Modeling Helicopter Blade Sailing: Dynamic Formulation and Validation

Abstract

Rotor blade sailing, which is characterized by excessive deflection of rotor blades, can be experienced by shipboard helicopters during rotor start-up and shut-down. In an attempt to model the complete ship-helicopter-rotor system in a way that is geometrically representative and computationally efficient, the system was represented as a discrete-property rigid-body and flexible-element system capable of simulating many important dynamic effects that contribute to the motion of rotor blades. This paper describes the model in detail and discusses validation cases. While both dynamic effects and aerodynamic effects are believed to be important components of blade sailing, this paper focuses exclusively on the dynamics. The validation cases discussed herein suggest that the modeling approach presented offers excellent potential for efficiently modeling blade sailing and other blade motion phenomena.