초록 ▼

A device for reducing the noise generated by the blades of at least one ring of rotor blades in a turbo-machine by the production of a counter-noise of opposed phase. This is achieved by injection of jets of fluid under pressure through orifices borne by the rotor located near to the periphery of th

A device for reducing the noise generated by the blades of at least one ring of rotor blades in a turbo-machine by the production of a counter-noise of opposed phase. This is achieved by injection of jets of fluid under pressure through orifices borne by the rotor located near to the periphery of the blades, and the flow of the fluid is modulated at a frequency which is a whole number multiple of the rotational frequency of the rotor shaft. Regulation of phase of the modulated injected fluid is carried out in such a manner that the acoustic waves generated by the injected fluid are substantially in opposition, with respect to phase, to those of the noise to be reduced.

대표청구항 ▼

A turbo-machine which comprises: at least one ring of circumferentially spaced, radially oriented rotor blades, the inner edges of which are attached to a rotor shaft; a rotatable cylindrical screen positioned around said rotor blades and integrally connected to their outer edges; and means for redu

A turbo-machine which comprises: at least one ring of circumferentially spaced, radially oriented rotor blades, the inner edges of which are attached to a rotor shaft; a rotatable cylindrical screen positioned around said rotor blades and integrally connected to their outer edges; and means for reducing the noise produced by the rotor blades during rotation with said cylindrical screen, said means comprising means forming a plurality of perforations in said cylindrical screen near the peripheral edges of said rotor blades, means for injecting pressurized fluid in the form of a jet through each of said perforations in said cylindrical screen, means capable of modulating the flow of said fluid jets at a frequency which is a whole number multiple of the rotational frequency of said rotor shaft, means for regulating the phase of said modulated injected fluid such that the acoustic waves generated by said fluid flows are substantially in opposition with respect to phase to those of the noise created by said rotating blades, said means capable of modulating the flow of said fluid jets comprising a stationary pierced ring which is configured to be coaxial with said cylindrical screen and positioned in slidable engagement with the outer periphery thereof, said ring being located between said means forming perforations in said cylindrical screen and said means for injecting pressurized fluid through each perforation such that said fluid must pass therethrough.