半开式离心叶轮叶顶泄漏诱发流道流动堵塞特性研究  

Research on the Flow Channel Blockage Characteristics Induced by Tip Leakage of Semi-open Centrifugal Impeller

作　　者：朱俊桦 金永鑫 吕世杰[1] 成涛 宋文武 ZHU Jun-hua;JIN Yong-xin;LÜShi-jie;CHENG Tao;SONG Wen-Wu(College of Energy and Power Engineering,Xihua University,Chengdu 610039,Sichuan Province,China;Key Laboratory of Fluid and Power Machinery,Ministry of Education,Xihua University,Chengdu 610039,Sichuan Province,China)

机构地区：[1]西华大学能源与动力工程学院,四川成都610039 [2]西华大学流体及动力机械教育部重点实验室,四川成都610039

出　　处：《中国农村水利水电》2024年第1期79-85,93,共8页China Rural Water and Hydropower

基　　金：西华大学人才引进项目(Z0202042022)。

摘　　要：为探究半开式离心叶轮叶顶泄漏量诱发的流道中流动堵塞作用,采用大涡模拟对流场进行精确计算,基于流动堵塞预估模型对叶顶间隙0.5、1.0和1.5 mm的3种半开式离心叶轮在不同流量工况下的流动堵塞特性进行研究,发现在叶轮流道内存在流动堵塞峰值,且在3种叶顶间隙下均在截面2处,在经过截面2之后流动堵塞发生大幅度的减小,并在后面4个截面发生小幅度的波动;通过对不同叶顶间隙、不同流量工况下在叶轮尾缘处相对流动堵塞作用的分析,发现尾缘处的流动堵塞在不同叶顶间隙下,随流量的变化具有相同的趋势,相对流动堵塞均在1.0Q_(d)时达到最小值,在0.6Q_(d)时出现峰值;然而流动堵塞在相同流量下与叶顶间隙的关系不是单一的线性关系,且存在一个最优叶顶间隙在设计工况点达到最小的流动堵塞情况;同时通过对泄漏涡发展情况的观察,发现泄漏涡的破碎和位移会增大叶片尾缘处的流动堵塞;通过对叶片静压差的分析,发现运行流量对叶片载荷的影响不大,然而叶顶间隙的改变会大大影响叶片载荷,同时对叶片尾缘处的流动堵塞造成影响。In order to explore the blockage effect in the flow channel induced by the tip leakage of the semi-open centrifugal impeller,this paper uses the large eddy simulation to accurately calculate the flow field.Based on the blockage prediction model to investigate the blockage characteristics of three semi-open centrifugal impellers with tip clearance of 0.5,1.0 and 1.5 mm under different flow conditions are studied.The research finds that there is a blockage peak in the impeller channel,and it is at plane 2 under the three tip clearances.After passing through plane 2,the blockage is greatly reduced,and there are small fluctuations in the back four sections.Through an analysis of the rela⁃tive blockage at the trailing edge of the impeller under different tip clearances and different flow conditions,the study finds that the blockage at the trailing edge has the same change trend with the change of flow rate under different tip clearances.The relative blockage reaches the minimum at 1.0 Q_(d) and the peak at 0.6 Q_(d).However,the relationship between blockage and tip clearance is not a single linear relationship at the same flow rate,and there is an optimal tip clearance to achieve the minimum blockage at the design point.At the same time,through the observation of the development of the leakage vortex,the study finds that the fragmentation and displacement of the leakage vortex will in⁃crease the blockage at the trailing edge of the blade.Through the analysis of the static pressure difference of the blade,the study finds that the operating flow has little effect on the blade load.However,the change of the tip clearance will greatly affect the blade load and the block⁃age at the trailing edge of the blade.

关 键 词：半开式离心叶轮 大涡模拟 流动堵塞预估模型 叶顶间隙 叶片载荷 泄漏涡 

分 类 号：TH311[机械工程—机械制造及自动化]