Answered: A directionally emitting surface has an…

A directionally emitting surface has an emissivity of 0.7 for angles up to 45° from vertical and 0.2 for the rest of the range. Determine the total emissivity of the surface.

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 11.41P: 11.41 Determine the steady-state temperatures of two radiation shields placed in the evacuated space...

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Concept explainers

Radiation

Radiation can be described as the energy in the form of a particular matter or electromagnetic waves traveling in the air and can be in the form of light, sound, and heat. Radiation can be detected through special instruments like X-rays. The radiation from a cooler object is less intense as compared to the radiation from hot objects.

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A directionally emitting surface has an emissivity of 0.7 for angles up to 45° from vertical and 0.2 for the rest of the range. Determine the total emissivity of the surface.

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