涡轮增压器转子系统的模态分析和临界转速计算

Modal Analysis and Critical Speed Calculations of Turbocharger Rotor Systems

对涡轮增压器转子系统分别采用三维实体模型法和一维梁单元模型法进行了模态分析和临界转速计算,得到了其固有频率、临界转速及各阶振型。结果显示:三维实体模型法计算出的各阶振型与一维梁单元模型法得到的结果相同,但固有频率和临界转速略高于一维梁单元模型法得到的结果,说明三维实体模型的刚度大于一维梁单元模型的刚度。对临界转速和滑动轴承油膜刚度的关系进行了计算,计算结果表明:刚度在一定范围内,临界转速避开了涡轮增压器的工作转速。

Using the method of three-dimensional solid model and one-dimensional beam element respec- tively to carry out modal analysis and critical speed calculations of turbocharger rotor system, its natural frequency, critical speed and the vibration mode were obtained. The results showed that the vibration mode calculated by three-dimensional solid model method was the same as the one calculated by one-di- mensional beam element modal, but the natural frequency and critical speed were slightly higher than the one-dimensional beam element model results, which meant that the stiffness of three-dimensional solid model was greater than the one-dimensional beam element model. Moreover, the relationship between the film stiffness of sliding bearing and the critical speed was calculated, the results showed that within a cer- tain range of stiffness, the critical speed was out of the turbocharger＇ s operating speed range.