A critical examination of the flap-lag dynamics of helicopter rotor blades in hover and in forward flight

摘要: A critical examination of flap-lag stability a centrally hinged, spring-restrained rigid blade in both hover and forward flight is presented. Several differences the equations motion for existing literature are identified. rigorous systematic development these articulated shows existence some linear aerodynamic coupling terms associated with steady-state flapping lagging perturbation equations. The identified shown to be order which flap lag transformations taken developing motion. implications on examined, it that pitch-lag hinge transformation sequence have marked influence stability. Some qualitative considerations role assumed hingeless elastic also given. On basis considerations, similar those found will appear blade.