Blade-vortex interaction noise controller based on miniature trailing edge effectors

Abstract

The present work focuses on the alleviation of Blade Vortex Interaction (BVI) noise annoyance through a control methodology generating high-frequency aerodynamic BVI counter-actions. The low-power requirements make the Micro-Trailing Edge Effectors (MiTEs) particularly suited for this kind of application. The controller layout is set by observing the BVI scenario while the actuation law is efficiently synthesized through a process based on an analytical unsteady sectional aerodynamic formulation. The validation of the proposed control methodology is carried out through numerical investigations of a realistic helicopter main rotor in flight descent, obtained using computational tools for potential-flow aerodynamic and aeroacoustic analyses based on boundary element method solutions. In order to capture the aerodynamic influence of MiTEs through potential-flow simulations, the MiTEs are replaced by trailing edge plain flaps which provide equivalent aerodynamic responses. Results concerning the proposed controller capability to alleviate high-frequency blade loads and subsequent emitted noise from BVI events are presented and discussed.