摘要
用实验方法研究了两端固定输流管道在脉动内流作用下的参数共振问题。所设计的实验系统合理有效,基本符合进行参数共振实验的设计目的。对三种合成管道在几个不同的平均流速和脉动流作用下做了多次重复实验获得了第一振型1/2次谐波参数共振相关实验数据,实验结果与理论结果在定性上一致。本文还对可能引起定量误差的原因做了较详细的分析。通过实验观察,得到以下结论:(1)当平均流速达到一定值时,两端固定管道在一定的脉动流振幅和脉动频率下会产生第一振型1/2次谐波参数共振。脉动流振幅越大,发生参数共振的频率范围也越大。当脉动流振幅小于一定值时,不再发生参数共振。(2)平均流速越大,发生参数共振所需要的脉动流频率就越小。平均流速大小对于能否出现1/2次谐波参数共振、共振区域大小、形状以及位置都有很重要的影响。在其它条件一定的情况下,低频脉动时平均流速越大管道越容易失稳。以上观察到的现象与理论分析中得到的结果是一致的。
The parametric resonances of first mode of order 1/2 of clamped-clamped pipes conveying pulsating fluid are investigated under some different mean flow velocities. Unstable regions of pipes are obtained experimentally, and are compared with those obtained by theoretical analysis. The experimental results are in good agreement with the theoretical results qualitatively. The following phenomena are found from the experiments: 1. For a given mean flow velocity, the first mode parametric resonance may occur under some values of amplitude and frequency of pulsating fluid. When the amplitude of the pulsating fluid is less than a certain value, the resonance will not occur again;2. When the mean velocity of flow is decreased, the region of the parametric resonance moves towards left side. This implies that as the mean flow velocity decreases the parametric resonance may take place more easily with relatively lower frequency of pulsating flow.
出处
《振动与冲击》
EI
CSCD
北大核心
2007年第11期169-173,177,共6页
Journal of Vibration and Shock
基金
国家自然科学基金(10372063)
航空科学基金(04B54001)资助项目
关键词
参数共振
实验
脉动流
输流管道
parametric resonance, experiment, pulsating fluid, pipes conveying fluid
