A 4-mm-diameter sphere at 50°C is covered by a 1-mm-thick plastic insulation (k=0.13 W/m°C). The sphere is exposed to a medium at 15 °C, with a combined convective and radiative heat transfer coefficient of 20 W/m2 °C. Determine whether the plastic insulation over the sphere will help or harm heat transfer from the sphere.

A 4-mm-diameter sphere at 50°C is covered by a 1-mm-thick plastic insulation (k=0.13 W/m°C). The sphere is exposed to a medium at 15 °C, with a combined convective and radiative heat transfer coefficient of 20 W/m2 °C. Determine whether the plastic insulation over the sphere will help or harm heat transfer from the sphere.

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.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.33P

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