灯泡贯流式水轮机全流道压力脉动数值模拟  

Numerical simulation of pressure pulsation in the whole flow passage of bulb turbine

作　　者：钱忠东[1] 魏巍[1] 冯晓波[1] 

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,武汉430072

出　　处：《水力发电学报》2014年第4期242-249,共8页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金资助项目(51079106);教育部新世纪优秀人才支持计划项目(NCET-10-0647)

摘　　要：采用大涡模拟方法对灯泡贯流式水轮机全流道非定常湍流进行数值模拟,分析了额定工况和小流量工况下的压力脉动特征。计算结果表明:额定工况下,导叶前后、转轮出口的压力脉动主频为叶片频率,振幅最大值出现在转轮出口,尾水管内的压力脉动主频为转轮的转动频率,幅值相对较小;小流量工况下转轮出口产生偏心涡带,涡带旋转导致尾水管内产生低频压力脉动,低频压力脉动由尾水管向上游传递,幅值逐渐减小;额定工况下叶片上监测点的压力脉动频率为转轮转动频率的整数倍,幅值较小;小流量工况下,叶片上监测的点压力脉动幅值显著增大,脉动主频与次主频之和约为转轮的转动频率。Large eddy simulation of three-dimensional unsteady turbulent flows in the whole passage of a bulb turbine was conducted, and pressure pulsations in design condition and part-load condition predicted and analyzed. The results show： under design condition, the dominant frequency of pressure pulsations around the guide vanes and at the outlet of runner is equal to the blade frequency and the maximum peak-peak amplitude appears at the outlet of runner; the dominant frequency on the blades is harmonic of runner frequency and the amplitude is relatively small; in the draft tube, the dominant frequency is equal to the runner frequency and the amplitude is also relatively small. Under part-load condition, a vortex rope appears in the draft tube, inducing low frequency pressure pulsations which spread upstream and weaken gradually; the amplitudes of pressure pulsations on the blades are obviously larger than those under design condition and the sum of dominant frequency and second frequency of pressure pulsations on the blades is roughly equal to the runner frequency.

关 键 词：水力机械 贯流式水轮机 压力脉动 数值模拟 

分 类 号：TV136.2[水利工程—水力学及河流动力学]