低比转速混流式水轮机流动噪声数值模拟  

Numerical Simulation of Flow Noise in Francis turbine with Low Specific Speed

作　　者：王惠芝[1] 周大庆[1] 张蓝国[1] 

机构地区：[1]河海大学能源与电气学院,江苏南京211100

出　　处：《水电能源科学》2014年第8期153-156,共4页Water Resources and Power

基　　金：国家自然科学基金项目(51106042)

摘　　要：为预测低比转速混流式水轮机的主要流动噪声,采用重整化群RNGκ-ε模型和FW-H模型,计算了不同导叶与转轮叶片径向间距时水轮机导叶与转轮壁面上压力脉动构成的偶极子声源产生的流动噪声,分析了导叶与转轮叶片径向间距对水轮机压力脉动及噪声特性的影响,以及压力脉动与流动噪声之间的关系。结果表明,导叶末端和转轮叶片进口背面压力脉动最剧烈,是主要的偶极子噪声源,压力脉动和流动噪声的离散噪声在叶频及其谐频处出现峰值;随导叶与转轮叶片径向间距增大,压力脉动幅值减小,流动噪声减小,因此适当增大水轮机导叶与转轮叶片径向间距是一种有效降低流动噪声的途径。RNG κ-ε model and FW-H model were adopted to predict the flow noise in Francis turbine with low specific speed. The flow noise caused by dipole source from pressure fluctuation on the wall of guide vane and runner with different radial spacing was calculated. And then the influence on the turbine pressure fluctuation and noise feature made by radial spacing between guide vane and blade in runner, and the relationship between the pressure fluctuation and flow noise were analyzed. The results show that the end of the guide vane and the back of the blade inlet are main dipole noise source, where have the most severe pressure fluctuation; the pressure fluctuation and discrete noise in flow noise has obvious peak value at the blade passing frequency and harmonic frequency; with the increasing of radial spacing between guide vane and blade in runner, pressure fluctuation amplitude decreases and the flow noise reduces. Therefore, appropriately increasing radial spacing between guide vane and blade in runner is an effective way to reduce flow noise.

关 键 词：低比转速 混流式水轮机 流动噪声 数值模拟 

分 类 号：TK733.1[交通运输工程—轮机工程] TH312[动力工程及工程热物理—流体机械及工程]