Hello,

A reversible process in thermodynamics is one in which the direction of the process may be reversed to return the system to its initial state by generating tiny changes to some feature of the system's surroundings. The system is in thermodynamic equilibrium with its surroundings during the whole reversible process.Due to the slowness of reversible processes, the system is constantly extremely close to equilibrium.

Uniform and gradual expansion or compression of a fluid, such as fluid flows in a well-designed turbine, compressor, nozzle, or diffuser, are examples of reversible processes. With no (noticeable) internal temperature, pressure, or velocity changes, reversible processes are differently removed from equilibrium.

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