648 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



A glance at the working chart for this type shows that the whole type 

 B plaue has, as it were, shrunk horizontally toward its high efficiency 

 fuel line. That Hue has many of the same interesting properties on the 

 type C plane that it had before, in that here also it is the locus of the 

 same set of first order cycles, and is, for the engineer, a natural bound- 

 ary. It is interesting to notice that any line of any family of curves 

 whatever crosses this high efficiency fuel line at exactly the same point 



50 



100 



ISO 



350 



400 



450 500 



Q in BTU 



200 250 300 



Figure 14. 

 Tijpe, C. Final temperature. These curves are for cycles with isotliermal com- 

 pression and a subsequent transfer of heat from the exhaust. Tliey all start from 

 the point Q = 0, P = 1, and there are an infinite number of them in the lower part 

 of the plane. (Cf. Figures 3 and 8.) 



in both the type B and the type C planes, although the general char- 

 acter of the line may be totally altered. 



As has already been suggested, the dependence of the properties of 

 these cycles upon the values of the parameters jo^ and T^ is very simple. 

 In no case is p^ involved at all. The efficiency and work of a Brayton 

 cycle and the final temperature and velocity of a regenerative cycle are 

 independent of T, also, and the curves of Figures 6, 7, 14, and 15 may be 

 used whatever the initial conditions. In the isothermal case, the T^ and 



