Heat and Mass Transfer: Fundamentals and Applications
6th Edition
ISBN: 9781260440058
Author: CENGEL, Yunus
Publisher: MCGRAW-HILL HIGHER EDUCATION
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Chapter 3, Problem 128P
Consider a very long rectangular fin attached to a flat surface such that the temperature at the end of the fm is essentially that of the surrounding air. i.e.. 20°C. Its width is 5.0 cm; thickness is 1.0 mm; thermal conductivity is 200 W/m.K; and base temperature is 40°C. The heat transfer coefficient is 20 W/m2 K. Estimate the fin temperature at a distance of 5.0 cm from the base and the rate of heat loss from the entire fin.
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A total of 10 rectangular aluminum fins (k = 203 W/m-K) are placed on the outside flat surface of an electronic device. Each fin is 100 mm wide, 20 mm high and 4 mm thick. The fins are located parallel to each other at a center-to center distance of 8 mm. The temperature at the outside surface of the electronic device is 60°C. The air is at 20°C, and the heat transfer coefficient is 100 W/m? ‘K. Determine (a) the rate of heat loss from the electronic device to the surrounding air and (b) the fin effectiveness.
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Q3/
Circular fin of rectangular profile is attached to a 3.0-cm-diameter tube maintained at 100°C.
The outside diameter of the fin is 9.0 cm and the fin thickness is 1.0 mm. The environment has a
convection coefficient of 50 W/m2. °C and a temperature of 30°C. Calculate the thermal
conductivity of the material for a fin efficiency of 60 percent.
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Chapter 3 Solutions
Heat and Mass Transfer: Fundamentals and Applications
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A and B, with the same surface...Ch. 3 - Prob. 218PCh. 3 - A room at 20C air temperature is losing heat to...Ch. 3 - Prob. 220PCh. 3 - A 1-cm-diameter, 30cm-long fin made of aluminum...Ch. 3 - A hot surface at 80C in air at 20C is to be cooled...Ch. 3 - A cylindrical pin fin of diameter 0.6 cm and...Ch. 3 - A 3-cm-long. 2-nuti x 2-mm rectangular...Ch. 3 - Two finned surfaces with long fins are identical,...Ch. 3 - A 20-cm-diameter hot sphere at 120C is buried in...Ch. 3 - A 25-cm-diameter, 2.4-rn-long vertical cylinder...Ch. 3 - Prob. 228PCh. 3 - The walls of a food storage facility are made of a...Ch. 3 - The equivalent thermal resistance for the thermal...Ch. 3 - Prob. 231PCh. 3 - Prob. 232PCh. 3 - Prob. 233PCh. 3 - The fin efficiency is defined as the ratio of the...Ch. 3 - Prob. 235PCh. 3 - In the United States, building insulation is...Ch. 3 - Prob. 237PCh. 3 - A plane brick wall (k=0.7W/m.K) and is 10 cm...Ch. 3 - The temperature in deep space is close to absolute...Ch. 3 - In the design of electronic components, it is...Ch. 3 - Using cylindrical samples of the same material,...Ch. 3 - Find out about the wall construction of the cabins...Ch. 3 - Prob. 243PCh. 3 - A house with 200-m2 floor space is to be heated...
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