摘要
在铰接式旋翼、刚性短舱、弹性机翼、短舱与机翼之间刚性连接假设的Johnson九自由度模型基础上,考虑短舱与机翼之间的弹性连接,建立了倾转旋翼机前飞时分析旋翼/短舱回转颤振和机翼不稳定性的十一自由度气弹动力学模型.在建立旋翼/短舱/机翼耦合系统运动方程时,考虑了短舱俯仰和摆动运动对旋翼惯性力和哥氏力的影响、短舱运动和旋翼旋转产生的陀螺力矩的影响、短舱支撑刚度与阻尼的影响、短舱运动对旋翼入流变化的影响以及短舱运动对机翼运动的影响等.根据试验模型参数,计算了各模态随前飞速度变化的系统频率和阻尼比以确定系统失稳的临界速度.通过改变短舱支撑刚度对失稳临界速度的影响,区分倾转旋翼机前飞时的失稳形式,即机翼的垂向颤振发散运动或旋翼/短舱系统的回转颤振.通过绘制的旋翼桨毂中心运动轨迹,揭示了倾转旋翼机回转颤振和机翼变形失稳下桨毂中心的运动图像,直观描述了回转颤振问题发生时桨毂中心的运动形态.
Based on the Johnson＇s model of tiltrotor aircraft with nine degrees of freedom containing the assumptions of articulated rotor, rigid nacelle, elastic wing and clamped connections between the nacelle and wing, and considering the elastic connections between the nacelle and wing, the aeroelastic model of tiltrotor aircraft with eleven degrees of freedom for analysis of the whirl flutter of rotor/nacelle and instability of wing in forward flight has been established in this paper. The influences of the nacelle pitching and swing on the rotor inertial force and Coriolis force, the gyroscopic moment produced by the nacelle motion and rotor rotation, the supporting stiffness and damping of nacelle, the influence of nacelle motion on change in inflow of rotor and the influence of nacelle motion on wing motion have been considered in establishing the equations of motion of the rotor/nacelle/ wing coupled system. By using the system parameters of experimental model, the modal frequencies and damping ratios changing with the flight speed were calculated to determine the critical instability speed of the system. By influence of change in the supporting stiffness of nacelle on the critical instability speed, the dynamic instability form of tiltrotor aircraft in forward flight such as the vertical divergence motion of wing flutter or the whirl flutter of rotor/nacelle can be determined. According to the drawn motion trajectories of rotor hub center, the motion images of rotor hub center in the conditions of whirl flutter and wing instability of tiltrotor aircraft can be revealed, intuitively describing the motion patterns of rotor hub center in occurrence of the whirl flutter.
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2014年第3期286-294,共9页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:10832001)资助项目
关键词
倾转旋翼机
回转颤振
运动图像
tiltrotor aircraft, whirl flutter, motion image
