Advanced Thermodynamics for Engineers, 2nd Edition

ENGINE CYCLES AND THEIR

EFFICIENCIES

3

The concept of internally reversible cycles was introduced in Section 2.7: these are sometimes known

as endoreversible cycles. The advantage of considering endoreversible cycles is that the area of the

cycle on a T–s diagram represe nts the work done by, or on, the fluid when it executes that cycle. If a

cycle is not endoreversible then the area on the T–s diagram of the cycle is not equivalent to the work

done. There are a number of important endoreversible cycles and these are introduced below.

3.1 HEAT ENGINES

3.1.1 CARNOT CYCLE

The Carnot cycle, as originally proposed, is both internally and externally reversible. ...