离心泵内部空化流动的数值预测  

Numerical prediction of cavitation flow in centrifugal pump

作　　者：刘宜[1] 张文军[2] 杜杰 

机构地区：[1]兰州理工大学流体动力与控制学院,甘肃兰州730050 [2]四川建筑职业技术学院,四川德阳618000 [3]浙江水泵总厂有限公司,浙江临海317000

出　　处：《排灌机械》2008年第3期19-21,29,共4页Drainage and Irrigation Machinery

基　　金：甘肃省自然科学基金(ZS022-A25-018)

摘　　要：为了研究离心泵内的空化流动,将完整空化模型和混合流体两相流模型相结合,对比转速为95的离心泵叶轮在设计工况下的空化流动进行数值模拟.介绍了空化流动的模拟方法,通过计算获得了叶片表面压力分布,并得出了该离心泵的有效空化余量-扬程落差特性曲线,有效地预测了流道内空蚀发生的部位和发展情况.结果证明,叶轮内空化区域的增长使离心泵的扬程下降,影响到泵的运转特性;当泵内发生少量空泡时,不会影响到外特性的变化,而当空泡大量发生时,会堵塞流道,使液流连续性破坏,性能下降,这与理论结果基本吻合,计算值与规定值的误差在5%以内.数值模拟计算方法较好地模拟了离心泵内的空化两相流的静态特征.In order to study the cavitation flow in a centrifugal pump, numerical simulation of steady cavitating turbulent flow in a specific speed 95 centrifugal pump was carried out by using a full cavitation model and a mixing two-phase flow model. The distribution of static pressure on the blade surfaces and the pump＇s available NPSH performance curve were obtained, and the region and the degree of cavitation in the flow passage are respectively predicted. The results show that with increasing cavitation area, the head of centrifugal pump declines. By theoretical analysis, small cavitation bubbles will not affect the operating characteristics of pumps, but a large number of cavitation bubbles will block the flow, and destroy the flow continuity and the performance. It is found that the simulation error is less than 5% compared with the experiment results.

关 键 词：离心泵 叶轮 空化 流场 数值预测 

分 类 号：TH311[机械工程—机械制造及自动化]