I • ENGINEERING CALCULATIONS OF RADIANT HEAT EXCHANGE 

 1.0 



•22 



0.2 0.4 0.6 0.8 1.0 



r/R 



Fig. 1, 2d. View factor for concentric cylinders of equal length. 



the emissive power by the difference of emissive powers of the two 

 surfaces. 



In an enclosure of black surfaces the net heat flux from Si is then 

 given by 



gi.net = {SiFnaTl - S^FncrTt) + (S^FncTt - S,FncrTl) + • • • 

 = SiFMTt - Tl) + SiFn<riTt - Tf) + - ■ ' 

 = SiaTt - (SiFiraTj + S^F^iaTI + S,F,,<tTI + ■ ■ ■) (2-4) 



The above relation permits evaluation of radiation exchange in black 

 systems when the temperatures of all the zones are specified. The more 

 complete analysis, allowing for the equilibrium temperature attained by 



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