F,ll • HEAT TRANSFER 



analogy factor is [22] 

 s = >S(1) = 



Pr^ • exp I - / (1 - Pr) - 



\ 7t(0) t 



] du^ 



(11-18) 



in which Pr varies across the boundary layer. 



An algebraic formula can be derived for s if the same assumptions 

 concerning velocity and shear distribution are stipulated as in the de- 



0.89 



0.88 



0.87 



0.86 



Tins 0.85 



0.84 



0.83 



0.82 



0.81 



2 3 



Fig. F,lld. Recovery factor for a turbulent boundary layer on a flat plate in 

 free flight in air as a function of Mach number. Te = 400°R. 



velopment of the recovery factor r. The derivation is considerably simpler 

 than for r and leads to 



s = 



.) 



< 379 ) 



+ 



(U-19) 



