In-Plane Vortex-Rotor Interaction and its Implication on Rotor Trim: an Analytic Solution for Arbitrary Vortex Orientation and Position

Abstract

The general aerodynamic problem of arbitrary oriented in-plane vortex-rotor interaction was investigated in the past only by numerical simulation. Just one special case of in-plane vortex-rotor interaction with the vor-tex axis in flight direction was recently solved analytically. In this paper the analytical solution for arbitrary in-plane vortex orientation and position relative to the rotor on thrust and hub moments is given that was pub-lished for the first time just before. Results provide the vortex impact on rotor trim (thrust, aerodynamic roll-ing and pitching moments about the hub) and the rotor controls required to mitigate these disturbances. In this paper the sensitivity of these results with respect to the main parameters will be given: the vortex core radius, its distance to the rotor center and its orientation angle relative to the rotor longitudinal axis, the rotor blade begin and end of the airfoiled section, and the advance ratio.