For approximate calculations, the sun may be considered a black body, emitting radiation with maximum intensity at 1 = 0.5 microns (5000 Â). On this basis, estimate (a) the surface temperature of the sun and (b) the emitted heat flux at the surface of the sun. Solution. a. From Wien's displacement law, 0.2884 (0.2884 cm ° K) T = Amax = 5760° K = 10,400° R (0.5 x 104 cm) b. From the Stefan-Boltzmann law, - (0.1712 x 10-8)(10,400)ª = 2.0 x 10' Btu hr" ft-2

For approximate calculations, the sun may be considered a black body, emitting radiation with maximum intensity at 1 = 0.5 microns (5000 Â). On this basis, estimate (a) the surface temperature of the sun and (b) the emitted heat flux at the surface of the sun. Solution. a. From Wien's displacement law, 0.2884 (0.2884 cm ° K) T = Amax = 5760° K = 10,400° R (0.5 x 104 cm) b. From the Stefan-Boltzmann law, - (0.1712 x 10-8)(10,400)ª = 2.0 x 10' Btu hr" ft-2

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 11.66P

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Two large parallel plates with surface conditions approximating those of a blackbody are maintained at 816C and 260C, respectively. Determine the rate of heat transfer by radiation between the plates in W/m2 and the radiative heat transfer coefficient in W/m2K.
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