30 



HANDBOOK OF MECHANICAL DESIGN 



MEAN COOLING TEMPERATURE 



Where V/\ and Yg are any fwo ordinafes fo 

 the curve Y=ae''"' the usual form of cooling 

 curve, the mean value Ym ofallfheordinafes 

 between V^ and Yg Is given by the relation 



Log mean Ym = 



Ya-Yb 



Log Ya- Log Yg 



Ttie dotted line stiows ttiat for a body cooling 

 tram ISOdeg.rto 70deg. F: in air at dodeg.F., 

 ttie mean temperature difference Is 36.3 deg. t 

 the mean temperature ttierefore Is 96.5 degF. 



40 50 60 



Mean Ordinate Y^ 



