离心泵非定常空化流场及空泡特征分析  

Analysis of Unsteady Cavitation Flow Field and Cavitation Bubble Characteristics for a Centrifugal Pump

作　　者：王东伟[1,2] 刘在伦 曾继来[1] Wang Dongwei;Liu Zailun;Zeng Jilai(School of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Fluid Machinery and Systems,Gansu Province,Lanzhou 730050,China)

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050 [2]甘肃省流体机械及系统重点实验室,兰州730050

出　　处：《流体机械》2020年第12期28-35,42,共9页Fluid Machinery

基　　金：国家自然科学基金资助项目(51269010);甘肃省自然科学基金项目(1508RJYA077)。

摘　　要：为了揭示空化条件下离心泵叶轮内不稳定流场特性,采用数值模拟与试验相结合的研究方法,对离心泵叶轮内部空化流动进行了定常与非定常数值计算。结果表明:数值计算与试验得到的外特性曲线吻合较好;空化初生区域位于叶片背面靠近进口边附近,在空化发展过程中每个流道内部空泡含量并不相同;平衡孔处空化发生时间较迟,此处空泡生长独特并未发生扩散与转移;随着空化数的降低,空泡集中区域由后盖板附近向前盖板附近转移;空泡的发展对叶片背面压力的影响远大于工作面;叶轮各监测点压力脉动频谱具有典型的离散特征,压力脉动峰值出现在叶片通过频率fp及其高次谐波nfp处,压力脉动强度沿径向不断增强;随着空化数的减小空泡对压力脉动的影响逐渐加强。该研究结果可为优化过流部件和结构改善离心泵内部流动提供一定参考。In order to reveal the characteristics of unsteady flow field in impeller under cavitation condition of centrifugal pump,the research method combing numerical simulation and experiment was adopted,the steady and unsteady numerical calculations of cavitation flow in impeller were carried out.The results indicate that the numerical calculation fits the external characteristic curve obtained by experiment.The primary area of cavitation is located at the back of the blade near the inlet edge,and the cavitation content is different in each impeller channel during the process of the cavitation.The development of cavitation at balance hole of impeller is delayed,where the growth of cavitation is unique without diffusion and transfer.With the decrease of cavitation number,the area of cavitation concentration is transferred from the area near the rear cover plate to the area near the front cover plate.The development of cavitation has much more influence on pressure on the back of the blade than on the working face.The pressure pulsation spectrum of each monitoring point has typical discrete characteristics,the peak of pressure pulsation occurs at the blade passage frequency fp and its higher harmonic nfp,and pressure pulsation intensity increases continuously along the radial direction.With the decrease of cavitation number,the influence of cavitation on pressure pulsation is gradually strengthened.The research results can provide some references for optimizing the flow parts and improving the internal flow of centrifugal pump.

关 键 词：离心泵 空化流场 空泡 压力脉动 数值分析 

分 类 号：TH3[机械工程—机械制造及自动化] TK311[动力工程及工程热物理—热能工程]