F,20 • AERODYNAMIC HEATING OF HIGH SPEED VEHICLES 



tour 580°R represents the case where the radiation just balances the 

 absorption of heat from the sun. This temperature (580°R) is then the 

 temperature of a body at rest in the atmosphere or in motion out in 

 space. It may also be the temperature of a body in motion in the atmos- 

 phere when the speed is such that the boundary layer temperature is 

 580°Il. The fact that there are lower temperature contours within the 



1000 



900 



o 



4— 



o 



o 

 a 



E 



800 



700 



CO 



600 



500 



10 20 30 40 50 60 



Time, seconds after take-off 



70 



Fig. F,20h. Correlation of theory with skin-temperature data from a V-2 

 rocket. Boundary layer not tripped. Data of Fischer and Norris. 



580°E, contour means that as a body starts from rest the temperature 

 falls at first, because the ambient air is at a lower temperature than the 

 body temperature, and then rises as the friction within the boundary 

 layer increases. At a certain speed, the boundary layer temperature be- 

 comes equal to the wall temperature, whereupon the wall radiates heat 

 at exactly that rate at which it receives it from space. At higher speeds, 

 the friction increases the boundary layer temperature and heat is trans- 



(411 ) 



