12. A piece of copper wire is initially at 150 C. We now expose this wire to air at 38 C. Find a) the rate of heat transfer at the moment of exposure and b) compare this rate of heat transfer to the rate of heat transfer from thermal radiation at the moment of exposure. Data: For copper at 150 C; k = 374 W/m-K, c = 381 J/kg-K, p = 8938 kg/m², ɛ = 0.8. The heat transfer coefficient is h = 5 W/m².-K. [Ans.: Initial heat loss is 64% due to radiation and 36% due to convection].

12. A piece of copper wire is initially at 150 C. We now expose this wire to air at 38 C. Find a) the rate of heat transfer at the moment of exposure and b) compare this rate of heat transfer to the rate of heat transfer from thermal radiation at the moment of exposure. Data: For copper at 150 C; k = 374 W/m-K, c = 381 J/kg-K, p = 8938 kg/m², ɛ = 0.8. The heat transfer coefficient is h = 5 W/m².-K. [Ans.: Initial heat loss is 64% due to radiation and 36% due to convection].

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 1.77P: 1.77 Explain each in your own words. (a) What is the mode of heat transfer through a large steel...

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