F,9 • STATUS OF EXPERIMENTAL KNOWLEDGE 



tions concerned with heat transfer with laminar boundary layers have 

 been attempted, the results of Eber [19] at the Naval Ordnance Labora- 

 tory and Shoulberg, Hill, and Rivas [20] at the Massachusetts Institute of 

 Technology are of particular interest. These experiments were conducted 

 in supersonic wind tunnels, the NOL facility being intermittent and the 

 MIT tunnel continuous. Because of the symmetry of flow, and because 

 the theory for cones is as well developed as for flat plates, Eber used 

 cones for the experimental determination of recovery factors and heat 

 transfer coefiicients. The cones were constructed as follows: (1) thin- 

 walled cones for recovery factor measurement because thin walls immedi- 

 ately assume the insulated-wall temperature, (2) thick-walled cones for 



2 3 4 5 6 



Local Mach number Me 



Fig. F,9a. Comparison of theory and experiment on recovery factor for 

 laminar boundary layers on flat plates and cones in a wind tunnel. 



heat transfer measurement because of their high heat capacity, (3) solid 

 cones for average heat transfer measurement, and (4) subdivided cones 

 for local heat transfer measurement. Inviscid conical flow theory deter- 

 mined conditions just outside the boundary layer. Shoulberg, Hill, and 

 Rivas measured recovery factors by means of a flat plate containing 

 heat-insulated material covered with a sheet of stainless steel. 



Experimental data on recovery factors are plotted in Fig. F,9a, which 

 contains the 0°F, 100°F, and 200°F supply-temperature curves of Fig. 

 F,5s. It is seen that the NOL data, obtained at an average supply tem- 

 perature of 67°F, appears to have some correlation with the theory with 

 respect to Mach number. The MIT data, obtained at an average supply 

 temperature of 110°F, clusters well about the theoretical 100°F supply- 

 temperature curve. 



The data of Eber for local heat transfer coefficients for cones are plotted 



( 369 > 



