A,26 • EFFECT OF HEAT TRANSFER ON TRANSITION 



narrow ranges of the variables. Data are included on a flat plate, cone 

 cylinder, paraboloid cylinder, and the RM-IO body of revolution. The 

 Mach numbers represented are 1.61, 2.40, 2.87, and 3.12. 



The curves of Fig. A, 26b suggest that three of the curves are approach- 

 ing vertical asymptotes at sufficiently small values of {T^ — T,)/Tl. The 

 Reynolds numbers attainable are always limited by model size and tunnel 

 characteristics so that complete stabilization to infinite Reynolds number 

 can never be demonstrated. The asymptote values are compared with the 



Fig. A,26b. Effect of heating and cooling on transition 

 Reynolds number at supersonic speed. 



Dunn and Lin theoretical curve in Fig. A,26c. The experimental values 

 are of the same order of magnitude as those predicted by theory. 



There are a number of individual papers giving additional data on the 

 effects of heat transfer on transition at supersonic speeds. Higgins and 

 Pappas [117] found that heating a flat plate to a wall temperature 200°F 

 above the recovery temperature reduced the transition Reynolds number 

 from 1.25 milHon to 600,000 in the NACA Ames 6-inch heat transfer 

 wind tunnel at a Mach number of 2.4. Scherrer [118] studied the effect of 

 heating and cooling on transition on a 20° cone in the Ames 1 X 3-foot 

 wind tunnel No. 1 at Mach numbers of 1.5 and 2.0. In the absence of 

 heating, the transition Reynolds number was 4.1 million. Heating to a 



< 65) 



