z 

 o 



6 



S 



o 

 i 



172 Mr, W. J. Walker on Thermodynamic Cycles 



are known as the variable specific heat "Correction Factors." 

 It is not possible to transform (8) to a simple form such as 

 is obtained in (7) ; baton plotting the graphs shown in fig. 2 



Fie:. 2. 



Cy cle Correc tor? 



VALUES 



'J 



Q 



a — 



3 



to represent the variation of the so-called " correction factor " 

 with a in (7) and with p in (8), it is seen that the two graphs 

 practically coincide up to the value of a or p = 4. The 

 actual figures, assuming r = 8, are:— 



o& or p. 



1-0. 1-1. 



2. 



3. 



4. 



Correction factor in (7) ... 

 „ in (8)... 



•565 -593 

 •565 -590 



•850 

 •880 



113 

 115 



1-41 

 1-39 



From the nature of this practical coincidence between the 

 two graphs, it is evident that the thermal efficiency of the two 

 cycles may be written in the forms: 



Vv = Vv '{l- —(«+!)}, (9) 



V P = Vp 



'{•-¥»♦»} 



(10) 



from which the efficiency^ in the general case, i*e. the Dual 

 Combustion Cycle, may for all practical purposes be written 



( XT 1 



Vm=v>n'\ 1- yC**/ 3 )} (11) 



