空化对离心泵低频水力振动影响的数值研究  

Numerical study on effects of cavitations for centrifugal pump low frequency hydraulic vibration

作　　者：陈喜阳[1] 郭庆[1] 孙建平[1] 张克危[1] 

机构地区：[1]华中科技大学能源与动力工程学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2014年第6期6-11,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：中央高校基本科研业务费专项资金资助项目(0118120034);华中科技大学自主创新研究基金资助项目(0118120050)

摘　　要：选择k-ε湍流模型和空泡动力学理论对离心泵内部的空化流场进行计算,获得了三种不同空化阶段(无空化、空化初生及空化充分发展)叶轮内部气泡分布规律,捕捉了叶轮受力以及蜗壳壁面和叶轮出口压力脉动的动态信息.时频分析结果显示:数值仿真场中压力和受力在空化不同阶段表现出不同的时频特性;随着进口压力的降低,气泡首先在叶片背部产生并逐渐随水流扩展;在不同空化阶段,蜗壳内压力脉动主频均为叶频,蜗舌处压力脉动幅值最大;当远离蜗舌时,叶片作用大于动静干涉,叶轮出口出现了比蜗壳壁面更多的高频成分;叶轮Y向动态受力峰峰值变化幅度明显大于X和Z向,空化的发展主要引起叶轮Y向振动加剧.The unsteady cavitating flow in centrifugal pump was simulated by k-εturbulence model and bubble dynamics theory.The bubble distribution rules in the impeller were obtained under three different cavitation developing stages（non-cavitation,cavitation inception,and fully developed cavitation）.Also,dynamic information of the forces on impeller and the pressure pulsations both on the wall of volute and outlet of impeller were captured.The results of time-frequency analysis show that the pressure and stress appear diverse time-frequency characteristics at the different cavitation developing stages.Along with the decreasing of pressure in the inlet,bubbles first appear on the suction side of blade first and gradually expand along the direction of flow.During the different stages of cavitation,the first frequency of pressure pulsation in volute is blade pass frequency and the amplitude near the volute tongue is the greatest,since the effect of rotor-stator interaction is greater than by blade,and the high frequency components are more presented on outlet of impeller than on the wall of volute along with away from the volute tongue.With the development of cavitation,the peak-peak value change of Y direction impeller force is more obvious than X direction and Zdirection impeller force,and the more Ydirection impeller force,the more cavitation develops.

关 键 词：离心泵 空化 数值模拟 振动 压力脉动 监测 

分 类 号：TH311[机械工程—机械制造及自动化]