摘要
为了研究低比转速轴流式水轮机压力脉动问题,对某低比转速轴流式水轮机进行了模型试验.采集了蜗壳、无叶区和尾水锥管等5个测点的压力脉动试验数据,采用叶片出口速度头的压力脉动相对幅值预测原型机的压力脉动性能;基于FFT频谱分析,研究测点位置的压力脉动频率成分.研究结果表明:蜗壳和无叶区的脉动幅值随着出力的增加有减小的趋势,尾水锥管的压力脉动幅值随着出力的增加有增大的趋势;尾水管中的低频成分为涡带的旋转频率,该频率成分的压力脉动向上游传递至蜗壳入口;转频和叶频等频率成分的出现表明整个流道中均受到动静干涉的影响.
In order to research the pressure fluctuation, model test was carried out on a low specific speed Kaplan turbine. The test data of 5 survey points were collected on casing, vaneless space and draft tube cone. Dimensionless pressure fluctuation amplitude relative to the velocity head at the runner blade outlet was used to predict the pressure fluctuation amplitude of prototype and the frequency of survey points were gained based on FFT transform. The results indicate that the pressure fluctuation amplitude of casing and vaneless area has a downward trend with the increase of output. However,the pressure fluctuation amplitude of draft tube cone has a opposite trend with the increase of output. It is the rotation frequency of the vortex that low frequency in the draft tube and it passed to the volute en- trance. The high-frequency components of rotating frequency and double frequency were existed showed that the whole flow passage should be affected by rotor- stator interaction.
出处
《排灌机械工程学报》
EI
CSCD
北大核心
2017年第10期869-873,911,共6页
Journal of Drainage and Irrigation Machinery Engineering
