Project MANOEUVRES - Towards Real-Time Noise Monitoring and Enhanced Rotorcraft Handling Based on Rotor State Measurements

The MANOEUVRES project represents an effort aimed at providing innovative solutions for noise abatement in rotorcraft terminal manoeuvres, when the vehicle approaches the ground and the acoustic impact is higher. This is achieved by in-flight monitoring of the emitted noise, enabled by a new cockpit instrumentation, the Pilot Acoustic Indicator (PAI), and by an innovative contactless rotor state measurement system capable of acquiring the blade attitude angles. The PAI displays a condensed acoustic impact information retrieved through a real-time estimation of the actual noise emitted and radiated. Noise strongly depends on the actual helicopter dynamics, and especially on the main rotor loading and orientation. The latter can be estimated by means of the rotor state measurement system and fed to the PAI, which incorporates a pre-calculated acoustic database, to yield a quasi-steady approximation of the full acoustic spatial emission. The paper reports on the project current state, involving studies in unsteady aeroacoustic prediction, rotor state measurement system design and development, PAI design and development, as well as the formulation of innovative flight control laws enabled by the availability of blade angle measurements, which aim at higher coupled vehicle/pilot performance and handling qualities.