of motion of the sheet. The width of the air cooling section is such that a fixed point on the plastic sheet passes through that section in 2 s. Using properties of air at 1 atm and 60°C, determine the drag force the air exerts on the plastic sheet in the direction of airflow.
Example 3: Air at 27◦C and 1 atm flows over a flat plate at a speed of 2 m/s. Assume that the plate is heated over its entire length to a temperature of 60◦C. Calculate the heat transferred in (a) the first 20 cm of the plate and (b) the first 40 cm of the plate.
Air at 20oC (density = 1.204 kg/m3) flows towards a rotating cylinder of diameter 1.50 m. If the velocity of the air is 100 km/h and the cylinder rotates clockwise at 220 rpm, determine
(c) the maximum velocity of the air around the rotor, and
(d) the pressure coefficient at the location corresponding to the maximum velocity.
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
- A sphere of diameter 10 mm and density 7700 kg/ m3 falls under gravity at terminal conditions through a liquid of density 900 kg/ m3 in a tube of diameter 12 mm. After reaching terminal velocity, the ball falls 5 cm in 31.3 seconds. Using the Francis wall correction factor: fw = (1-x/D)2.25 where x is the particle diameter and D is the diameter of the tube and fw is the wall factor (the velocity in the tube / velocity in an infinitely large tube), determine the: a) viscosity (Pa s) of the fluid if Stokes law applies (Correct Answers: 4.118) b) Reynolds number if the fluid viscosity is given in the previous part (Correct Answers: 0.1967) c) minimum viscosity where the Re <= 0.3 (Correct Answers: 2.7) I need help with the steps! Please helparrow_forwardIn a glass production process, a glass plate of 0.5 m x 2 m and 3 mm thickness is cooled by air blown at a speed of 1 m/s from both sides. Air is blown parallel to the plate. The initial temperature of the glass plate is 425 C and the temperature of the air is 200 C. Calculate the temperature of the plate after cooling for 5 minutes. Properties of glass = 2500 kg/m3, c = 7600 J/kgK, k = 0.8 W/mKproperties of airarrow_forwardThe fluid condition at the inlet and exit of a horizontal convergent nozzle is analysed. The nozzle is operating steadily and heat loss is assumed negligible. If the specific enthalpy of fluid and velocity of fluid at the inlet are 3,314 kJ/kg and 226 km/hr respectively. At the exit the specific enthalpy of fluid is 2,563 J/kg. Calculate the exit area (in mm-)of the nozzle when the specific volume at the nozzle exit is 0.61 m3/kg at the inlet area of 0.23 m2 and the specific volume at the inlet is 0.3 m3/kg.arrow_forward
- 3. A natural gas is flowing through a long distance smooth pipeline (1 m in diameter) at a constant temperature. The gas enters the pipeline at a velocity of 12 m s-1 and at the temperature and pressure of 20 °C and 690 kPa, respectively. Compressors and coolers are provided every 15 km along the pipeline to recompress and cool the gas to its initial temperature and pressure. Calculate the theoretical power requirement to compress the gas by each compressor. Assume that the compression is an adiabatic frictionless process and the work done by the compressor on unit mass of gas is given by: AW = Pout vdP [J kg-¹] Pin where Pin and Pout are the pressures at the inlet and outlet of the compressor, respectively, and vis the specific volume of gas. Hint: see Coulson and Richardson, Volume 1, Section 8.3.4, page 347-351. Specific heat ratio y (= C₂/C₂) = 1.3 [Ans. 845631 W]arrow_forwardYou are conducting a series of flow experiments in order to investigate flow across a horizontal flat plate. When water at 51.9°C flows across a flat plate, the distance from the front edge of the plate to where the transition from laminar to turbulent flow occurs is determined to be 314mm. 1. What is the bulk velocity of the water flowing over the plate? 2. If the experiment is done with Refrigerant-22 instead of water and the same distance from the edge is measured, what would the bulk velocity be? 3. Compare the velocity and thermal boundary layer thickness at the laminar/turbulent transition point of the two cases above and comment on your finding. 4. Based on the average convective heat transfer coefficient up to the laminar/turbulent transition distance, which fluid would yield a higher heat transfer rate under the specified conditions?arrow_forwardThere is a flow of air that circulates over a flat plate that is used to store a food product at a temperature of 95 ° C throughout its surface. The air flows at a speed of 2.5 m/s and has a temperature of 25.0°C. The plate measures 600.0 mm · 300.00 mm. As a task assigned by your plant operations manager, you are asked to answer the following questions: i. Determine the heat loss from the plate if the air flows parallel to the 600.00-mm side.ii. How would this heat loss be affected if the airflow is made parallel to the 300.0-mm side? For this type of configuration, the coefficient of heat transfer by forced convection, h, can be obtained from the relation IMAGE BELOW The previous correlation is valid for the laminar regime, that is: Re < 500000arrow_forward
- The fluid condition at the inlet and exit of a horizontal convergent nozzle is analysed. The nozzle is operating steadily. and heat loss is assumed negligible. If the specific enthalpy of fluid and velocity of fluid at the inlet are 3,089 kJ/kg and 229 km/hr respectively. At the exit the specific enthalpy, of fluid is 2,569 J/kg. Calculate the exit area (in mm2)of the nozzle when the specific volume at the 3 nozzle exit is 0.63 m/kg at the inlet area of 0.2 m2 and the specific volume at the inlet is 0.31 m3/kg. You do not need to include the unit for this question.arrow_forwardA plate with a negligible thickness of 50 cm in width and 100 cm in length and from its upper surface, it is exposed to 2 different airflows in the same direction along its length. top of the sheet The speed of the air flowing from its surface is 3600 m/min and its temperature is 473 K. Its temperature is 298 K and its speed is 600 m/min. The total heat exchange between both fluids calculate. (Assume the initial temperature of the plate is 160⁰C.)arrow_forwardThe fluid condition at the inlet and exit of a horizontal convergent nozzle is analysed. The nozzle is operating steadily and heat loss is assumed negligible. If the specific enthalpy of fluid and velocity of fluid at the inlet are 3,351 kJ/kg and 298 km/hr respectively. At the exit the specific enthalpy of fluid is 2,619 J/kg. Calculate the exit area (in mm2)of the nozzle when the specific volume at the nozzle exit is 0.61 m3/kg at the inlet area of 0.23 m2 and the specific volume at the inlet is 0.33 m3/kg. You do not need to include the unit for this question.arrow_forward
- As shown in the figure, electrical heaters operating in the V-220 V are placed on the lower surface of the square-shaped horizontal aluminum plate with a length and width of 1.2 m. Air at a temperature of 27 °C flows from the upper surface of the plate in parallel at 15 m/s. Since the bottom surface of the plate is fully insulated, what should the value of the current () passing through the electrical elements be so that the temperature of the plate does not exceed 77 °C? Air Al plate Heaters L=1.2 marrow_forwardWind flows over a flat plate of length L = 25 mm and width W = 8 mm. The plate is maintained at a constant temperature of 32 °C on both sides. using an electric heater generating heat at a rate of Q = 0.5 W which is dissipated to air from both sides of the plate. Consider the temperature of the wind/air as 20 °C and assume that the wind speed does not exceed 100 m/s. The properties of air at this temperature are given as; specific heat capacity Cp = 1.005 kJ/kg-K, thermal conductivity k = 0.0253 W/m-K, Density p = 1.19 kg/m³, and kinematic viscosity v = 1.522 x 10 5 m²/s.arrow_forwardSketch the velocity gradients that arise from pressure-driven flow for a Newtonian liquid and a shear thinning liquid.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
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license