混流泵启动过程瞬态流场的涡动力学分析  

Vortex dynamics analysis of transient flow field at starting process of mixed-flow pump

作　　者：李伟[1] 季磊磊 张扬[1] 施卫东 杨勇飞[1] LI Wei;JI Leilei;ZHANG Yang;SHI Weidong;YANG Yongfei(National Research Center of Pumps and Pumping System,Jiangsu University,Zhenjiang 212013,China;College of Mechanical Engineering,Nantong University,Nantong 226019,China)

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013 [2]南通大学机械工程学院,江苏南通226019

出　　处：《中南大学学报（自然科学版）》2018年第10期2480-2489,共10页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51679111;51579118;51409127);国家重点研发计划项目(2017YFC0403703);江苏省重点研发计划项目(BE2015119;BE2015001-4;BE2016319;BE2017126);江苏省自然科学基金资助项目(BK20161472);江苏高校优势学科建设工程资助项目(PAPD)~~

摘　　要：为了深入分析混流泵启动过程的瞬态流动结构,研究启动过程叶轮内部能量分布特性及其对瞬态性能的影响,基于正则化螺旋度法提取瞬态流场涡核,对启动过程进口段、叶轮和导叶段内部流动进行涡结构分析,并运用过流断面诊断法对混流泵启动过程内部流动进行诊断。研究结果表明:进口观测截面流场的涡核结构受叶轮叶片数的影响较大,涡核总体呈现从分散到集中的演化过程;随着转速增加,叶轮内涡结构正向和反向涡交替变化,并在转速稳定后流动逐渐趋于稳定;导叶内的涡结构在启动初期呈非对称性分布,当转速稳定后,涡结构区域逐渐减少并呈现规律性分布,流体流动趋于稳定。在混流泵启动过程中,随着叶轮旋转加速,总压流随之迅速增大,叶轮对流体做功,流体获得的能量迅速增加;由于流体惯性,加速末期流体获得了大于稳态转速下的能量,这种瞬态效应的外部体现就是在加速末期泵装置获得了瞬时冲击扬程。In order to further analyze the transient flow structure of the mixing pump at the start-up process and research the energy distribution in the impeller during the start up period as well as its effect on the transient characteristic of mixed-flow pumps,vortex core of transient flow field was extracted based on the regularized helical method.The vortex structure in the pump inlet,impeller and the guide vane was then analyzed and diagnosed through the information on the flow section method.The results show that the vortex structure on the section of the inlet is greatly affected by the blade number of impeller and the vortex concentrates from different directions.With the increase of the rotating speed of impeller,the positive and negative vortexes appear alternately and tend to be stable when the speed reaches the rated speed.The vortex structure in the guide vane is distributed asymmetrically;the vortex region shrinks and is regularly distributed when the speed becomes stable.During the start up period of mixed-flow pump,the total pressure increases quickly with the increase of the rotating speed.Due to the work of impeller,the energy of fluid increases rapidly.As a result of the inertial force of fluid,the energy of fluid is higher than that in stable working condition.The external appearance of such a transient effect is that there is a shock head at the end of the accelerating process.

关 键 词：混流泵 启动过程 瞬态流场 涡结构 涡动力学 

分 类 号：TH313[机械工程—机械制造及自动化]