航空发动机双转子系统“临界跟随”现象的机理及影响  

Mechanism and effect of “critical follower speed” on dual-rotor system of aero-engines

作　　者：李岩[1] 廖明夫[1] 蒋云帆 雷新亮 王四季[1] LI Yan;LIAO Mingfu;JIANG Yunfan;LEI Xinliang;WANG Siji(School of Power and Energy,Northwestern Polytechnical University,Xi'an 710072,China;Sichuan Gas Turbine Establishment,Aero Engine Corporation of China,Chengdu 610500,China)

机构地区：[1]西北工业大学动力与能源学院,西安710072 [2]中国航空发动机集团有限公司四川燃气涡轮研究院,成都610500

出　　处：《航空动力学报》2019年第11期2403-2413,共11页Journal of Aerospace Power

基　　金：国家科技重大专项（2017-Ⅳ-0001-0038）

摘　　要：为了探明"临界跟随"现象导致航空发动机振动居高不下的产生机理,建立了考虑中介轴承的双转子动力学模型,推导了双转子发生"临界跟随"现象时参数之间的关系,分析了"临界跟随"状态下转子系统的动力学特性。结果表明:"临界跟随"现象会导致转子系统无法越过盘偏摆振型临界转速,造成转子振动对不平衡质量分布极其敏感,其主要影响因素为盘极转动惯量与直径转动惯量的比值(简称惯量比)以及双转子增速比;当高压盘等效惯量比等于1,或增速比与任意低压盘惯量比相等时,转子系统表现出高压激励条件下的"临界跟随"特征;当低压盘惯量比等于1,或增速比与高压盘等效惯量比的乘积等于1时,转子系统表现出低压激励条件下的"临界跟随"特征。提出了必须严格控制航空发动机叶盘的等效惯量比以及双转子转速控制律的设计建议。In order to investigate the mechanism of"critical follower speed"which could lead to a sustained strong vibration of aero-engine,a dual-rotor dynamic model with intershaft bearing was established.The relationship of the dual-rotor parameters in the case of"critical follower speed"phenomenon was deduced.And the dynamic characteristics of the rotor system under"critical follower speed"were analyzed.The results of investigation revealed that:the phenomenon "critical follower speed"caused the failure of rotor system to cross the critical speed of disk-swing mode,which made vibration extremely sensitive to unbalanced mass distribution of the rotor system.And there were two ratio influential factors:the ratio of polar inertia moment to the diameter inertia moment by disks(simple named"inertia ratio"),and the increasing speed ratio of dual-rotor system.When the inertia ratio of the equivalent high-pressure-disk was equal to 1,or the increasing speed ratio was equal to the inertia ratio of any low-pressure-disk,the rotor system was excited by high-pressure rotor under the"critical follower speed"state.Besides,when the inertia ratio of the low-pressure-disk was equal to 1,or the product of increasing speed ratio and inertia ratio of equivalent high-pressure-disk was equal to 1,the rotor system was excited by low-pressure rotor under the"critical follower speed"state.Additionally,it is suggested that the equivalent inertia ratio design of the blade-disk on aero-engine and the speed increasing ratio of dual-rotor should be strictly controlled.

关 键 词：双转子系统 动力学模型 临界跟随 振动幅值 固有频率 

分 类 号：V231.96[航空宇航科学与技术—航空宇航推进理论与工程]