US 11,939,072 B2
Method of optimizing the noise generated on the ground by a rotorcraft
Nayibe Gomez, Aix en Provence (FR)
Assigned to AIRBUS HELICOPTERS, Marignane (FR)
Filed by AIRBUS HELICOPTERS, Marignane (FR)
Filed on Feb. 5, 2020, as Appl. No. 16/782,246.
Claims priority of application No. 1901399 (FR), filed on Feb. 12, 2019.
Prior Publication US 2020/0331621 A1, Oct. 22, 2020
Int. Cl. B64D 31/06 (2006.01); B64D 27/02 (2006.01); B64F 5/60 (2017.01)
CPC B64D 31/06 (2013.01) [B64F 5/60 (2017.01); B64D 27/026 (2024.01)] 18 Claims
OG exemplary drawing
 
1. A method of optimizing the noise generated by a rotorcraft on the ground, the rotorcraft including a hybrid power plant provided with at least one engine and with at least one electric machine, at least one rotor driven in rotation with mechanical power from the hybrid power plant, and at least one electrical energy source electrically powering the at least one electric machine via an electrical network, the method comprising:
a first monitoring step with a detection device for monitoring whether the rotorcraft is on the ground;
a second monitoring step with a control unit for monitoring whether the at least one engine is in the started or on state or in the stopped or off state, and for monitoring a speed of the at least one engine;
a third monitoring step with a control device for monitoring whether the at least one electric machine is in the on state or in the off state, and for monitoring a speed of the at least one electric machine;
detecting by the control unit from the second monitoring step that a first engine of the at least one engine is in the on state;
a first control step with the control unit for controlling the first engine, in response to the rotorcraft being on the ground, so as to lower the speed of the first engine until the speed of the first engine reaches a predetermined speed referred to as a silent speed, the silent speed being either an idling speed of the first engine or a reduced speed of the first engine making it possible to reduce the noise generated by the first engine, the reduced speed being a speed of the first engine that keeps the first engine in the on state; and
in response to the speed of the first engine being lowered to reach the silent speed, a second control step with the control device for controlling the at least one electric machine so that the at least one electric machine delivers a supplementary mechanical power in addition to mechanical power delivered by the first engine for driving the at least one rotor in rotation while complying with a setpoint speed of rotation of the at least one rotor.