Chapter 12 Radiation Heat Transfer12-24ETop and side surfaces of a cubical furnace are black, and are maintained at uniform temperatures. Net radiation heat transfer rate to the base from the top and side surfaces are to be determined. Assumptions1Steady operating conditions exist 2The surfaces are opaque, diffuse, and gray. 3Convection heat transfer is not considered.PropertiesThe emissivities are given to be ε= 0.7 for the bottom surface and 1 for other surfaces. AnalysisWe consider the base surface to be surface 1, the top surface to be surface 2 and the side surfaces to be surface 3. The cubical furnace can be considered to be three-surface enclosure with a radiation network shown in the figure. The areas and blackbody emissive powers of surfaces are 2232221ft400)ft10(4ft100)ft10(=====AAA244284332442842224428411Btu/h.ft866,56)R2400)(R.Btu/h.ft101714.0(Btu/h.ft233,11)R1600)(R.Btu/h.ft101714.0(Btu/h.ft702)R800)(R.Btu/h.ft101714.0(=×=σ==×=σ==×=σ=−−−TETETEbbb
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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.