基于临界转速与振型相似的涡轴发动机模拟转子实验台设计方法  

Design method of the simulated-rotor test rig for the turboshaft engine based on the critical speed and the similarity of vibration mode

作　　者：廖子豪 宾光富[1] 李超 袁巍 LIAO Zi-hao;BIN Guang-fu;LI Chao;YUAN Wei(School of Mechanical Engineering,Hunan University of Science and Technology,Xiangtan 411201;AECC Hunan Aviation Poweqilant Research Institute,Zhuzhou 412002)

机构地区：[1]湖南科技大学机电工程学院,湖南湘潭411201 [2]中国航发湖南动力机械研究所,湖南株洲412002

出　　处：《机械设计》2021年第6期45-50,共6页Journal of Machine Design

基　　金：国家自然科学基金资助项目(51775030,52075165);湖南省自然科学基金资助项目(2019JJ40084);湖南省教育厅科学研究重点资助项目(19A171);湖南省研究生科研创新项目(CX20190806)。

摘　　要：针对涡轴发动机由于燃发转子零部件多、转速高、流固热耦合导致振动特性复杂,难以通过整机试验揭示振动特性机理的问题,在结构相似的基础上,采用相似设计基本理论,提出通过各阶临界转速之比相等和振型相似的涡轴发动机模拟转子实验台的设计方法。首先阐述了相似设计理论并推导出转子系统质量、刚度和固有频率之间的相似关系表达式。然后以某型涡轴发动机燃发转子模拟实验台设计为例,在其工作转速的基础上,依照各阶临界转速之比相等与振型相似的设计原则,对涡轮盘、转轴、弹性支撑等模拟转子结构件进行反求等效设计,从而构建出同原型机动力学特性相似的模拟转子有限元模型,分析其前3阶临界转速及对应的振型,与原型机相应临界转速值最大误差为3.5%。最后通过试验测试该模拟转子实验台临界转速与振动响应,验证了该相似设计方法的正确性。该方法可拓展到类似转子结构的设计过程。The turboshaft engine’s gas-generating rotor has such setbacks as many parts,high speed,and fluid-solid thermal coupling,which leads to complex vibration characteristics;it is difficult to reveal the mechanism of vibration characteristics by means of any test on the whole machine. In this article,based on the principle of structural similarity,the theory of similarity design is applied and the design method of the simulated-rotor test rig with equal ratios of critical speed and similar vibration modes is worked out. Firstly,efforts are made to derive the expression of the similarity relationship among the rotor’s mass,stiffness and natural frequency. Then,with the design of the gas-generating simulated-rotor test rig as an example,on the basis of its working speed,according to the design principle that the ratio of the critical speed of each order is equal to the vibration mode,the rotor’s structural parts such as the turbine disk,the rotating shaft,the elastic support are subject to the reverse equivalent design,in order to set up the finite-element model for the simulated rotor,which is in line with the of the prototype’s dynamic characteristics. Besides,the analysis is conducted on both the critical speed at the first three stages and the related vibration modes. The maximum error of the critical speed corresponding with the prototype is 3. 5%. Finally,both the critical speed and the vibration response of the simulated rotor test rig are verified through a series of experiments,and it’s proved that this similarity-based design method is correct. It can be further applied to the design process of rotor-like structures.

关 键 词：动力学相似 临界转速 振型 有限元模型 涡轴发动机转子 

分 类 号：V219[航空宇航科学与技术—航空宇航推进理论与工程]