Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470501979
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 12, Problem 12.56P
The spectral, hemispherical absorptivity of an opaque surface is as shown.
What is the solar absorptivity,
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
ә
レ
Figure below shows a link mechanism in which the link OA rotates uniformly in an
anticlockwise direction at 10 rad/s. the lengths of the various links are OA=75 mm, OB-150 mm,
BC=150 mm, CD-300 mm. Determine for the position shown, the sliding velocity of D.
A
A
B
#
Space Diagram
o NTS (Not-to-Scale)
C
10
=--20125
735)
750 x2.01
اه
2
レ
Tanism in which the link OA mm. O
anticlockwise direction at 10 rad/s, the lengths of the various links are OA=75mm, OB=150mm,
BC=150mm,CD=300mm. Determine for the position shown, the sliding velocity of D.
A
A
Space Diagram
o NT$ (Not-to-Scale)
B
#
C
か
750 x2.01
165
79622
Ashaft fitted with a flywheel rotates at 300 rpm. and drives a machine. The torque
required to drive the machine varies in a cyclic manner over a period of 2 revolutions. The torque drops
from 20,000 Nm to 10,000 Nm uniformly during 90 degrees and remains constant for the following 180
degrees. It then rises uniformly to 35,000 Nm during the next 225 degrees and after that it drops to
20,000 in a uniform manner for 225 degrees, the cycle being repeated thereafter.
Determine the power required to drive the machine and percentage fluctuation in speed, if the driving
torque applied to the shaft is constant and the mass of the flywheel is 12 tonnes with radius of gyration of
500 mm. What is the maximum angular acceleration of the flywheel.
35,000
TNM
20,000
10,000
0
90
270
495
Crank angle 8 degrees
720
Chapter 12 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 12 - Consider an opaque horizontal plate that is well...Ch. 12 - A horizontal, opaque surface at a steady-state...Ch. 12 - The top surface of an L=5mmthick anodized aluminum...Ch. 12 - A horizontal semitransparent plate is uniformly...Ch. 12 - What is the irradiation at surfaces A2 , A3 , and...Ch. 12 - According to its directional distribution, solar...Ch. 12 - Solar radiation incident on the earth’s surface...Ch. 12 - On an overcast day the directional distribution of...Ch. 12 - During radiant heat treatment of a thin-film...Ch. 12 - A small radiant heat source of area A1=2x104m2...
Ch. 12 - Determine the fraction of the total, hemispherical...Ch. 12 - The spectral distribution of the radiation emitted...Ch. 12 - Consider a 5-mm-square, diffuse surface A0 having...Ch. 12 - Assuming blackbody behavior, determine the...Ch. 12 - The dark surface of a ceramic stove top may be...Ch. 12 - The energy flux associated with solar radiation...Ch. 12 - A small flat plate is positioned just beyond the...Ch. 12 - A spherical aluminum shell of inside diameter D=2m...Ch. 12 - The extremely high temperatures needed to trigger...Ch. 12 - An enclosure has an inside area of 100m2 , and its...Ch. 12 - Assuming the earth’s surface is black, estimate...Ch. 12 - A proposed method for generating electricity from...Ch. 12 - Approximations to Planck’s law for the spectral...Ch. 12 - Estimate the wavelength corresponding to maximum...Ch. 12 - A furnace with a long, isothermal, graphite tube...Ch. 12 - Isothermal furnaces with small apertures...Ch. 12 - For materials A and B, whose spectral...Ch. 12 - A small metal object, initially at Ti=1000K ,is...Ch. 12 - The directional total emissivity of nonmetallic...Ch. 12 - Consider the metallic surface of Example 12.7....Ch. 12 - The spectral, directional emissivity of a diffuse...Ch. 12 - Consider the directionally selective surface...Ch. 12 - A sphere is suspended in air in a dark room and...Ch. 12 - Estimate the total, hemispherical emissivity for...Ch. 12 - Sheet steel emerging from the hot roll section of...Ch. 12 - A large body of nonluminous gas at a temperature...Ch. 12 - An opaque surface with the prescribed spectral,...Ch. 12 - The spectral reflectivity distribution for white...Ch. 12 - A diffuse, opaque surface at 700 K has spectral...Ch. 12 - The spectral, hemispherical absorptivity of an...Ch. 12 - The spectral, hemispherical absorptivity of an...Ch. 12 - Consider an opaque, diffuse surface for which the...Ch. 12 - Radiation leaves a furnace of inside surface...Ch. 12 - The spectral transmissivity of a 1-mm-thick layer...Ch. 12 - The spectral transmissivity of plain and tinted...Ch. 12 - Referring to the distribution of the spectral...Ch. 12 - The spectral absorptivity and spectral...Ch. 12 - Consider a large furnace with opaque, diffuse,...Ch. 12 - Four diffuse surfaces having the spectral...Ch. 12 - The spectral transmissivity of a 50m -thick...Ch. 12 - An opaque, horizontal plate has a thickness of...Ch. 12 - Two small surfaces, A and B, are placed inside an...Ch. 12 - Consider an opaque, diffuse surface whose spectral...Ch. 12 - The 50-mm peephole of a large furnace operating at...Ch. 12 - The window of a large vacuum chamber is fabricated...Ch. 12 - A thermograph is a device responding to the...Ch. 12 - A radiation thermometer is a radiometer calibrated...Ch. 12 - A radiation detector has an aperture of area...Ch. 12 - A small anodized aluminum block at 35C is heated...Ch. 12 - Consider the diffuse, gray opaque disk A1 , which...Ch. 12 - A two-color pyrometer is a device that is used to...Ch. 12 - An apparatus commonly used for measuring the...Ch. 12 - A procedure for measuring the thermal conductivity...Ch. 12 - One scheme for extending the operation of gas...Ch. 12 - The equipment for heating a wafer during a...Ch. 12 - Neglecting the effects of radiation absorption,...Ch. 12 - Consider the evacuated tube solar collector...Ch. 12 - Solar flux of 900W/m2 is incident on the top side...Ch. 12 - Consider an opaque, gray surface whose directional...Ch. 12 - A contractor must select a roof covering material...Ch. 12 - It is not uncommon for the night sky temperature...Ch. 12 - Plant leaves possess small channels that connect...Ch. 12 - In the central receiver concept of solar energy...Ch. 12 - Radiation from the atmosphere or sky can be...Ch. 12 - A thin sheet of glass is used on the roof of a...Ch. 12 - Growers use giant fans to prevent grapes from...Ch. 12 - A circular metal disk having a diameter of 0.4 m...Ch. 12 - The neighborhood cat likes to sleep on the roof of...Ch. 12 - The exposed surface of a power amplifier for an...Ch. 12 - Consider a thin opaque, horizontal plate with an...Ch. 12 - The oxidized-aluminum wing of an aircraft has a...Ch. 12 - Two plates, one with a black painted surface and...Ch. 12 - A radiator on a proposed satellite solar power...Ch. 12 - A radiator on a proposed satellite solar power...Ch. 12 - A spherical satellite in near-earth orbit is...Ch. 12 - An annular fin of thickness t is used as a...Ch. 12 - The directional absorptivity of a gray surface...Ch. 12 - Two special coatings are available for application...Ch. 12 - Consider the spherical satellite of Problem...Ch. 12 - A spherical capsule of 3-m radius is fired from a...Ch. 12 - Consider the spherical satellite of Problem...Ch. 12 - A solar panel mounted on a spacecraft has an area...Ch. 12 - It is known that on clear nights a thin layer of...Ch. 12 - A shallow layer of water is exposed to the natural...Ch. 12 - A roof-cooling system, which operates by...Ch. 12 - A wet towel hangs on a clothes line under...Ch. 12 - Our students perform a laboratory experiment to...
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
- Figure below shows a link mechanism in which the link OA rotates uniformly in an anticlockwise direction at 10 rad/s. the lengths of the various links are OA=75 mm, OB-150 mm, BC=150 mm, CD-300 mm. Determine for the position shown, the sliding velocity of D. A 45 B Space Diagram o NTS (Not-to-Scale) C Darrow_forwardmotion is as follows; 1- Dwell 45°. Plot the displacement diagram for a cam with flat follower of width 14 mm. The required 2- Rising 60 mm in 90° with Simple Harmonic Motion. 3- Dwell 90°. 4- Falling 60 mm for 90° with Simple Harmonic Motion. 5- Dwell 45°. Then design the cam profile to give the above displacement diagram if the minimum circle diameter of the cam is 50 mm.arrow_forwardAn ideal gas, occupying a volume of 0.02 m3 , has a temperature of 25 0C and is at 1.2 bar. The gas is compressed reversibly and adiabatically to a final pressure of 8 bar. Assuming the gas has an adiabatic index of γ = 1.4, calculate (a) the final temperature, (b) the final volume, (c) the work performed during the compression and (d) the heat transferred.arrow_forward
- attached is a past paper question in which we werent given the solution. a solution with clear steps and justification would be massively appreciated thankyou.arrow_forwardin this scenario, when it comes to matrix iterations it states this system is assumed out of phase. why is this?arrow_forwardQ1. A curved beam of a circular cross section of diameter "d" is fixed at one end and subjected to a concentrated load P at the free end (Fig. 1). Calculate stresses at points A and C. Given: P = 800 N, d = 30 mm, a 25 mm, and b = 15 mm. Fig.1 P b B (10 Marks)arrow_forward
- You are working as an engineer in a bearing systems design company. The flow of lubricant inside a hydrodynamic bearing (p = 0.001 kg m-1 s-1) can be approximated as a parallel, steady, two-dimensional, incompressible flow between two parallel plates. The top plate, representing the moving part of the bearing, travels at a constant speed, U, while the bottom plate remains stationary (Figure Q1). The plates are separated by a distance of 2h = 1 cm and are W = 20 cm wide. Their length is L = 10 cm. By applying the above approximations to the Navier-Stokes equations and assuming that end effects can be neglected, the horizontal velocity profile can be shown to be y = +h I 2h = 1 cm x1 y = -h u(y) 1 dP 2μ dx -y² + Ay + B moving plate stationary plate U 2 I2 L = 10 cm Figure Q1: Flow in a hydrodynamic bearing. The plates extend a width, W = 20 cm, into the page.arrow_forwardQuestion 1 You are working as an engineer in a bearing systems design company. The flow of lubricant inside a hydrodynamic bearing (µ = 0.001 kg m¯¹ s¯¹) can be approximated as a parallel, steady, two-dimensional, incompressible flow between two parallel plates. The top plate, representing the moving part of the bearing, travels at a constant speed, U, while the bottom plate remains stationary (Figure Q1). The plates are separated by a distance of 2h = 1 cm and are W = 20 cm wide. Their length is L = 10 cm. By applying the above approximations to the Navier-Stokes equations and assuming that end effects can be neglected, the horizontal velocity profile can be shown to be 1 dP u(y) = 2μ dx -y² + Ay + B y= +h Ꮖ 2h=1 cm 1 x1 y = −h moving plate stationary plate 2 X2 L = 10 cm Figure Q1: Flow in a hydrodynamic bearing. The plates extend a width, W = 20 cm, into the page. (a) By considering the appropriate boundary conditions, show that the constants take the following forms: U U 1 dP A =…arrow_forwardQuestion 2 You are an engineer working in the propulsion team for a supersonic civil transport aircraft driven by a turbojet engine, where you have oversight of the design for the engine intake and the exhaust nozzle, indicated in Figure Q2a. The turbojet engine can operate when provided with air flow in the Mach number range, 0.60 to 0.80. You are asked to analyse a condition where the aircraft is flying at 472 m/s at an altitude of 14,000 m. For all parts of the question, you can assume that the flow path of air through the engine has a circular cross section. (a) ← intake normal shock 472 m/s A B (b) 50 m/s H 472 m/s B engine altitude: 14,000 m exhaust nozzle E F exit to atmosphere diameter: DE = 0.30 m E F diameter: DF = 0.66 m Figure Q2: Propulsion system for a supersonic aircraft. a) When the aircraft is at an altitude of 14,000 m, use the International Standard Atmosphere in the Module Data Book to state the local air pressure and tempera- ture. Thus show that the aircraft speed…arrow_forward
- يكا - put 96** I need a detailed drawing with explanation or in wake, and the top edge of im below the free surface of the water. Determine the hydrothed if hydrostatic on the Plot the displacement diagram for a cam with roller follower of diameter 10 mm. The required motion is as follows; 1- Rising 60 mm in 135° with uniform acceleration and retardation motion. 2- Dwell 90° 3- Falling 60 mm for 135° with Uniform acceleration-retardation motion. Then design the cam profile to give the above displacement diagram if the minimum circle diameter of the cam is 50 mm. =--20125 7357 750 X 2.01arrow_forwardYou are working as an engineer in a bearing systems design company. The flow of lubricant inside a hydrodynamic bearing (µ = 0.001 kg m¯¹ s¯¹) can be approximated as a parallel, steady, two-dimensional, incompressible flow between two parallel plates. The top plate, representing the moving part of the bearing, travels at a constant speed, U, while the bottom plate remains stationary (Figure Q1). The plates are separated by a distance of 2h = 1 cm and are W = 20 cm wide. Their length is L = 10 cm. By applying the above approximations to the Navier-Stokes equations and assuming that end effects can be neglected, the horizontal velocity profile can be shown to be U y = +h У 2h = 1 cm 1 x1 y=-h u(y) = 1 dP 2μ dx -y² + Ay + B moving plate - U stationary plate 2 I2 L = 10 cm Figure Q1: Flow in a hydrodynamic bearing. The plates extend a width, W = 20 cm, into the page. (a) By considering the appropriate boundary conditions, show that the constants take the following forms: A = U 2h U 1 dP…arrow_forwardQuestion 2 You are an engineer working in the propulsion team for a supersonic civil transport aircraft driven by a turbojet engine, where you have oversight of the design for the engine intake and the exhaust nozzle, indicated in Figure Q2a. The turbojet engine can operate when provided with air flow in the Mach number range, 0.60 to 0.80. You are asked to analyse a condition where the aircraft is flying at 472 m/s at an altitude of 14,000 m. For all parts of the question, you can assume that the flow path of air through the engine has a circular cross section. (a) normal shock 472 m/s A B (b) intake engine altitude: 14,000 m D exhaust nozzle→ exit to atmosphere 472 m/s 50 m/s B diameter: DE = 0.30 m EX diameter: DF = 0.66 m Figure Q2: Propulsion system for a supersonic aircraft. F a) When the aircraft is at an altitude of 14,000 m, use the International Standard Atmosphere in the Module Data Book to state the local air pressure and tempera- ture. Thus show that the aircraft speed of…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
Understanding Thermal Radiation; Author: The Efficient Engineer;https://www.youtube.com/watch?v=FDmYCI_xYlA;License: Standard youtube license