中文摘要：

对简谐脉动流中加速度为零的极点（如波峰点和波谷点）摩擦压降特性进行了实验和理论研究。实验值与稳态条件下摩擦压降计算值的对比结果表明,相同流速下,脉动流条件下波峰点摩擦压降较稳态计算值略有降低,而波谷点摩擦压降较稳态值增加较多,其幅度随脉动程度的增加（即平均流速和脉动周期降低,脉动速度振幅增加）而增加。针对相同流速下稳态流动、脉动流波峰和波谷点的流动截面速度分布进行计算和分析,结果表明,相同流速下,波谷点流动截面径向速度梯度增加是造成流动阻力增加的原因。

英文摘要：

Friction pressure drop characteristics of the pole points of simple harmonic pulse flow were studied experimentally and theoretically.The comparison between the calculated results through the steady flow friction pressure drop empirical equation showed that the experimental friction pressure drops of crest point are lower than the calculated result,and the cases in trough point are opposite.The difference between the calculated and experimental data increased with the increase of pulse intensity（mean flow rate and pulse amplitude increasing,pulse period decreasing）.The velocity distribution of flow cross section of steady flow,crest and trough points were calculated,and the results showed that the increase of velocity grad along the diameter direction at trough point caused the increase of friction pressure drop.