Chapter 12 Radiation Heat Transfer12-29 The base and the dome of a hemispherical furnace are maintained at uniform temperatures. The net rate of radiation heat transfer from the dome to the base surface is to be determined. Assumptions1Steady operating conditions exist 2The surfaces are opaque, diffuse, and gray. 3Convection heat transfer is not considered.AnalysisThe view factor is first determined from FFFF11111212011=+=→=(flat surface)(summation rule)Noting that the dome is black, net rate of radiation heat transfer from dome to the base surface can be determined from kW759.4=×=−⋅×−=−−=−=−W10594.7])K1000()K400)[(KW/m1067.5)(1](/4)m5()[7.0()(544428242411211221πσεTTFAQQ&&T1= 400 K ε1= 0.7 T2= 1000 K ε2= 1 D= 5 m The positive sign indicates that the net heat transfer is from the dome to the base surface, as expected. 12-30 Two very long concentric cylinders are maintained at uniform temperatures. The net rate of
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This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.