Two large parallel plates with surface conditions approximating those of a blackbody are maintained at 816 and 260°C, respectively. Determine the rate of heat transfer by radiation between the plates in W/m2 and the radiative heat transfer coefficient in W/(m2 K).
GIVEN
• Two large parallel plates, approximately black bodies
• Temperatures
? T1 = 816°C = 1089 K
? T2 = 260°C= 533 K FIND
(a) Rate of radiative heat transfer (qr/A) in W/m2 (b) Radiative heat transfer coefficient (hr) in W/(m2 K) ASSUMPTIONS
• Steady state prevails
• Edge effects are negligible
SKETCH
PROPERTIES AND CONSTANTS
Stefan-Boltzmann constant (?) = 5.67 ? 10–8 W/(m2 K)
(a) The rate of heat transfer is given
(b) Let hr represent the radiative heat transfer coefficient
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