Contact analysis of a flexible bladed-rotor
Contact analysis of a flexible bladed-rotor
复制标题
DOI：
10.1016/j.euromechsol.2006.11.002
复制
发表时间：
2007-05
影响因子：
4.1
通讯作者：
N. Lesaffre;J. Sinou;F. Thouverez
中科院分区：
文献类型：
--
作者：
N. Lesaffre;J. Sinou;F. Thouverez
本文提出了一种基于旋转机架的全柔性叶片转子模型。采用能量法得到了系统动力学特性的矩阵方程。模型考虑了陀螺效应、自旋软化效应和离心加劲效应，并考虑了预应力势。在旋转坐标系中，后一矩阵方程的特征值虚部给出了系统的Campbell图，通过其相关的特征值实部分析了系统的稳定性。采用能量法对涡轮机壳进行了建模，并在旋转框架中加入了一个弹性环。因此，在某些转速范围内，转子和定子之间的接触问题可以视为静态问题，因为这两个结构彼此是静止的。在研究转子柔性叶片与柔性机匣接触的完整问题之前，为了强调散度不稳定性和模态耦合，在旋转框架中也建立了一个受旋转载荷激励的只有一种模态振型的弹性环的简单模型。然后，研究了叶片与机匣无摩擦滑动接触的完全问题。得到了结构稳定平衡的静接触构型与转子转速的关系。最后，将计算结果与弹性环上旋转弹簧质量的简单模型进行了比较，表明该模型具有较好的充分性。因此，目前的转子模型似乎特别适合于叶片-机匣接触的研究，并突出了即使在无摩擦滑动的情况下，在定子临界转速附近也存在不稳定现象。
This paper presents a model of fully flexible bladed rotor developed in the rotating frame. An energetic method is used to obtain the matrix equations of the dynamic behaviour of the system. The gyroscopic effects as well as the spin softening effects and the centrifugal stiffening effects, taken into account through a pre-stressed potential, are included in the model. In the rotating frame, the eigenvalues' imaginary parts of the latter matrix equation give the Campbell diagram of the system and its stability can be analysed through its associated eigenvalues' real parts. The turbo machine casing is also modelled by an elastic ring in the rotating frame through an energetic method. Thus, in some rotational speed ranges the contact problem between the rotor and the stator can be treated as a static problem since both structures are stationary to each other. Prior to the study of the complete problem of contact between the flexible blades of the rotor and the flexible casing, a simple model of an elastic ring having only one mode shape, excited by rotating loads is developed in the rotating frame too, in order to underline divergence instabilities and mode couplings. Then, the complete problem of frictionless sliding contact between the blades and the casing, without rubbing, is studied. The stable balanced static contact configurations of the structure are found as function of the rotational speed of the rotor. Finally, the results are compared to these of the simple model of rotating spring-masses on an elastic ring, showing good adequacy. The present model of rotor appears thus particularly adapted to the study of blades-casing contacts and highlighted an unstable phenomenon near the stator critical speed even in case of frictionless sliding.