原型混流式水轮机压力脉动特性CFD模拟分析  

Pressure pulsations of a prototype Francis turbine analyzed by CFD

作　　者：尤建锋 程永光[1] 付亮[2] 夏林生 蒋勇其 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]湖南省电力科学研究院,湖南长沙410007

出　　处：《武汉大学学报（工学版）》2016年第4期509-515,520,共8页Engineering Journal of Wuhan University

基　　金：国家自然科学基金项目(编号:51039005;51579187)

摘　　要：水轮机压力脉动与流动特性紧密关联.在保证CFD模拟与原型试验结果吻合的基础上,对覆盖某原型水轮机运行区间的25个稳态工况进行了模拟,分析了压力脉动特性及流态特性的对应关系.结果表明,该水轮机存在不稳定的运行开度区间,区间大小和位置随水头而变动;转轮内存在叶道涡,尾水管内存在碎涡及螺旋涡带,碎涡相互干扰使得尾水管低频脉动丰富,螺旋涡带撞击尾水管壁面产生低频高幅脉动并向上游直线传播;动静干涉产生的高频高幅脉动幅值并非随导叶开度增加而成线性增大.该结论可为机组运行和振动特性研究奠定基础.The pressure pulsations in a water turbine are strongly related to the flow characteristics.Based on the consistence between the computational fluid dynamics（CFD）simulation and prototype test,25 steady conditions that can cover the whole operating range are simulated and the correlation analysis between the pressure pulsations and flow patterns is conducted.The results show that the turbine operates unstably with a certain range of the guide vane opening,which varies according to the head.The channel vortex appears in the runner;and the broken vortex and helical vortex rope appears in the draft tube.The interaction between broken vortex enriches the low-frequency pulsations in the draft tube.The helical vortex rope leads to low-frequency and high-amplitude pulsations when striking on the wall of the draft tube and these pulsations spread to the upstream in a straight line process.Besides,the amplitudes of high-frequency pressure caused by the rotor-stator interaction have no direct proportion relationship with the guide vane openings.These results can lay the foundation for the unit operating and for the researches of the vibration characteristics.

关 键 词：原型水轮机 压力脉动 尾水管涡带 CFD模拟 

分 类 号：TV734.1[水利工程—水利水电工程]