Cyclic process
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A cyclic process is a sequence of changes that returns a system to its initial state. In thermodynamics, a working substance passes through several transformations and finishes with the same pressure, volume, temperature, and internal energy with which it began.
Although the net change in state functions is zero over a complete cycle, heat and work can be exchanged with the surroundings. The area enclosed by a cycle on a pressure–volume diagram represents the net work performed by or on the system.
Heat engines operate through cycles that absorb heat from a high-temperature source, convert part of it into work, and reject the remainder to a lower-temperature sink. Refrigerators and heat pumps run related cycles in the opposite direction by using work to move heat.
Examples include the Carnot, Otto, Diesel, Brayton, Rankine, and refrigeration cycles. Real cycles contain friction, heat loss, turbulence, and other irreversible effects, while ideal cycles provide simplified standards for analysis.
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- Source / publisher: Wikipedia
- URL type: WWW
- Credits: Wikipedia
- URL: https://en.wikipedia.org/wiki/Cyclic_process