A power-generation prime mover utilizing the steady-flow principle of fluid acceleration, where nozzles are mounted on the moving element. The rotor is turned by the reaction of the issuing fluid jet and is utilized in varying degrees in steam, gas, and hydraulic turbines. All turbines contain nozzles; the distinction between the impulse and reaction principles rests in the fact that impulse turbines use only stationary nozzles, while reaction turbines must incorporate moving nozzles. A nozzle is defined as a fluid dynamic device containing a throat where the fluid pressure drops and potential energy is converted to the kinetic form with consequent acceleration of the fluid. For details of the two basic principles of impulse and reaction as applied to turbine design