Depiction of the basic heat cycle: an expansion phase, left, in which a working body put in contact with hot body, followed by a contraction phase, right, where the working body put in contact with cold body.
In thermodynamics, a heat cycle consists of an expansion phase, in which a working body expands in volume, and a contraction phase, in which the working body contracts in volume.
Overview The concept of the heat "cycle" was first enunciated in 1824 by French physicist Sadi Carnot in what is called the Carnot cycle, a detailed step-by-step described heat cycle.
