Brayton cycle

(redirected from Brayton/Joule cycle)

Brayton cycle

[′brāt·ən ‚sī·kəl]
(thermodynamics)
A thermodynamic cycle consisting of two constant-pressure processes interspersed with two constant-entropy processes. Also known as complete-expansion diesel cycle; Joule cycle.

Brayton cycle

A thermodynamic cycle (also variously called the Joule or complete expansion diesel cycle) consisting of two constant-pressure (isobaric) processes interspersed with two reversible adiabatic (isentropic) processes.

The thermal efficiency for a given gas, air, is solely a function of the ratio of compression. This is also the case with the Otto cycle. For the diesel cycle with incomplete expansion, the thermal efficiency is lower.

The Brayton cycle, with its high inherent thermal efficiency, requires the maximum volume of gas flow for a given power output. The Otto and diesel cycles require much lower gas flow rates, but have the disadvantage of higher peak pressures and temperatures. These conflicting elements led to many designs, all attempting to achieve practical compromises. With the development of fluid acceleration devices for the compression and expansion of gases, the Brayton cycle found mechanisms which could economically handle the large volumes of working fluid. This is perfected in the gas turbine power plant. See Gas turbine, Thermodynamic cycle

Brayton cycle

A name given to the thermodynamic cycle of a gas turbine engine to provide thrust. This is varying the volume constant pressure cycle of events and is commonly called the constant pressure cycle. Also called a continuous combustion cycle because of four constant and continuous events (i.e., intake, compression, expansion including power, and exhaust). It is named after George B. Brayton—an American engineer. Also called a Joule cycle. (See page 121)