What is the Brayton Cycle?

What is the Brayton Cycle?

• A. The working cycle of a gas turbine engine
• B. The cycle for reciprocating engines
• C. The cycle for diesel engines
• D. The cycle describing rocket propulsion

Answer: (A)

The Brayton Cycle is the thermodynamic path used by a gas turbine engine to convert fuel energy into shaft work. In this cycle, air is first compressed, then heated at essentially constant pressure by burning fuel in a combustor, and finally expanded through a turbine to produce work before being exhausted back to the atmosphere. In an ideal Brayton cycle, the compression and expansion are isentropic (no entropy change), and the heat addition and rejection occur at constant pressure. Real engines follow a similar sequence but with irreversibilities and pressure losses. This cycle is characteristic of open-flow gas turbines: air continuously enters the engine, goes through the compressor, combustor, and turbine, and leaves as exhaust. It’s the standard model for how aircraft jet engines and many power-generation gas turbines operate. Other engine cycles describe different types of engines—for example, reciprocating engines use cycles like Otto or Diesel, which involve pistons and different ways of heat addition, and rocket propulsion relies on entirely different flow paths and energy-release mechanisms.

The Brayton Cycle is the thermodynamic path used by a gas turbine engine to convert fuel energy into shaft work. In this cycle, air is first compressed, then heated at essentially constant pressure by burning fuel in a combustor, and finally expanded through a turbine to produce work before being exhausted back to the atmosphere. In an ideal Brayton cycle, the compression and expansion are isentropic (no entropy change), and the heat addition and rejection occur at constant pressure. Real engines follow a similar sequence but with irreversibilities and pressure losses.

This cycle is characteristic of open-flow gas turbines: air continuously enters the engine, goes through the compressor, combustor, and turbine, and leaves as exhaust. It’s the standard model for how aircraft jet engines and many power-generation gas turbines operate. Other engine cycles describe different types of engines—for example, reciprocating engines use cycles like Otto or Diesel, which involve pistons and different ways of heat addition, and rocket propulsion relies on entirely different flow paths and energy-release mechanisms.