What thermodynamic cycle does a gas turbine engine operate on?

A gas turbine engine operates on the Brayton cycle. This cycle is specifically designed for gas turbine engines and is characterized by its use of constant pressure for the combustion process.

In the Brayton cycle, air is drawn into the engine and compressed, leading to an increase in temperature and pressure. The compressed air then enters the combustion chamber, where fuel is burned at nearly constant pressure, further increasing the temperature. The high-temperature, high-pressure gas then expands through the turbine, producing work and generating thrust. The key aspect of the Brayton cycle is that it efficiently converts thermal energy into mechanical energy, which is essential for the operation of gas turbine engines used in aviation and power generation.

In contrast, the Otto and Diesel cycles are used in reciprocating engines where combustion occurs at constant volume (Otto) or at variable volume with a compression ratio (Diesel). The Rankine cycle primarily pertains to steam engines and is not applicable to gas turbine engines, as it involves phase changes from liquid to vapor and vice versa, which is not a process seen in gas turbines.