F,20 • AERODYNAMIC HEATING OF HIGH SPEED VEHICLES 



G and H located on opposite sides of the nose cone and 12 in. from the tip. 

 The temperatures are plotted up to 61 sec, when the rocket motor 

 burned out. Stations G and H were chosen for study because station H 

 was located aft of a strip of two-dimensional boundary layer trip, whereas 

 station G was not; therefore, the temperature data at those stations 

 should show the difference between the normal boundary layer and a 

 fully turbulent layer. For the purpose of comparing the data with the 

 theory, theoretical temperature curves for laminar and turbulent layers 

 are plotted in the figures. The heat transfer coefficients for the cone were 

 obtained from flat plate theory by use of the rules stated above. During 



1 2 3 



Free stream Mach number Me 



Fig. F,20j. Course of V-2 flight data. 



the period of the measurements, radiation was practically negligible. Also 

 shown in Fig. F,20h is the theoretical time at which the laminar boundary 

 layer becomes completely stable (regardless of Reynolds number) for 

 infinitesimal two-dimensional disturbances due to cooling caused by skin- 

 temperature lag. This limit was obtained by following the course of the 

 wall-to-free-stream temperature ratio in Fig. F,20j and using Fig. F,20k, 

 which is included to show the variation of pertinent properties neces- 

 sary in the heat transfer study for station G. The instant of absolute 

 stabilization seems to correspond to the intersection of the temperature 

 ratio and the stabilization curve in the figure. However, it is suspected 

 that stabilization began before that time, as apparently happened in 

 Fig. F,20h. 



(413 ) 



