Impact of rotor design on coaxial rotor performance, wake geometry and noise

Abstract

Extensive research and development is currently underway to design next generation coaxial main rotor systems for heavy lift, high speed and small-scale applications. A variety of platforms are under investigation, including small scale Unmanned Air Vehicles (UAVs), mid-scale concepts like Baldwin Technology's mono-tiltrotor, and full-scale rotorcraft such as Sikorsky Aircraft Corporation's X2 concept. In order to facilitate both the design and evaluation of such new coaxial configurations, it is necessary to develop and validate appropriate analysis tools. This paper describes work performed enhancing the CHARM comprehensive rotorcraft analysis to facilitate its use for aerodynamic/aeroacoustic design of coaxial rotor systems. Correlations of predictions with test data are presented followed by a study of how variations in key rotor design parameters impact coaxial rotor performance, wake geometry and noise. Copyright © 2006 by the American Helicopter Society International, Inc. All rights reserved.