非设计工况下带分流叶片半开式离心叶轮内部流动特性数值研究  

Numerical Study on the Internal Flow Characteristics of an Unshrouded Centrifugal Impeller with Splitter Blades at Off-design Conditions

作　　者：曾永顺 刘连强 郝晓林 姚志峰 王福军 杨敏 Yong-shun Zeng;Lian-qiang Liu;Xiao-lin Hao;Zhi-feng Yao;Fu-jun Wang;Min Yang(College of Water Resources&Civil Engineering,China Agricultural University;Beijing Aerospace Petrochemical Technology and Equipment Engineering Corporation;Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System)

机构地区：[1]College of Water Resources&Civil Engineering,China Agricultural University [2]Beijing Aerospace Petrochemical Technology and Equipment Engineering Corporation [3]Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System

出　　处：《风机技术》2021年第2期12-20,共9页Chinese Journal of Turbomachinery

基　　金：National Natural Science Foundation of China(No.51836010,51879266 and 51839001);the Beijing Municipal Science and Technology Project(No.Z181100005518013).

摘　　要：In order to investigate the complex flow characteristics inside an unshrouded centrifugal impeller with splitter blades at off-design conditions,and analyze its influence on pump operation stability,a numerical simulation study was carried on using the curvature-corrected SST-CC turbulence model;the head and efficiency accorded with experimental results.The pressure fluctuation,unsteady radial force and velocity were analyzed quantitatively and the numerical results indicate this:the peak to peak value of pressure fluctuation in the impeller channel gradually increases in the flow direction and at 0.49Qn,the slope of peak to peak value to normalized impeller channel behind the splitter blade is 8.57 times greater than that before the splitter blade.The greater the flow rate deviates from the design condition,the larger the peak to peak value of the pressure fluctuation and radial force;in particular at 0.27Qn,the maximum radial force is 194.29%greater than that of the design condition.When the operating flow rate is smaller than 0.83Qn,the stall occurs and the stall vortex could block the impeller discharge;as the flow rate decreases further,the pressure amplitude at rotational frequency gradually increases in the impeller channel and the prevailing frequency changes from the blade passage frequency(BPF)to the rotating stall frequency in the diffuser.The tip leakage vortex(TLV)is generated in the tip region and rotated move downstream in the impeller flow channel,and the backflows appear on the blade suction side and in the tip and the tongue regions;the smaller the flow rate,the more serious the TLV and backflow phenomenon.The rotating stall causes uneven flow in the impeller channel,increasing the pressure fluctuation and the radial force,and resulting in an imbalance of the impeller rotation.

关 键 词：Off-design Condition Splitter Blade Unshrouded Centrifugal Impeller Pressure Fluctuation Radial Force 

分 类 号：TH38[机械工程—机械制造及自动化]