中文摘要：

为研究S形轴伸贯流泵装置时变湍流场内部压力脉动规律，应用CFD技术对S形轴伸贯流泵装置流道内部流动开展了三维非定常数值模拟，并将泵装置性能预测结果与模型试验结果进行了对比。获取了3种特征工况（小流量工况KQ=0．368，高效工况KQ=0．460，大流量工况KQ=0．552）时泵装置流道内部关键位置处21个监测点的压力脉动信息，并对其进行了时域和频谱分析。结果表明：进水流道出口处水流的脉动以叶片通过的频率为主，压力脉动幅值从流道壁面侧向轮毂侧逐渐减小。流量系数KQ从0．368增至O．552时，进水流道出口各监测点的脉动幅值随之减小。出水流道弯管段进口的平均压力系数幅值与流道中部的平均压力系数幅值相差不大，最大差值仅为0．0005，水流诱发的出水流道内部压力脉动较小。受导叶体出口环量的影响，相同流量系数时出水流道内各监测点的脉动主频差异较大，不同流量系数时相同测点的脉动主频也略有差异。

英文摘要：

Numerical simulations of three-dimensional unsteady flows were carried out to investigate pressure fluctuations in the passages of a tubular pump system with S-shaped shaft extension in different operating conditions by using the code CFX and comparing with experiments on scale model. Pressure fluctuations at 21 locations of measurement in inlet and outlet passages were obtained and analyzed in time and frequency domains for three typical working conditions of different flow rates. At the exit of inlet passage, the pressure fluctuations show a frequency dominated by the rotation speed of impeller and the blade numbers, and their amplitudes decrease gradually from wall to hub. And these amplitudes decrease with flow coefficient in the range from 0.368 to 0.552. The amplitude of average pressure coefficient at the inlet of elbow tube that is one part of outlet passage, is very close to that in middle part of outlet passage, with a difference less than 0.0005. The fluctuating amplitudes in outlet passage are smaller than those at the exit of inlet passage. Under influence of the circulation at guide vane outlet, the dominant frequencies at different locations of measurements in a fixed working condition vary in a great extent, and those at a fixed location vary slightly with flow rate.