The
Brayton cycle is a
thermodynamic cycle that describes the workings of a constant pressure heat engine.
Gas turbine engines and
airbreathing jet engines use the Brayton cycle. Although the Brayton cycle is usually run as an
open system (and indeed
must be run as such if internal combustion is used), it is conventionally assumed for the purposes of
thermodynamic analysis that the exhaust gases are reused in the intake, enabling analysis as a closed system.