carnot's cycle

from the GNU version of the Collaborative International Dictionary of English.

• (Thermodynamics) An ideal heat-engine cycle in which the working fluid goes through the following four successive operations: (1) Isothermal expansion to a desired point; (2) adiabatic expansion to a desired point; (3) isothermal compression to such a point that (4) adiabatic compression brings it back to its initial state.