摘要
为研究大型立式轴流泵的空化特性,基于欧拉-欧拉多相流模型中的Mixture混合模型,采用Rayleigh-Plesset空化模型研究5个不同工况下大型立式轴流泵叶片背面空泡演化特征,分析叶片背面空泡面积占比与空化余量的关系,并基于滑移网格技术,利用快速傅里叶变换(fast Fourier transform,FFT)分析设计工况下4种不同空化余量叶片进出口压力脉动规律.结果表明:小流量工况下空泡初生于叶片进口和轮缘侧,呈三角形分布,随着流量增大,空泡沿轮缘侧向叶片出口偏移,大流量工况下初生空泡在压力面进口,随着空化余量降低,空泡均向叶轮出口及轮毂侧扩散;水泵装置效率下降1%时,不同流量下的空泡面积不同,设计工况下空泡面积最大,与设计工况差距越大则空泡面积越小;叶片空泡分布面积比临界值可作为判别大型立式轴流泵临界空化余量的依据,超过临界值后,空泡面积增长减缓,但效率急速下降;叶轮进出口最大压力脉动幅值先上升后下降,其最大幅值与空泡面积临界值对应.
In order to study the cavitation characteristics of large vertical axial flow pumps,based on the Mixture Model in the Euler-Euler multiphase flow model,the Rayleigh-Plesset model is used to study the evolution characteristics of cavitation on the backside of large vertical axial flow pumps under five different operating conditions.The relationship between the void area ratio on the backside of the blades and the cavitation margin is also analyzed.Based on the sliding grid technique,the fast Fourier transform(FFT)is used to analyze the pressure pulsation law of the inlet and outlet blades with four different cavitation allowances under design conditions.The results show that under low flow conditions,cavitation initially occurs at the blade inlet and rim side,with a triangular distribution.As the flow rate increases,the cavitation shifts to the outlet of the blade along the side of the wheel edge.Under the condition of large flow rate,primary cavitation occurs at the pressure surface inlet.As the cavitation margin decreases,cavitation diffuses towards the impeller outlet and hub side.When the efficiency of the pump device decreases by 1%,the cavitation area is different under different flow rates,the design condition is the largest.The larger the gap from the design condition,the smaller the cavitation area is.The critical value of blade cavitation distribution area ratio can be used as the basis for judging the critical cavitation margin of large vertical axial flow pump.After exceeding the critical value,the growth of the void area slows down,but the efficiency decreases rapidly.The maximum pressure pressure pulsation amplitude at the inlet and outlet of the impeller increases first and then decreases,and its maximum value corresponds to the critical value of the cavitation area.The critical value of blade cavitation area ratio can be used as a basis for determining the critical cavitation margin of large vertical axial flow pumps.
作者
李浩
施伟
张烨栋
倪春
鲁健
于贤磊
陈松山
LI Hao;SHI Wei;ZHANG Yedong;NI Chun;LU Jian;YU Xianlei;CHEN Songshan(School of Electrical and Energy Power Engineering,Yangzhou University,Yangzhou 225127,China;Xuzhou Branch of Jiangsu Water Source Co.Ltd of the Eastern Route of the South-to-North Water Diversion Project,Xuzhou 221200,China;Qiantang River Basin Center of Zhejiang,Hangzhou 310020,China)
出处
《扬州大学学报（自然科学版）》
CAS
北大核心
2023年第3期70-78,共9页
Journal of Yangzhou University：Natural Science Edition
基金
国家自然科学基金资助项目(51076136)
江苏省水利科技重点资助项目(2009053)。
关键词
泵站
轴流泵装置
空化特性
数值模拟
pump station
axial flow pump unit
cavitation characteristics
numerical simulation
