半开式离心叶轮与扩压器间流动模态提取与分析  

DMD Analysis of the Flow in an Unshrouded Impeller and Diffuser

作　　者：邵昱昌 王彤[1] Yu-chang Shao;Tong Wang(School of Mechniacal Engineering, Shanghai Jiao Tong University)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《风机技术》2017年第4期1-7,共7页Chinese Journal of Turbomachinery

基　　金：国家自然科学基金资助项目(51276108)

摘　　要：考虑到半开式离心叶轮叶顶间隙流动对离心压缩机流动稳定性的影响,本文采用动态模式分解的方法对比了离心叶轮和无叶扩压器分别在设计工况和近失速工况下的流动结构及其频率信息。结果表明:叶轮出口附近的叶顶间隙流动对无叶扩压器中流动有显著影响,无叶扩压器中出现了和叶顶泄漏流流动相关的涡结构。随着流量的减小,叶顶间隙流动进一步影响无叶扩压器内部流动,涡结构频率变高,径向直径减小并向动静交界面移动,同时靠近盘侧的流场出现不稳定流动趋势。The tip clearance has a large impact on the flow stability of centrifugal compressors.In this paper the flow fieldin the impeller and vaneless diffuser is investigated with dynamic mode decompositioning to compare the frequency and theflow structures in the design and near stall operating conditions.The results confirm that the tip leakage flow affects the flowstructure in the vaneless diffuser.The vortex is generated by the tip leakeage flow in the impeller and propagates into thevaneless diffuser.For mass flow rates lower than in the design condition,the influence of the tip leakage flow is morepronounced and the frequency of the vortex becomes higher.The radial diameter of the vortex is reduced and the vortex coremoves closer to the impeller.This unstable phenomenon occurs close to the hub.

关 键 词：离心式压缩机 叶顶间隙 无叶扩压器 动态模式分解 

分 类 号：TH452[机械工程—机械制造及自动化] TK05[动力工程及工程热物理]