How does the Brayton cycle describe the operation of a gas-turbine jet engine?

The Brayton cycle describes the thermodynamic process of a gas-turbine engine as an open cycle involving the continuous flow of air. Its operation follows these fundamental stages:12

• Compression: Ambient air is ingested and compressed by a turbocompressor, typically to a pressure ratio of 10 to 40 times the inlet pressure.23
• Combustion: The compressed air enters a combustion chamber where fuel is injected and burned at an essentially constant pressure, significantly raising the temperature of the gas stream.12
• Expansion: The resulting high-pressure, high-temperature combustion gases expand through a turbine. This process extracts energy from the gas to drive the compressor via a torque shaft.123
• Exhaust: In a jet engine, the turbine is designed to provide just enough power to drive the compressor. The remaining high-velocity gases are then ejected through a nozzle to produce thrust.123

Because aircraft design prioritizes minimizing weight and volume, most jet engines operate on this simple, idealized open-cycle version of the Brayton cycle rather than using complex equipment like intercoolers or regenerators.4