倾转旋翼过渡状态瞬态响应分析与试验

Analysis and Experiments of the Tiltrotor Transient Response During Transition Flight

基于多体动力学分析方法建立倾转旋翼过渡状态瞬态响应分析模型,研究过渡状态下倾转旋翼非线性非定常气弹耦合动力学特性;通过引入倾转过程旋翼尾迹弯曲的影响,修正了直升机旋翼常规动态入流模型。集成非定常动态入流方程与倾转过渡状态的多体动力学方程,建立倾转旋翼过渡状态下时域非定常耦合分析模型。以两片桨叶的跷跷板旋翼为例,分析倾转过渡状态旋翼瞬态挥舞响应及旋翼气动力的时间响应历程。利用旋臂式模型机动飞行试验机进行倾转过渡状态下旋翼瞬态拉力的试验研究,试验与理论计算结果表现出很好的相关性。数值计算和试验结果表明:建立的时域模型能够有效分析倾转旋翼过渡状态的瞬态特性;倾转过渡状态旋翼尾迹弯曲对非定常动态入流的影响是显著的,对于倾转过渡状态动态入流尾迹弯曲的修正是很必要的。

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.