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
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Textbook Question
Chapter 4, Problem 4S.7P
Hollow prismatic bars fabricated from plain carbon steel are 1 m long with top and bottom surfaces, as well as both ends. well insulated. For each bar. find the shape factor and the heat rate per unit length of the bar when
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Example 7.9:
A one meter long metal rod is thermally insulated in its circumference. The terminal temperatures of the rod are measured to be 100C and 20C as illustrated in the figure below. Determine the heat fluxes in the rod. The rod is made of two different materials of copper and aluminum.
Calculate the heat loss per foot from a 10 in. nominal pipe ( outside diameter = 10.75 in.) covered with a composite pipe insulation consisting of 1 ½ in of insulation A placed next to the pipe and 2 in. of insulation B placed upon insulation A. Assume that the inner and outer surface temperature of the composite insulation are 700°F and 110°F respectively , and that the thermal conductivity of material I is 0.05 Btu/ hr-ft-°F and for material II is 0.039 Btu/hr-ft-°F (Include illustration/Figure)
A steel rod, 12 mm in diameter, passes centrally through a copper tube 2.5 m long and having 36 mm and 48 mm as internal and external diameters respectively. The tube is closed at each end by 24 mm thick steel plates which are secured by nuts. The nuts are tightened until the copper tube is reduced in length by 0.50. The whole assembly is then raised in temperature by 60 degrees Celsius. Steel: Coefficient of expansion = 1.2x10^-5/degrees Celsius, Es = 200 GPa Copper: Coefficient of expansion = 1.75x10^-5/degrees Celsius, Ec = 100 GPa
Calculate the stress in copper and stress in steel after the rise of temperature if the thickness of the plates remains unchanged. Indicate if the answer is tensile, tension, compression.
Chapter 4 Solutions
Fundamentals of Heat and Mass Transfer
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