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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 nine degrees of freedom model of articulated rotor, rigid nacelle, elastic wing, and rigid connection between nacelle and wing, considering the elastic connection between nacelle and wing, a tilting rotorcraft 11-DOF Aeroelastic Model to Analyze Rotor / Nacelle Flutter and Wing Instabilities in Forward Flight. In the establishment of rotor-nacelle-wing coupling system equations of motion, nacelle pitching and swinging The effect of motion on the rotor inertial force and Coriolis force, the influence of the nacelle motion and the gyroscopic moment generated by the rotation of the rotor, the stiffness and damping of the nacelle, the influence of the nacelle movement on the inflow of the rotor and the influence of the nacelle motion on the wing Etc. Based on the experimental model parameters, the system frequencies and damping ratios of each mode changing with the former flying speed are calculated to determine the critical speed of the system instability.By changing the influence of the nacelle support stiffness on the instability critical speed, the distinction The instability of the rotor when tilting the rotor in forward flight, that is, the vertical flutter and divergence motion of the wing or the gyratory chatter of the rotor / nacelle system, The dithering and moving images of the hub center under the instability of the wing depict the motion of the hub hub at the time when the swing chattering problem occurs.