Question

Lecture Assignment #7 A heat sink is composed of an array of rectangular fins. h-63 W/m-K T 35°C a=2 mm b-2 mm FL-14 mm W-24 cm th, 0.75 cm k-35 W/m-K p 8200 kg/m The heat sink is square with base side dimension W 24 cm and base thickness ths- 0.75 cm. The fins are square and have side dimension a 2 mm and length L 14 mm. Fins are separated by a distance b 2 mm. (Note that there are more than the 16 fins shown in figure on the heat sink). The fin and base material have conductivity k 35 W/m-K. The heat transfer coefficient between the surface and the air is h- 63 W/m2-K. The ambient air is at Te 35°C. a.) Determine the efficiency of the fins. b.) Draw a resistance network that extends from the underside of the heat sink to the ambient air. c.) Calculate the values of each of the resistances in your network from (b) and the total resistance of the heat sink. d.) Plot the temperature at the underside of the heat sink as a function of the rate of heat transfer between 0 and 2 kW to the heat sink

Answer 1

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