A 50-cm x 50-cm circuit board that contains 121 square chips on one side is to be cooled by combined natural convection and radiation by mounting it on a horizontal surface in a room at 25°C. Each chip dissipates 0.18 W of power, and the emissivity of the chip surfaces is 0.7. Assume the heat transfer from the back side of the circuit board to be negligible, and the temperature of the surrounding surfaces to be the same as the air temperature of the room. Evaluate air properties at a film temperature of 30°C and 1 atm pressure. Given: The properties of air at 1 atm and the anticipated film temperature of 30°C. k = 0.02588 W/m.°C, v=1.608 x 10-5 m²/s, Pr = 0.7282, 3= 0.0033 K-1 Assuming the circuit board to be positioned horizontally with chips facing up, determine the surface temperature of the chips. The surface temperature of the chips is 36.2 * °C.

A 50-cm x 50-cm circuit board that contains 121 square chips on one side is to be cooled by combined natural convection and radiation by mounting it on a horizontal surface in a room at 25°C. Each chip dissipates 0.18 W of power, and the emissivity of the chip surfaces is 0.7. Assume the heat transfer from the back side of the circuit board to be negligible, and the temperature of the surrounding surfaces to be the same as the air temperature of the room. Evaluate air properties at a film temperature of 30°C and 1 atm pressure. Given: The properties of air at 1 atm and the anticipated film temperature of 30°C. k = 0.02588 W/m.°C, v=1.608 x 10-5 m²/s, Pr = 0.7282, 3= 0.0033 K-1 Assuming the circuit board to be positioned horizontally with chips facing up, determine the surface temperature of the chips. The surface temperature of the chips is 36.2 * °C.

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.

Chapter11: Heat Transfer By Radiation

Section: Chapter Questions

Problem 11.48P

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