Some Dynamic Properties of a Rigid Two-Bladed Fully Gimballed Tip-Jet Helicopter Rotor with Circulation Control.

摘要

Simplified analyses are carried out for the motions of a simple rigid two-bladed fully gimballed rectangular rotor rotating at constant speed about a stationary center point and about a center point translating at a low constant advance ratio. (The term 'fully gimballd' means that hub moments about all axes are zero.) It is concluded that: The rotor can be rendered dynamically stable by appropriate mass balancing. In a particular example considered, the mass balancing was estimated to increase the rotor weight by about 20%. The steady state motion about a translating center due to first harmonic moments induced by translation is a wobbling motion with the principal axis of rotation describing a cone about its mean position at twice the rotor rotational frequency. A circulation control system can control total rotor lift and can cause precession of the mean position of the principal rotational axis to any desired orientation. It cannot, however, influence the amplitude of the steady state wooble.