摘要
由转静干涉引起的非定常流动是造成叶片/叶盘强迫响应的主要激励来源,更加准确和全面地表征转静干涉非定常流场的时空分布特征对流固耦合振动分析具有重要的意义,利用本征正交分解(POD)和动力学模态分解(DMD)等模态分析方法可以有效地从复杂流动系统中识别和提取激励成分.该文以典型的1.5级涡轮平面叶栅为例,采用POD方法和DMD方法获得二维转静干涉流场的流动模态和时间系数,对叶片通道流场的时空分布特性进行分析.结果表明:两种模态分解方法均能有效辨识流动特征,实现流场的合理减缩.利用模态能量排序的POD方法可以准确识别占据流场主导地位的流动结构;而基于频率特征的DMD方法可以快速识别流场中各阶模态对应的激振频率和激励阶次.模态分解方法相较于传统FFT方法,不受采样位置的影响,兼顾全场流动识别和局部特征分析,可为叶轮机械非定常激励耦合振动快速分析提供帮助.
The unsteady flow caused by the rotor-stator interaction is the primary excitation source for the forced response of the blade/blisk.A more accurate and comprehensive characterization of the spatiotemporal features of the rotor-stator interaction unsteady flow field is of significance for the analysis of fluid-structure interaction vibrations.The typical modal analysis methods such as the proper orthogonal decomposition(POD)and the dynamic mode decomposition(DMD)were employed to effectively identify and extract the excitation components from complex flow systems.With a 1.5-stage turbine cascade as the example,the POD method and the DMD method were used to obtain the flow modes and temporal bases of the 2D rotor-stator interaction flow field,and analyse the spatiotemporal characterization of the blade channel.The results show that,the both modal decomposition methods can effectively identify the flow characteristics and realize the reasonable reduction of the flow field.The POD method,with the modal energy ranking,can accurately identify the dominant flow structures in the flow field.Meanwhile,the DMD method based on frequency characteristics can rapidly pinpoint the excitation frequencies and engine orders of each mode in the flow field.Compared to the fast Fourier transform(FFT)methods,the modal decomposition techniques are not influenced by the sampling locations and effectively combine full-field flow recognition with local feature analysis.This approach facilitates swift analysis of unsteady excitation-coupled vibrations in turbomachinery.
作者
周向鑫
李滕
杨维建
林永康
张涛
姚建尧
ZHOU Xiangxin;LI Teng;YANG Weijian;LIN Yongkang;ZHANG Tao;YAO Jianyao(College of Aerospace Engineering,Chongqing University,Chongqing 400044,P.R.China;Research Institute of Aero-Engine,Beihang University,Beijing 102206,P.R.China;Taihang Laboratory,Chengdu 610213,P.R.China)
出处
《应用数学和力学》
北大核心
2025年第2期223-240,共18页
Applied Mathematics and Mechanics
基金
国家科技重大专项(J2022-IV-0010-0024)
中央高校基本科研业务费(2023CDJXY-007)。
关键词
瞬态流场
本征正交分解
动力学模态分解
转静干涉
非定常激励
transient flow field
proper orthogonal decomposition
dynamic mode decomposition
rotor-stator interaction
unsteady excitation
作者简介
周向鑫(1993-),男,硕士生,E-mail:xiangxinzhou@cqu.edu.cn;通讯作者:姚建尧(1981-),男,教授,博士,博士生导师,E-mail:yaojianyao@cqu.edu.cn.
