A 15 cm x 15 cm circuit board dissipating 15 W of power uniformly is cooled by air, which approaches the circuit board at 20°C with a velocity of 5 m/s. Disregard any heat transfer from the back surface of the board and evaluate properties of air at 300 K. Assume the flow to be turbulent across the entire length of the board since the electric components will have tripped the boundary layer. (a) Determine the surface temperature of the electronic components at the leading edge of the board, and (b) at the end of the board. (c) Ideally, at what temperature would the properties of air be evaluated at?

A 15 cm x 15 cm circuit board dissipating 15 W of power uniformly is cooled by air, which approaches the circuit board at 20°C with a velocity of 5 m/s. Disregard any heat transfer from the back surface of the board and evaluate properties of air at 300 K. Assume the flow to be turbulent across the entire length of the board since the electric components will have tripped the boundary layer. (a) Determine the surface temperature of the electronic components at the leading edge of the board, and (b) at the end of the board. (c) Ideally, at what temperature would the properties of air be evaluated at?

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.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.65P

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