多跨转子系统流体引发自激振动稳定性分析  

Stability of a multi-span rotor system with fluid-induced self-excited vibration

作　　者：赵倩[1] 许琦[1] 姚红良[1] 闻邦椿[1] 

机构地区：[1]东北大学机械工程与自动化学院,沈阳110819

出　　处：《振动与冲击》2016年第5期196-200,共5页Journal of Vibration and Shock

基　　金：国家重点基础研究发展计划项目(2011CB706504);国家自然科学基金资助项目(51475085);研究生科研创新项目(N140306003)

摘　　要：以实际压缩机组多跨转子系统为研究对象,针对由间隙气流激振力引起的失稳问题,进行Alford力作用下多跨转子系统的动力学及稳定性分析。针对该类模型自由度多的特点,采用固定界面模态综合法降维措施与Newmark-β法相结合,提高了求解效率。研究交叉刚度、工作转速等对转子涡动的影响,以及多跨转子系统中Alford力的传递作用;通过以时间历程曲线为稳定性判据,进行不同交叉刚度、阻尼、刚度系数下的稳定性分析。结果表明,交叉刚度的增大会加重转子涡动,降低系统的稳定性;系统阻尼和刚度的增大可提高稳定性;失稳交叉刚度与支承的交叉刚度存在一定关系,当其大于支承最小交叉刚度且接近支承最大交叉刚度时,系统容易失稳。Turbine rotor systems may lose stability due to Alford forces. Here,dynamic characteristics and stability of a multi-span rotor system for a practical compressor unit subjected to Alford forces were investigated. Newmark-βmethod combined with the fixed interface component mode synthesis（ CMS） dimension reduction approach due to many degrees of freedom of a large scale rotor system was applied to obtain the system＇s dynamic response. The computational efficiency was improved obviously. The effects of cross stiffness and rotating speed on rotor whirling and the transmission action of Alford forces in the multi-span rotor system were studied. Taking the system＇s time historv response as a stability criterion,stability analysis with different dynamic parameters was performed. It was shown that the rotor whirling aggravates and its stability decreases with increase in cross stiffness; its stability is improved with increase in the system＇s damping and stiffness; when the cross stiffness of the system are larger than the minimum cross stiffness of bearings and close to the maximum cross stiffness of bearings,the system is easy to be unstable.

关 键 词：多跨转子 Alford力 交叉刚度 自激振动 稳定性分析 

分 类 号：TH113.1[机械工程—机械设计及理论] O323[理学—一般力学与力学基础]