A plot of Eq. (18) is shown in Fig. 8 for * = * =0.9,
compared with the ideal efficiency. As seen, when losses are
taken into account, there will be a maximum cycle efficiency
for any fixed temperature ratio which is lower than the
pressure ratio,* , for a maximum cycle efficiency can be
obtained when the derivative of Eq. (18) is taken, and set equal
respectively, it is concluded that for the optimum pressure ratio
corresponding Carnot efficiency. The so-called optimum
numerical methods are needed to solve for . Comparing the values of *** and *** from figs, 6 and 8,
respectively, it is concluded that for the optimum pressure ratio based on work occurs at a lower pressure ratio than the point of maximum efficiency at the same temperature ratio, i.e.