热致混合式转子变结构与动力学特性

航空发动机、汽轮机等大型旋转机械多运行在复杂多变的高温环境中，机组主转子系统在工况下因热膨胀而产生结构变化，进而影响运行特性。首先，考虑盘鼓混合式旋转构件与转轴相比具有高刚度特点，将其结构简化并建立单厚盘转子动力学模型；其次，针对热膨胀引发的系统变结构特征，以曲线拟合结合Hermite插值法描绘出圆柱厚盘窜动到任意位置时的转轴弯曲情况，根据弯曲轴所储存的弹性势能运用数值方法折算出对转盘所提供的恢复力及转轴的弯曲恢复刚度；最后，通过数值分析热膨胀诱发的轴向窜动对厚盘转子系统进动频率、临界角速度和振动响应幅值等动力学特性的影响，验证了热膨胀诱发的转轴窜动因素是影响厚盘转子系统动力学特性的主要因素之一。 

Variable structure and dynamics properties of mixing rotor due to thermal expansion

According to complex and changeable high-temperature environments of large rotating machinery, such as aero engines or steam turbines, the main rotor system of the unit has a variable structure due to thermal expansion under operating conditions, which could also affect the operation characteristics. First, considering high stiffness of turntable-drum mixing, compared with the rotating shaft, the structure is simplified and a single-thickness disk rotor dynamic model is established. Second, aimed at the variable structure characteristics of the system caused by thermal expansion, Hermite interpolation method and curve fitting method are used to depict the bending condition of rotating shaft when the thickness table is at any position, and then bending restoring force provided to disk and the bending restoration stiffness of the shaft are calculated by using numerical methods, basing on elastic potential energy stored in the bending.Finally, through numerical analysis of precession frequency, critical angular velocity and response amplitude of thick disk rotor system, it is verified that axial movement induced by thermal expansion is one of the main factors that affect the dynamics properties of thick disk rotor system.