Analysis of Helicopter Rotor Nonlinear Dynamics by Numerical Continuation Method

The capability of numerical continuation to trace branches of periodic solutions is exploited in order to investigate the behavior of an articulated rotor blade as design and flight parameters are varied. The aim of the paper is to demonstrate the use of Dynamical System Theory and bifurcation analysis as an innovative tool for supporting rotor design, an approach based on the determination of critical thresholds for motion variables and rotor design parameters that determine unstable or simply undesirable behaviors of the coupled, flap-lag motions. In spite of the relative simplicity of the model presently implemented, the potential of the method is fully demonstrated. The reported results show a reasonable trend in the evolution of blade motion as different parameters are varied with continuity.