The designation fluid energy machine is a general term for all machines where energy conversion takes place with the help of a fluid.
Steam power plants play a key role in electric power generation. Therefore the Rankine steam power cycle is one of the most important cyclic processes used in industry.
A gas turbine operates according to the open cycle process. Gas turbines are used when high performance and low weight are required.
Compressors are used for compressing and pumping gases. Their higher pressure ratio distinguishes them from fans.