A 15 cm x 20 cm hot surface at 85°C is to be cooled by attaching 4 cm long aluminum (k = 237 W/m-°C) fins of 2 mm x 2 mm square cross section. The temperature of surrounding medium is 25°C and the heat transfer coefficient on the surfaces can be taken to be 20 W/m²-°C. If it is desired to triple the rate of heat transfer from the bare hot surface, determine the number of fins that needs to be attached. plot the number of fins as a function of the increase in the heat loss by fins relative to no fin case (i.e., overall effectiveness of the fins) in the range of 1.5 to 5. Discuss the results.

A 15 cm x 20 cm hot surface at 85°C is to be cooled by attaching 4 cm long aluminum (k = 237 W/m-°C) fins of 2 mm x 2 mm square cross section. The temperature of surrounding medium is 25°C and the heat transfer coefficient on the surfaces can be taken to be 20 W/m²-°C. If it is desired to triple the rate of heat transfer from the bare hot surface, determine the number of fins that needs to be attached. plot the number of fins as a function of the increase in the heat loss by fins relative to no fin case (i.e., overall effectiveness of the fins) in the range of 1.5 to 5. Discuss the results.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.39P: 1.39 On a cold winter day, the outside wall of a home is exposed to an air temperature of when the...

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2. A 15-cm X 20-cm hot surface at 85°C is to be cooled by attaching 4 cm-long aluminum (k = 237 W/m-°C) fins of 2-mm X 2-mm square cross section. The temperature of surrounding medium is 25°C and the heat transfer coefficient on the surfaces can be taken to be 20 W/m2-°C. If it is desired to triple the rate of heat transfer from the bare hot surface, determine the number of fins that needs to be attached.