论文部分内容阅读
基于有限元方法建立了叶轮的动力方程和N阶自由度系统的自由振动微分方程,并对方程中非线性初应力刚度矩阵进行了线性简化;应用Ansys有限元软件对透平膨胀机工作状态下的闭式叶轮和半开式叶轮分别进行了带有预应力结构的模态分析,得到了其在惯性力作用下的振动特性和振动形式;同时对不同转速下闭式叶轮的模态进行了计算分析.结果表明:叶轮离心力的刚化作用对振动频率的影响较为显著;由于离心力的刚化作用,叶轮的固有频率比静频时有所提高;随着转速的提高,叶轮的振动频率也随之加快.
Based on the finite element method, the impeller dynamic equations and N-order free-standing differential equations are established and the nonlinear initial stress stiffness matrices are linearly simplified. The Ansys finite element software is used to analyze the turboexpander The closed impeller and the semi-open impeller are respectively subjected to the modal analysis with the prestressed structure. The vibration characteristics and vibration of the impeller are obtained under the action of inertial force. At the same time, the modes of the closed impeller under different rotational speeds The results show that the influence of the impeller centrifugal force on the vibration frequency is significant. The centrifugal impeller stiffness increases the natural frequency of the impeller more than the static frequency. As the rotational speed increases, the vibration frequency of the impeller also increases Accompanied by faster.