Aeroacousto-Elastic Modeling for Response Analysis of Helicopter Rotors

Abstract

Vibratory loads and noise emission are by-products of the steady flight of helicopter rotors. The fuselage vibrations caused by the vibratory loads from the main rotor affect helicopter ride comfort and have a negative impact both on the fatigue-life of the structure and on functionality of onboard instruments. Furthermore, it is a common experience that the flight of helicopters may be clearly perceived by the hearing of the corresponding sound field generated. In particular flight conditions, the acoustic annoyance from the main rotor may become severe, and this affects the environmental and public acceptance of helicopters. Therefore, the design of a new-generation helicopter has to include the limitation of vibratory loads and noise emission among its goals, and in this context the availability of reliable simulation tools for their prediction is of primary importance. In this chapter, the formulation developed at the Department of Mechanical and Industrial Engineering of University Roma Tre for the derivation of an aeroacousto-elastic simulation tool for helicopter rotors is described, highlighting the important role played by the unsteady aerodynamic model in such a kind of solvers.