Analysis and Experiments of the Tiltrotor Transient Response During Transition Flight

The time domain analytical model of the tiltrotor transient response during transition flight was described.Based on multi-body analysis,the equations of motion were derived.The effects of rotor wake curvature on induced velocity were considered to improve the dynamic inflow model of the tiltrotor during transition flight.The multi-body dynamic differential equations were combined with the equations of the unsteady dynamic inflow model to obtain the complete time domain unsteady coupling analytical model of the tiltrotor.Using the 2-blade teetering rotor as an example,the transient responses of the tiltrotor during transition flight were calculated.The experiment of transient rotor thrust during transition flight has been carried out on whirling beam test facility,and the experimental results show excellent agreement with theory.The experimental results and the numerical simulations demonstrate that the time domain analytical model derived in this paper has a capability of capturing the transient characteristics of tiltrotor during transition flight.The effects of wake curvature on unsteady dynamic inflow of tiltrotor are considerable and the modification to the unsteady dynamic inflow is necessary.