﻿Ignition of Gases hy Sudden Compression. 91 



compression. If the volume then remains constant, measure- 

 ment of the rate of fall of pressure with time gives the rate 

 of loss of heat, if the specific heat of the gas is known. One 

 would expect this rate to be closely proportional at any 

 moment to the difference in the average temperature of the 



Ficr. 7. 



£ 400 



£ 300 



.C; 200 



(B.I.) /ffnit/on 

 Max/mum 



Oe/ay=t 

 fa/7 



compre ?s/o/? 

 J? ■ 



/W 



Te/r?p.3/0°C. 

 seconds, 

 speeo'. 



0-5 

 Time in Secor/o's. 



gas and that of the cylinder walls. If the temperature of the 

 gas is T° absolute, and that of the walls is 0, then 



§=<*-">> 



(i) 



where " a " is a constant which we call the cooling factor, 

 and which depends on the nature of the gas, and its degree 

 of turbulence in the cylinder. The results given later will 

 be seen to justify this equation. 

 Integration of (1) gives 



i T o -0 



(2) 



where T is the average temperature when t seconds has 

 elapsed from the moment the average temperature was T . 



