Fundamentals of Heat and Mass Transfer
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
bartleby

Videos

Textbook Question
Chapter 1, Problem 1.45P

An aluminum plate 4 mm thick is mounted in a horizontal position, and its bottom surface ¡s well insulated. A special, thin coating is applied to the top surface such that it absorbs 80% of any incident solar radiation, while having an emissivity of 0.25. The density ρ and specific heat c of aluminum are known to be 2700 Kg / m 3 and 900 J/Kg K , respectively.
(a) Consider conditions for which the plate ¡s at a temperature of 25°C and its top surface is suddenly exposed to ambient air at T = 20 ° C and to solar radiation that provides an incident flux of 900 W / m 2 . The convection heat transfer coefficient between the surface and the air is h = 20 W / m 2 K . What ¡s the initial rate of change of the plate temperature?
(b) What will be the equilibrium temperature of the plate when steady-state conditions are reached?
(c) The surface radiative properties depend on the specific nature of the applied coating. Compute and plot the steady-state temperature as a function of the emissivity for 0.05 1 , with all other conditions remaining as prescribed. Repeat your calculations for values of α s = 0.5 and 1.0, and plot the results with those obtained for α s = 0.8 . If the intent is to maximize the plate temperature, what is the most desirable combination of the plate emissivity and its absorptivity to solar radiation?

Blurred answer
Students have asked these similar questions
The emissivity of galvanized steel sheet, a common roofing material, is ε = 0.13 at temperatures around 300 K, while its absorptivity for solar irradiation is αS = 0.65. Would the neighborhood cat be comfortable walking on a roof constructed of the material on a day when GS = 750 W/m2, T∞ = 16°C, and h = 7 W/m2 · K? Assume the bottom surface of the steel is insulated.
A spherical interplanetary probe of 0.5-m diameter contains electronics that dissipate 150 W. If the probe surface has an emissivity of 0.8 and the probe does not receive radiation from other surfaces, as, for example, from the sun, what is its surface temperature?
A group of 25 power transistors, dissipating 1.5 W each, are to be cooled by attaching them to a black-anodized square aluminum plate and mounting the plate on the wall of a room at 30°C. The emissivity of the transistor and the plate surfaces is 0.9. Assuming the heat transfer from the back side of the plate to be negligible and the temperature of the surrounding surfaces to be the same as the air temperature of the room, determine the size of the plate if the average surface temperature of the plate is not to exceed 50°C.

Chapter 1 Solutions

Fundamentals of Heat and Mass Transfer

Ch. 1 - The heat flux that is applied to one face of a...Ch. 1 - An inexpensive food and beverage container is...Ch. 1 - What is the thickness required of a masonry wall...Ch. 1 - A wall is made from an inhomogeneous...Ch. 1 - The 5-mm-thick bottom of a 200-mm-diameter panmay...Ch. 1 - A square silicon chip (k=150W/mK) is of width...Ch. 1 - For a boiling process such as shown in Figure 1.5...Ch. 1 - You’ve experienced convection cooling if you’ve...Ch. 1 - Air at 40°C flows over a long, 25-mm-diameter...Ch. 1 - A wall has inner and outer surface temperatures of...Ch. 1 - An electric resistance heater is embedded in a...Ch. 1 - The free convection heat transfer coefficient on a...Ch. 1 - A transmission case measures W=0.30m on a sideand...Ch. 1 - A cartridge electrical heater is shaped as a...Ch. 1 - A common procedure for measuring the velocity of...Ch. 1 - A square isothermal chip is of width w=5mm on...Ch. 1 - The temperature controller for a clothes dryer...Ch. 1 - An overhead 25-m-long, uninsulated industrial...Ch. 1 - Under conditions for which the same room...Ch. 1 - A spherical interplanetary probe of 0.5-m diameter...Ch. 1 - An instrumentation package has a spherical outer...Ch. 1 - Consider the conditions of Problem 1.22. However,...Ch. 1 - If TsTsur in Equation 1.9, the radiation heat...Ch. 1 - A vacuum system, as used ¡n sputtering...Ch. 1 - An electrical resistor is connected to a battery,...Ch. 1 - Pressurized water (pin=10bar,Tin=110C) enters...Ch. 1 - Consider the tube and inlet conditions of Problem...Ch. 1 - An internally reversible refrigerator has a...Ch. 1 - A household refrigerator operates with cold-...Ch. 1 - Chips of width L=15mm on a side are mounted to...Ch. 1 - Consider the transmission case of Problem 1...Ch. 1 - One method for growing thin silicon sheets for...Ch. 1 - Heat is transferred by radiation and convection...Ch. 1 - Radioactive wastes are packed in a long,...Ch. 1 - An aluminum plate 4 mm thick is mounted in a...Ch. 1 - A blood warmer is to be used during the...Ch. 1 - Consider a carton of milk that is refrigerated at...Ch. 1 - Prob. 1.48PCh. 1 - Liquid oxygen, which has a boiling into of 90 K...Ch. 1 - The emissivity of galvanized steel sheet, a...Ch. 1 - Three electric resistance heaters of length...Ch. 1 - A hair dryer may be idealized as a circular duct...Ch. 1 - In one stage of an annealing process, 304...Ch. 1 - Convection ovens operate on the principle of...Ch. 1 - Annealing, an important step ¡n semiconductor...Ch. 1 - In the thermal processing of semiconductor...Ch. 1 - A furnace tor processing semiconductor materials...Ch. 1 - Prob. 1.58PCh. 1 - Consider the wind turbine of Example 1.3. To...Ch. 1 - Consider the conducting rod of Example 1.4...Ch. 1 - A long bus bar (cylindrical rod used for making...Ch. 1 - A 50mm45mm20mm cell phone chargerhas a surface...Ch. 1 - A spherical, stainless steel (AISI 302) canister...Ch. 1 - A freezer compartment is covered with a...Ch. 1 - A vertical slab of Wood’s metal is joined to a...Ch. 1 - A photovoltaic panel of dimension 2m4m isinstalled...Ch. 1 - Following the hot vacuum forming of a...Ch. 1 - Prob. 1.69PCh. 1 - A computer consists of an array of five printed...Ch. 1 - Prob. 1.71PCh. 1 - The roof of a car in a parking lot absorbs a solar...Ch. 1 - Consider the conditions of Problem 1.22,but the...Ch. 1 - Most of the energy we consume as food ¡s converted...Ch. 1 - Prob. 1.75PCh. 1 - The wall of an oven used to cure plastic parts is...Ch. 1 - An experiment to determine the convection...Ch. 1 - A thin electrical heating element provides a...Ch. 1 - A rectangular forced air healing duct is suspended...Ch. 1 - Consider the steam pipe of Example 1.2. The...Ch. 1 - During its manufacture, plate glass at 600°C is...Ch. 1 - The curing press of Example 1.9 involves exposure...Ch. 1 - The diameter and surface emissivity of an...Ch. 1 - Prob. 1.84PCh. 1 - A solar flux of 700W/m2K is incident on a...Ch. 1 - In considering the following problems involving...
Knowledge Booster
Mechanical Engineering
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
  • 1.1 On a cold winter day, the outer surface of a 0.2-m-thick concrete wall of a warehouse is exposed to temperature of –5°C, while the inner surface is kept at 20°C. The thermal conductivity of the concrete is 1.2 W/m K. Determine the heat loss through the wall, which is 10-m long and 3-m high. Problem 1.1
    2.3 The shield of a nuclear reactor is idealized by a large 25-cm-thick flat plate having a thermal conductivity of . Radiation from the interior of the reactor penetrates the shield and there produces heat generation that decreases exponentially from a value of at the inner surface to a value of at a distance of 12.5 cm from the interior surface. If the exterior surface is kept at 38°C by forced convection, determine the temperature at the inner surface of the field. Hint: First set up the differential equation for a system in which the heat generation rate varies according to .
    An inventor wants to increase the efficiency of wood-burning stoves by reducing the energy lost through the exhaust stack. he proposes to accomplish this by attaching fins to the outer surface of the chimney, as shown schematically on the picture. the fins are attached circumferentially to the stack, having a base of 0,5cm, 2cm long perpendicular to the surface, and 6cm long in the vertical direction. the surface temperature of the stack is 500 C and the surrounding temperature is 20 C for this initial thermal design, assume that each fin loses heat by natural convection with a convection heat transfer coefficient of 10W/m^2 K. select a suitable material for the fin and discuss the manner of attachment as well as the effect of contact resistance
    Recommended textbooks for you
  • Principles of Heat Transfer (Activate Learning wi...
    Mechanical Engineering
    ISBN:9781305387102
    Author: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