侧壁式压水室离心泵空化特征数值计算  

Numerical Simulation on Cavitation Flow in a Centrifugal Pump with Slope Volute

作　　者：张宁[1] 杨敏官[1] 高波[1] 李忠[1] 陆胜[1] 

机构地区：[1]江苏大学能源与动力工程学院,镇江212013

出　　处：《工程热物理学报》2015年第1期71-74,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51206063)

摘　　要：基于CFD方法,采用混合两相模型、标准κ-ε方程和sighal发展的全空化模型,对具有特殊结构形式的侧壁式压水室离心泵空化特征进行数值计算。预测了泵在未发生空化和空化条件下的能量性能,并且分析了设计流量下叶片表面和流道内的空泡分布情况。结果表明:在大流量工况下,泵的必需汽蚀余量大,容易产生空化现象。随着泵进口压力的降低,空泡最先出现在泵叶片背面靠近进口边附近;当进口压力进一步降低时,空泡区域开始快速增加,向叶片出口延伸,泵的扬程开始大幅下降。进口压力继续降低时,叶片工作面开始出现空泡,叶轮周向流道内开始充满空泡,此时泵的扬程急剧下降,泵的稳定运行工况被破坏。不同汽蚀余量下,叶频处压力幅值变化明显,在临界汽蚀点处几乎达到极小值。Full cavitation model、 mixture and standard κ-ε model were used to investigate cavitation flow in a centrifugal pump with slope volute.Performance of model pump at cavitation and non-cavitation conditions were obtained,and cavitation bubbles distribution in blade surface and impeller channels were discussed.The results show that:at high flow rate,cavitation easily occurs in model pump.When static pressure at pump inlet decreases,cavitation bubbles firstly appear in suction pressure side of blade inlet.With pressure reducing further,cavitation region expands to impeller outlet,and head of model pump is affected obviously.Then cavitation regions transform to blade pressure side,and the whole impeller channels are filled with cavitation bubbles leading to pump performance dropping rapidly.At full cavitation condition,steady operating status of model pump is destroyed.Under different NPSH working conditions,pressure amplitude at blade passing frequency differs,and pressure amplitude almost reaches minimum value at critical NPSH.

关 键 词：离心泵 侧壁式压水室 数值计算 空化 

分 类 号：TH311[机械工程—机械制造及自动化]