离心叶轮流场对背压脉动的响应特性研究  

A Study on the Flow Response Characteristics to Back Pressure Pulsation of Centrifugal Impeller Flow Field

作　　者：肖军 周逸伦 张宇航 刘晓明 李奉誉 孙永瑞 刘小民[2] Jun Xiao;Yi-lun Zhou;Yu-hang Zhang;Xiao-ming Liu;Feng-yu Li;Yong-rui Sun;Xiao-min Liu(National Key Laboratory of Compressor Technology,Hefei General Machinery Research Institute;School of Energy and Power Engineering,Xi’an Jiaotong University;Shengu Group Corporation)

机构地区：[1]合肥通用机械研究院有限公司压缩机技术国家重点实验室 [2]西安交通大学能源与动力工程学院 [3]沈鼓集团股份有限公司

出　　处：《风机技术》2023年第5期34-40,共7页Chinese Journal of Turbomachinery

基　　金：合肥市自然科学基金项目(2021039);沈鼓集团-西安交大研究院专项基金项目(20210313-2KT05);国家重点研发计划资助项目(2019YFB1504601)。

摘　　要：本文首先采用数值模拟方法开展高速离心压缩机叶轮出口下游背压脉动的流场响应特性研究,分析指出高转速离心叶轮的气动性能波动随着背压脉动频率的增加而增大,但不同背压脉动频率下各时刻的流场分布具有相似结构。然后采用动态模态分解(DMD)方法对背压脉动下非定常流动的模态场进行分析,不同脉动频率下的非定常流场均包含叶轮转频的各阶谐波模态,流场响应的零阶模态为反映平均流场的基本模态,各阶谐波模态均为极限环模态,其它均为近似极限环振荡或衰减模态,流场响应的非定常成分主要由一阶谐波模态贡献。DMD分析结果表明:DMD方法能够对叶轮非定常流场变化特性进行降阶解构及准确预测。The flow field response characteristics of the back pressure pulsation downstream of the centrifugal compressor impeller outlet are firstly studied by numerical simulation.The fluctuations of aerodynamic performance parameters of the impeller rise with the increase of the frequency of back pressure pulsation,and the flow field distributions at all times under different back pressure pulsation frequencies show a similar structure.And then,the dynamic mode decomposition(DMD)method is adopted to analyze the modal field of unsteady flow under back pressure pulsation.Under different pulsation frequencies,the unsteady flow fields contain modes with the same harmonic frequencies.The zero-order mode of flow field response is the basic mode which are time constant.Each harmonic mode is a limit cycle mode,and the other modes are approximate limit cycle oscillating or attenuating modes.The unsteady components of flow field response are mainly contributed by the first harmonic mode.The results of DMD analysis show that the DMD method can realize the reduced order analysis and accurate prediction of the unsteady flow field characteristics of the centrifugal impeller.

关 键 词：高转速 离心叶轮 流场响应 背压脉动 动态模态分解 

分 类 号：TH452[机械工程—机械制造及自动化]