Hybrid turbomachine for aircraft with an active acoustic control system

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.

Claims

1. A 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, a plurality of microphones and a plurality of loudspeakers configured to emit noise-attenuating acoustic waves; wherein at least a first microphone of the plurality of microphones is directly connected to the electric generator; wherein at least a first loudspeaker of the plurality of loudspeakers is positioned proximately to the electric generator, and at least a second loudspeaker of the plurality of loudspeakers is positioned proximately to the air inlet of the gas generator and/or at least a third loudspeaker of the plurality of loudspeakers is positioned proximately to the exhaust of the gas generator; wherein the control unit of the acoustic monitoring system is mounted on the electric generator and configured to make an AC-DC electrical conversion of an electromotive force of the electric generator into an adjustable DC voltage intended to be distributed to loads or to energy storage means, wherein the control unit of the acoustic monitoring system further comprises a database including noise models generated as a function of operating parameters of the hybrid turbomachine, and a determination module configured to determine, for each loudspeaker of the plurality of loudspeakers, a respective first signal to be emitted, in response to a failure of one of the plurality of the microphones, based on the noise models to the respective loudspeaker as a function of i) the operating parameters of the hybrid turbomachine and ii) the positioning of the respective loudspeaker; and wherein the acoustic monitoring system attenuates noise generated by the hybrid turbomachine by emitting acoustic waves from the plurality of loudspeakers, wherein the acoustic waves emitted from the plurality of loudspeakers are in phase opposition with acoustic waves received by the plurality of microphones.

2. The hybrid turbomachine according to claim 1, wherein the first microphone of the plurality of microphones is associated with the at least a first loudspeaker, and/or at least a second microphone of the plurality of microphones is positioned proximately to the air inlet of the gas generator and associated with the at least a second loudspeaker, and/or at least a third microphone of the plurality of microphones is positioned proximately to the exhaust of the gas generator and associated with the at least a third loudspeaker, the control unit of the acoustic monitoring system further comprising a monitoring module configured to determine, for each loudspeaker of the plurality of loudspeakers, a respective second signal to be emitted to the respective loudspeaker as a function of the positioning of the respective loudspeaker and of a respective third signal collected by the at least one microphone with which the respective loudspeaker is associated.

3. The hybrid turbomachine according to claim 1, comprising at least one air inlet duct defining the air inlet of the gas generator and at least one exhaust duct defining the exhaust of the gas generator, the at least a second loudspeaker being fixed on a wall of the at least one air inlet duct, and the at least a third loudspeaker being fixed on a wall of the at least one exhaust duct.

4. The hybrid turbomachine according to claim 3, wherein the at least a second microphone is fixed on the wall of the at least one air inlet duct, and the at least a third microphone is fixed on the wall of the at least one exhaust duct.

5. The hybrid turbomachine according to claim 2, wherein the control unit of the acoustic monitoring system comprises analog amplifiers equipped with analog-digital converters for emitting the first signals to the plurality of loudspeakers and collecting the second signals from the plurality of microphones, and digital controllers of a programmable logic array or digital signal processor type for acquiring and processing digital signals.

6. The hybrid turbomachine according to claim 1, comprising a wired communication between the control unit and the plurality of loudspeakers.

7. The hybrid turbomachine according to claim 1, comprising a wireless communication between the control unit and the plurality of loudspeakers.

8. The hybrid turbomachine according to claim 1, wherein the acoustic monitoring system is integrated into a control system of the electric generator.

9. The hybrid turbomachine according to claim 1, wherein the electric generator is a reversible electric machine.

10. An aircraft comprising an Electronic Engine Control Unit of the aircraft and at least one hybrid turbomachine according to claim 1 associated with or integrated into the Electronic Engine Control Unit of the aircraft.

11. The aircraft according to claim 10, wherein the Electronic Engine Control Unit is integrated into a Full Authority Digital Engine Control of the hybrid turbomachine of the aircraft.

12. The aircraft according to claim 10, wherein the control unit is configured to ensure a management of measurements provided by sensors and a command of a system for starting the hybrid turbomachine from a module for managing an on-board network of the aircraft.

13. The aircraft according to claim 10, wherein the control unit is configured to monitor a fuel flow rate supplying the hybrid turbomachine based on a rotational speed of the gas generator or of the electric generator, on a frequency of the electric generator or on a load anticipation for each electric propulsion chain.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic sectional view of a hybrid turbomachine according to one embodiment of the invention.

(2) FIG. 2 is a schematic sectional view of a hybrid turbomachine according to one embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

(3) FIG. 1 schematically represents a sectional view of a hybrid turbomachine 1 according to one embodiment of the invention.

(4) The hybrid turbomachine 1 comprises an electric generator 2, a gas generator 3 and an acoustic monitoring system 4. The electric generator 2 is mechanically connected to the gas generator 3 via a mechanical shaft 5.

(5) The electric generator is a reversible electric machine. It thus allows a bidirectional conversion of the mechanical-electrical energy, that is to say a mechanical-electrical conversion and an electrical-mechanical conversion. The electric generator can generate a three-phase electric current.

(6) The gas generator 3 comprises an air inlet 31, an exhaust 32, at least one compression stage 33, a combustion stage 34 and at least one turbine stage 35 ejecting hot air via the exhaust 32.

(7) The air inlet 31 includes at least one air inlet duct 310 defining the air inlet 31 of the gas generator 3 and an exhaust duct 320 defining the exhaust 32 of the gas generator 3.

(8) In the exemplary embodiment illustrated in FIG. 1, the acoustic monitoring system 4 comprises a control unit 41 mounted on the electric generator 2, two first microphones 42 and four first loudspeakers 43 disposed around the electric generator 2, two second microphones 44 and four second loudspeakers 45 disposed on the air inlet 31 of the gas generator 3, and two third microphones 46 and five third loudspeakers 47 disposed on the exhaust 32 of the gas generator 3. The control unit 41 is electrically coupled to the microphones 42, 44 and 46 and to the loudspeakers 43, 45 and 47 by electric cables making it possible to make a wired connection for the transmission of the signals.

(9) The loudspeakers and the microphones can be of the piezoelectric, electrodynamic or plasma type.

(10) More specifically, the first loudspeakers 43 and the first microphones 42 are fixed on the electric generator 2 or on a casing inside which the electric generator 2 is housed. As shown in FIG. 2, the second microphones 44 and the second loudspeakers 45 are fixed on the air inlet ducts 310 and the third microphones 46 and the third loudspeakers 47 are fixed on the exhaust duct 320.

(11) The control unit 41 of the acoustic monitoring system 4 comprises analog amplifiers equipped with analog-digital converters for emitting processed signals to the loudspeakers 43, 45 and 47 and collecting signals from the microphones 42, 44 and 46, and digital controllers of the programmable logic array or digital signal processor type for acquiring and processing the digital signals.

(12) The control unit 41 of the acoustic monitoring system comprises a monitoring module configured to determine, for each loudspeaker 43, 45 and 47, a signal to be emitted to the loudspeaker as a function of the positioning of the loudspeaker and of the signal collected by the microphone 42, 44 and 46 with which it is associated.

(13) To deal with the possibility of a failure of one of the microphones 42, 44, 46, the control unit 41 of the acoustic monitoring system 4 further comprises a database including simple noise models generated as a function of the operating parameters of the turbomachine 1, and a determination module configured to determine, for each loudspeaker 43, 45 and 47, a signal to be emitted to the loudspeaker as a function of the operating parameters of the turbomachine 1 and as a function of the positioning of the loudspeaker.

(14) The acoustic monitoring system 4 thus allows actively attenuating the noise generated by the hybrid turbomachine 1 and perceived on the ground and in the cabin. The sound waves emitted by the loudspeakers 43, 45 and 47 of the system 4 generate acoustic waves in phase opposition with the waves picked up by the microphones 42, 44 and 46 to generate destructive interference with the waves generated by the turbomachine 1.

(15) The turbomachine 1 is intended to be mounted on an aircraft comprising an Electronic Engine Control Unit of the aircraft also known under the acronym EECU. The turbomachine 1 is either associated with or integrated into the Electronic Engine Control Unit of the aircraft. The Electronic Engine Control Unit is preferably integrated into a Full Authority Digital Engine Control of the turbomachines of the aircraft also known under the acronym FADEC.

(16) Furthermore, the control unit 41 of the turbomachine 1 is configured to ensure the management of measurements provided by sensors and a command of a starting system from a module for managing the on-board network of the aircraft.

(17) The control unit 41 is configured to monitor a fuel flow rate supplying the turbomachine 1 based on a rotational speed of the gas generator 3 or of the electric generator 2, on the frequency of the electric generator 2 or on a load anticipation for each electric propulsion chain.