1) The spectral, hemispherical absorptivity of an opaque surface and the spectral irradiation at the surface are as shown. %20 1.0 G₂ (W/m².um) 500 0.2 0 0 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 λ(μm) λ(μm) a) How does the spectral, hemispherical reflectivity vary with wavelength? b) What is the total, hemispherical absorptivity of the surface? c) If the surface is initially at 500 K and has a total, hemispherical emissivity of 0.8, how will its temperature change upon exposure to the irradiation?

1) The spectral, hemispherical absorptivity of an opaque surface and the spectral irradiation at the surface are as shown. %20 1.0 G₂ (W/m².um) 500 0.2 0 0 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 λ(μm) λ(μm) a) How does the spectral, hemispherical reflectivity vary with wavelength? b) What is the total, hemispherical absorptivity of the surface? c) If the surface is initially at 500 K and has a total, hemispherical emissivity of 0.8, how will its temperature change upon exposure to the irradiation?

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 11.49P

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