A propelling nozzle is the component of a jet engine that operates to constrict the flow, to form an exhaust jet and to maximise the velocity of propelling gases from the engine.
Propelling nozzles can be subsonic, sonic, or supersonic. Physically the nozzles can be convergent, or convergent-divergent. Convergent-divergent nozzles can give supersonic jet velocity within the divergent section, whereas in a convergent nozzle the exhaust fluid cannot exceed the speed of sound within the nozzle.
Propelling nozzles can be fixed geometry, or they can have variable geometry, to give different throat and exit diameters so as to deal with differences in ambient pressure, flow and engine pressure; thus permitting improvement of thrust and efficiency.
Read more about Propelling Nozzle: Principles of Operation, Convergent Nozzles, Divergent Nozzle, Convergent-divergent Nozzles, Afterburners
Famous quotes containing the word propelling:
“Compare society to a boat. Her progress through the water will not depend upon the exertion of her crew, but upon the exertion devoted to propelling her. This will be lessened by any expenditure of force in fighting among themselves, or in pulling in different directions.”
—Henry George (1839–1897)