Two parallel concentric disks, 20 cm and 40 cm indiameter, are separated by a distance of 10 cm. The smallerdisk (« = 0.80) is at a temperature of 300°C. The larger disk(« = 0.60) is at a temperature of 800°C.(a) Calculate the radiation view factors.(b) Determine the rate of radiation heat exchange betweenthe two disks.(c) Suppose that the space between the two disks is completelysurrounded by a reflective surface. Estimatethe rate of radiation heat exchange between the twodisks.

Two parallel concentric disks, 20 cm and 40 cm indiameter, are separated by a distance of 10 cm. The smallerdisk (« = 0.80) is at a temperature of 300°C. The larger disk(« = 0.60) is at a temperature of 800°C.(a) Calculate the radiation view factors.(b) Determine the rate of radiation heat exchange betweenthe two disks.(c) Suppose that the space between the two disks is completelysurrounded by a reflective surface. Estimatethe rate of radiation heat exchange between the twodisks.

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 11.23P

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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.

Question

Two parallel concentric disks, 20 cm and 40 cm in
diameter, are separated by a distance of 10 cm. The smaller
disk (« = 0.80) is at a temperature of 300°C. The larger disk
(« = 0.60) is at a temperature of 800°C.
(a) Calculate the radiation view factors.
(b) Determine the rate of radiation heat exchange between
the two disks.
(c) Suppose that the space between the two disks is completely
surrounded by a reflective surface. Estimate
the rate of radiation heat exchange between the two
disks.

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