F,16 • STATUS OF EXPERIMENTAL KNOWLEDGE 

 tunnel. For example, when the Mach number is zero, Eq. 16-1 becomes 



0.242 2 / /Tw\ 



c){T^/T.)^ B^^^ + ^ - 1) = 0-41 + log {Re-ci) - {p + n) log (^- j 



(16-3) 



in which p = ^ for Z = Ky and p = f or Z = —K{du/dy)/{d}u/dy'^), but 

 may be adjusted by the data. Experimental data under these conditions 

 are apparently not available as yet. 



Heat transfer. The necessary ingredients, viz. r, s, and C/, have now 

 been presented for the calculation of heat transfer g^ from Eq. 11-1. 





Fig. F,16b. Effect of heat transfer and Mach number on mean skin friction 

 coefficient according to Eq. 16-2 for a Reynolds number of 10'. 



They have also been checked against experiment. Therefore, it is ex- 

 pected that the resulting heat transfer calculations will be adequate for 

 engineering purposes. 



A final check on the theory may be made by measuring the heat trans- 

 fer rate into or out of the boundary layer, thus obtaining the value of 

 St directly. In Fig. F,16c, F,16d, and F,16e are plotted some heat transfer 

 coefficients obtained by Shoulberg and others [Ji.5] at the Massachusetts 

 Institute of Technology for M, = 2.0 at T^/T, = 2.1, ilfe = 2.5 at 

 Tw/T^e = 2.7, and M^ = 3.0 at T^/T^ = 3.3. Theoretical curves, derived 

 from Eq. 11-2, 11-19 (corrected for Mach number and heat transfer effect, 

 say s = 0.825) and 11-29, are also drawn in the figures. Good agreement 



< 393 ) 



