轮缘间隙对轴流泵内压力脉动的影响.doc


轮缘间隙对轴流泵内压力脉动的影响#
黎耀军1,沈金峰1,丁向华1,唐学林1,张志民2*
(1. 中国农业大学水利与土木工程学院,北京 100083;
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2. 中国水利水电科学研究院,北京 100044)
摘要:针对轴流泵轮缘间隙泄漏湍流的典型非定常特征及其对泵外特性的影响,采用基于
S-A 模型的 DES 方法和滑移网格技术,对轴流泵在设计工况下的内部湍流进行了数值计算,
重点分析了 4 组轮缘间隙下泵内非定常流场特性及压力脉动特性。在设计轮缘间隙下,预测
的泵扬程和效率与试验数据基本吻合,最大相对误差分别为 %和 %。计算结果表明:
随轮缘间隙增大,水泵扬程和效率均呈下降趋势;轮缘泄漏涡强度和影响范围随轮缘间隙增
加而增大,当轮缘间隙为 ‰D2 时,轮缘泄漏涡扩散至相邻叶片出口边;不同轮缘间隙下,
叶轮区压力脉动频率均以叶片通过频率为主;靠近叶片进口的叶轮室内壁压力脉动幅值随轮
缘间隙的增大呈下降趋势,叶轮室中部压力脉动随轮缘间隙增大而增加;叶轮出口断面的压
力脉动频域特性在不同轮缘间隙下均以 1 倍叶片通过频率为主,脉动幅值随轮缘间隙增加而
减小。
关键词:轴流泵;轮缘间隙;DES 方法;泄漏涡;压力脉动
中图分类号:TH312
Effect of Tip Clearance on the Pressure Fluctuation in
Axial-flow Pump
LI Yaojun1, SHEN Jinfeng1, DING Xianghua1, TANG Xuelin1, ZHANG Zhimin2
(1. College of Water Resources & Civil Engineering, China Agricultural University, Beijing
100083;
2. China Institute of Water Resources and Hydropower Research,Beijing 100044)
Abstract: Three-dimensional unsteady numerical simulations were carried out to analyze the
influence of the tip clearance on the unsteady flow and performance of the axial-flow pump at
design condition. The Spalart-Allmaras model based Detached Eddy Simulation method with
sliding mesh technique has been used for the current study. Four different tip clearance sizes were
considered, and the internal unsteady flow and its pressure pulsations were simulated in detail.
The predicte