Unformatted text preview: Chapter 12 Radiation Heat Transfer Radiation Heat Transfer Between Surfaces 1219C The analysis of radiation exchange between black surfaces is relatively easy because of the absence of reflection. The rate of radiation heat transfer between two surfaces in this case is expressed as where A ) ( 4 2 4 1 12 1 T T F A Q − σ = & 1 is the surface area, F 12 is the view factor, and T 1 and T 2 are the temperatures of two surfaces. 1220C Radiosity is the total radiation energy leaving a surface per unit time and per unit area. Radiosity includes the emitted radiation energy as well as reflected energy. Radiosity and emitted energy are equal for blackbodies since a blackbody does not reflect any radiation. 1221C Radiation surface resistance is given as R A i i i i = − 1 ε ε and it represents the resistance of a surface to the emission of radiation. It is zero for black surfaces. The space resistance is the radiation resistance between two surfaces and is expressed as R A i i i i = −...
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 Fall '10
 Dr.DanielArenas
 Thermodynamics, Mass, Heat, Radiation, Heat Transfer, Ri

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