Abstract: Hybrid turbomachine comprising an electric generator, a gas generator equipped with an air inlet and with an exhaust and an acoustic monitoring system comprising a control unit and a plurality of loudspeakers. At least a first loudspeaker is disposed on the electric generator, and/or at least a second loudspeaker is disposed on the air inlet of the gas generator, and/or at least a third loudspeaker is disposed on the exhaust of the gas generator. The control unit of the acoustic monitoring system is mounted on the electric generator and is configured to make an AC-DC electrical conversion of the electromotive force of the electric generator into an adjustable DC voltage intended to be distributed to loads or to energy storage means.

Abstract: A noise-attenuating covering configured for example for a pipe for guiding gases along a gas path. The covering includes a wall defining the gas path and at least one resonance cavity, the wall being pierced with holes for fluid communication between the gas path and the resonance cavity to attenuate noise. The holes have substantially identical diameters and, since the pipe is arranged to guide the gases in the downstream direction, a number of the openings per wall surface unit decreases continuously along the gas path in the downstream direction, such as to confer on the wall substantially constant acoustic resistance along the gas path, for which the noise attenuation is optimized along the gas path.

Abstract: A noise-attenuating covering configured for example for a pipe for guiding gases along a gas path. The covering includes a wall defining the gas path and at least one resonance cavity, the wall being pierced with holes for fluid communication between the gas path and the resonance cavity to attenuate noise. The holes have substantially identical diameters and, since the pipe is arranged to guide the gases in the downstream direction, a number of the openings per wall surface unit decreases continuously along the gas path in the downstream direction, such as to confer on the wall substantially constant acoustic resistance along the gas path, for which the noise attenuation is optimized along the gas path.

Abstract: A device for ejecting gas from a gas turbine engine, which includes: an outer wall and an inner wall defining a gas flow path therebetween, the inner wall forming a central body defining an inner cavity, the outer wall being perforated and communicating with at least one outer resonance cavity for attenuating noise in a first range of sound frequencies; and a mechanism for placing the outer and inner cavities in fluid communication, extending through the gas flow path, the inner cavity thus forming a resonance cavity for attenuating the noise in a second range of sound frequencies. The device can, for example, be used to attenuate two ranges of sound frequencies.

Abstract: A gas turbine engine, in which gases flow upstream to downstream, including a combustion chamber, a high-pressure turbine placed downstream from the combustion chamber, arranged so as to receive combustion gases from the combustion chamber, a free turbine, and an exhaust-gas guide cone attached to the free turbine downstream from the free turbine, the turbine engine emitting sound waves during operation. The guide cone includes a sound suppressor, for example with a Helmholtz resonator structure, with a resonant cavity and a resonator neck in communication with an opening, arranged so as to suppress the sound waves emitted by the turbine engine.

Abstract: A device for attenuating acoustical noise from an exhaust nozzle of a turbojet is disclosed. The turbojet exhaust nozzle includes a central body defining the inner surface of the primary gas flow path. The central body includes an outer wall defining one, and only one, resonator cavity. The single resonator cavity is in fluid communication with the primary gas flow path via orifices through at least one upstream portion of the outer wall. The single resonator cavity and plurality of orifices compose a Helmholtz resonator.

Abstract: The invention relates to a central body of a turbojet nozzle comprising a wall forming a cavity. The central body comprises a plurality of orifices pierced over at least one upstream portion of its wall and a single resonance cavity forming a Helmholtz resonator. Such a central body makes it possible to attenuate the low frequency noises.

Abstract: A process for attenuating noise generated in a turbomachine by the interaction of rotor blades with stator vanes downstream of the rotor blades comprises the injection of a fluid in continuous jets upstream of the blades through a number of orifices equal to the number of vanes. The orifices are arranged in a ring and are capable of pivoting about the rotor axis by an angle at least equal to the angular pitch between two consecutive vanes. The angular position is controlled so that the sound waves produced by the interaction between the jets and the blades are of opposite phase to those produced by the interaction of the blades with the vanes.

Abstract: A process for attenuating noise generated in a turbomachine by the interaction of rotor blades with stator vanes downstream of the rotor blades comprises the injection of a fluid in continuous jets upstream of the blades through a number of orifices equal to the number of vanes. The orifices are arranged in a ring and are capable of pivoting about the rotor axis by an angle at least equal to the angular pitch between two consecutive vanes. The angular position is controlled so that the sound waves produced by the interaction between the jets and the blades are of opposite phase to those produced by the interaction of the blades with the vanes.