空化对离心泵叶轮径向力及压力脉动的影响  

Effects of cavitation on the radial force and pressure pulsation of a centrifugal pump

作　　者：谢航 冯建军[1,2] 罗兴锜[1,2] 闫思娜 朱国俊[1,2] 王李科 王维 XIE Hang;FENG Jianjun;LUO Xingqi;YAN Sina;ZHU Guojun;WANG Like;WANG Wei(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China;Institute of Water Resources and Hydro-electric Engineering,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,西安710048 [2]西安理工大学水利水电学院,西安710048

出　　处：《农业工程学报》2025年第4期32-39,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(52439006,52206054,52309118);陕西省自然科学基金项目(2023-JC-QN-0446);西安理工大学博士创新基金项目(310-252072209)。

摘　　要：不稳定空化流动会诱发离心泵内发生高幅值压力脉动并加剧泵体振动,影响其安全稳定运行。该研究以闭式离心泵为研究对象,通过非稳态数值模拟探究了设计流量下叶轮径向受力及压力脉动随空化发展的变化规律,分析了空泡变化对压力脉动的影响。研究结果表明:随着空化的发展,叶轮径向力先减小后增大,变化拐点为前盖板附近出现游离片状空化;完全空化状态下径向力呈多边形分布,大小约为无空化状态的1.4倍;不同空化状态下,叶轮径向力变化频率以转频f_(n)及其倍频为主。压力脉动突增发生在空泡团破碎阶段;不同空化状态下,监测点压力脉动主频均为转频fn;严重空化时,空泡团的缓慢演化会在下游诱发0.5fn的低频压力脉动。研究结果可为离心泵空化监测和诊断提供参考。Cavitation is one kind of complex multiphase flow.Unstable cavitation flow can often induce a high amplitude of pressure pulsation,leading to the vibration of the pump body inside the centrifugal pump.A threat can also be posed to the safety and stability of pump operation.This study aims to explore the variation in the radial force and the pressure pulsation of the impeller,as the cavitation developed.A closed centrifugal pump was taken as the research object.Unsteady numerical simulation was carried out to investigate the cavitation flow in the centrifugal pump under a given flow rate.The homogeneous Eulerian-Eulerian two-fluid model was used to simulate the cavitation flow.Two-equation SST(shear stress transmission)k-ωmodel was adopted as the turbulence model to close the URANS(unsteady reynolds averaged navier-stokes)equations.The Schnerr-Sauer cavitation model was used to solve the volume fraction of the vapor phase.The reliability of the model and numerical simulation was verified to compare with experimental values.A systematic analysis was made to determine the influence of vapor bubbles on radial force and pressure pulsation.The research results indicated that the time-averaged radial force on the impeller first slightly decreased and then suddenly increased as the cavitation developed.The turning point was observed in the condition that the sheet cavitation appeared near the shroud.Furthermore,the time-averaged radial force reached as high as 60.5 N under complete cavitation,which was 1.4 times higher than under non-cavitation.And the peak value of radial force reached the maximum of 120 N,which was 1.69 times that of no cavitation stage.The high amplitude radial force caused the pump body more prone to instantaneous large vibration.The presence of bubbles disrupted the symmetry of pressure distribution,resulting in a polygonal distribution of radial force.The frequency of radial force variation was dominated by the impeller rotational frequency and its multiplication under different cavitation states.

关 键 词：离心泵 空化 数值模拟 压力脉动 径向力 

分 类 号：TH311[机械工程—机械制造及自动化]