| 主权项 |
1. A method for tending to optimize the noise emitted by an auxiliary rotor of a rotorcraft, said rotorcraft extending longitudinally along a first anteroposterior plane (P1) separating a first side from a second side of the rotorcraft, said rotorcraft being provided with at least one main rotor, said rotorcraft being provided with an auxiliary rotor exerting lateral thrust controllable in order to control yaw movement of the rotorcraft, said lateral thrust being directed towards said second side in order to counter torque generated by said main rotor on a fuselage of the rotorcraft, said rotorcraft including a power plant for driving the main rotor and the auxiliary rotor in rotation, said rotorcraft including a tail fin extending in elevation and provided at least in part with a deflectable airfoil of controllable deflection and generating transverse lift, said airfoil presenting a zero deflection angle when said airfoil is present in a second plane (P2), said airfoil having a trailing edge, wherein the deflection angle of said airfoil is controlled to direct its trailing edge towards said second side so that the airfoil presents a deflection angle that is negative relative to the second plane (P2), or to direct its trailing edge towards said first side so that the airfoil presents a deflection angle that is positive relative to the second plane (P2), the airfoil having the function of causing the auxiliary rotor to tend towards at least one predetermined operating point seeking to optimize the performance of the rotorcraft and to minimize the noise generated by the auxiliary rotor, the deflection of said airfoil being controlled at least as a function of a current value of a speed parameter (V) of the rotorcraft and of a current value of a power parameter (W) of said power plant, the method comprising:
controlling the deflection angle of the airfoil to reach a first zone (Z1) for which the deflection angle is at a maximum, reaching a positive threshold angle (δmax), the first zone (Z1) being reached at a low forward speed; controlling the deflection angle of the airfoil to reach a second zone (Z2) for which the deflection angle is at a maximum reaching a positive threshold angle (δmax), the second zone (Z2) being reached at an intermediate forward speed and at high power (W2) developed by the power plant; controlling the deflection angle of the airfoil to reach a third zone (Z3) for which the deflection angle is positioned at a medium deflection, the third zone (Z3) being reached at a high forward speed and at high power (W2) developed by the power plant; and controlling the deflection angle of the airfoil to reach a fourth zone (Z4) for which the deflection angle is small, reaching a negative threshold value (δmin), the fourth zone (Z4) being reached at a high forward speed and at low power (W1) developed by the power plant. |
