基于流固耦合的压气机转子叶片非同步振动分析  

ANALYSIS ON NON-SYNCHRONOUS VIBRATION OF COMPRESSOR ROTOR BLADES BASED ON FLUID-STRUCTURE INTERACTION

作　　者：汪松柏 霍嘉欣 赵星 陈勇[1,2] 吴亚东 张军[1] Wang Songbai;Huo Jiaxin;Zhao Xing;Chen Yong;Wu Yadong;Zhang Jun(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;AECC Sichuan Gas Turbine Establishment,Chengdu 610500,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]中国航发四川燃气涡轮研究院,成都610500

出　　处：《力学学报》2024年第3期635-643,共9页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家科技重大专项资助项目(J2022-Ⅳ-0010-0024)。

摘　　要：压气机转子叶片非同步振动是近年来发现的一类新气动弹性问题,表现为叶片振动频率与转频不同步且具有锁频现象,严重影响航空发动机的可靠性和运行安全,目前对其产生机理并不完全清楚.为了深入研究压气机内不稳定流动与叶片非同步振动之间的耦合机制,基于时间推进的方法建立了多级压气机转子叶片全环的双向流固耦合模型,数值研究了刚性叶片与非同步振动柔性叶片的非定常流场、气流激励频率和结构响应特征,揭示了压气机转子叶片非同步振动的流固耦合机制.结果表明:近失速工况下,转子叶尖吸力面径向分离涡的周期性脱落及再附过程是导致叶尖压力剧烈波动的主要原因,其3倍谐波激励频率与转子一阶弯曲固有频率接近,提供了叶片非同步振动的初始气流激励源.叶片非同步振动发生时,位移响应表现为等幅值的极限环特征,振动以一阶弯曲模态主导,径向分离涡产生的非整数倍气流激励频率及其谐波频率最终锁定为叶片一阶弯曲固有频率,非同步振动的运动胁迫使得相邻通道叶尖流场周向趋于一致.研究成果及对叶片非同步振动流固耦合机制的认识可为压气机内部不稳定流动诱发的叶片振动失效分析提供有益参考.The non-synchronous vibration(NSV)of compressor rotor blades is a new type of aeroelastic problem discovered in recent years,the characteristics is manifested as the non synchronization between the vibration frequency and the rotating frequency and exhibiting frequency locking phenomena,which seriously affects the reliability and operation safety of aeroengine.Currently,the mechanism is not fully understood.In order to deeply investigate the interaction mechanism between the unstable flow and non-synchronous vibration of blades,a time domain fluid-structure interaction method of multistage compressor full-annulus rotor blades was established,the unsteady flow field,aerodynamic excitation frequency and structural response characteristics of rigid and flexible blades were numerically studied to reveal the fluid-structure interaction mechanism of NSV.The results indicate that the periodic shedding and reattachment process of radial separation vortices on the tip suction surface causes the severe pressure fluctuation under near stall conditions.Its three times harmonic aerodynamic excitation frequency is close to the first-order bending natural frequency and provides the initial aerodynamic excitation for the NSV.During the NSV,the displacement response of rotor blade exhibits equal amplitude limit cycle oscillation,and dominated by the first-order bending model.The non-integer multiple aerodynamic excitation and its harmonic frequencies generated by radial separation vortex are ultimately locked-in the first-order bending natural frequency.The motion stress of NSV causes the circumferential flow field of adjacent channels to become consistent.This present result and the mechanism understanding of fluid-structure interaction of NSV can provide useful references for the analysis of blade vibration failure induced by unstable flow in compressor.

关 键 词：压气机转子叶片 非同步振动 流固耦合 极限环 非定常流动 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]