基于非定常空化流动的离心泵涡旋结构数值分析  

Numerical Analysis of Vortex Structure in Centrifugal Pump Based on Unsteady Cavitation Flow

作　　者：伍杰 邱宁[1] 朱涵 徐佩 司乔瑞[1] WU Jie;QIU Ning;ZHU Han;XU Pei;SI Qiaorui(Research Center of Fluid Machinery Engineering and Technology,Jiangsu University,Zhenjiang 212013 China)

机构地区：[1]江苏大学流体机械工程技术研究中心,江苏镇江212013

出　　处：《西华大学学报（自然科学版）》2023年第1期90-99,共10页Journal of Xihua University:Natural Science Edition

基　　金：国家自然科学基金项目(51806082);江苏省“双创博士”项目(18SCBS016);中国博士后科学基金面上项目(2020M671363);中国博士后科学基金特别资助项目(2021T140282);江苏省博士后科研资助计划项目(2020Z298)。

摘　　要：为了明晰空化流场涡旋结构的形成机理及流动影响,采用数值模拟方法对一台离心泵进行非定常空化流动仿真,基于速度分量分析截面二维涡旋结构,对叶片表面涡量进行数值提取,对比讨论其周期性的演变过程,同时还应用新Omega(Ω)涡识别方法对叶轮流道三维涡旋结构进行分析。结果表明:随着汽蚀余量的降低,空化覆盖面积增大,泵内流动变得紊乱,形成局部旋涡;由于空化流场影响,涡旋结构主要在叶片吸力面生成并演变,在临界空化时,涡旋还会随着空腔的卷起而脱离叶片表面;在动静干涉作用之下,叶片尾迹涡脱落并附着于隔舌前端的蜗壳壁面;基于新Omega涡方法捕捉到空腔内部的三维涡旋结构稳定,在临界空化条件下叶轮流道下游三维涡旋结构破碎且紊乱。To elucidate the formation mechanism of the vortex structure in cavitation flow, the unsteady cavitation flow field of the centrifugal pump was investigated by simulation. The two-dimensional vortex structure on the mid-section was examined based on the method with velocity components. The vorticity on the blade surface and the evolution of the periodicity was compared. In addition to investigate the three-dimensional vortex structure in the impeller passage, the new Omega vortex identification method was also utilized. The results show that: as the NPSHa decreases, the cavity coverage area grows progressively, and the local vortices emerge and the flow in the pump becomes disordered. Due to the effect of cavitation flow field, the vortex structure is mostly formed and evolved on the blade suction surface. During the critical cavitation, the vortex is also detached the blade surface as the cavity rolls up. At the effect of rotor-stator interaction, the blade trailing vortex sheds and attaches to the volute wall at the front end of the tongue. According to the Omega method, the structure of the three-dimensional vortex within the cavity is stable. At the critical cavitation condition, the structure of the three-dimensional vortex downstream of the impeller passage is fragmented and disordered.

关 键 词：离心泵 数值模拟 空化 Omega涡方法 动静干涉 

分 类 号：TH311[机械工程—机械制造及自动化]