Radiation heat transfer gray-body

In this chapter v.e have examined several means for analyzing radiation heat transfer. The gray-body assumption, although not strictly correct, is a viable method for performing heat-transfer calculations. Assumptions of uniform ra-diosity and irradiation over surfaces are also not strictly correct but provide an approximation which is usually well within the accuracy of knowledge of surface proper , e. (n Table 8-6, we present a tabular summary of a few formulas which are ofte . used. 

If neither body is a perfect radiator (both gray), then the net radiation heat transfer between the two bodies will be ... 

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