水下自激吸气式射流装置冲击力时频特性分析

发布时间：2018-01-21 22:34

本文关键词： 水下自激吸气射流冲击力时频特性　出处：《振动与冲击》2016年24期 　论文类型：期刊论文

【摘要】：利用水下射流循环试验系统对水下自激吸气式射流装置进行了冲击试验,得到了装置吸气和不吸气条件下冲击力时域波形,运用第二代小波变换和Wigner-Ville分布相结合的方法提取了冲击力时频特性,研究了装置吸气和不吸气条件以及不同围压和靶距下冲击力频带能量分布规律。结果表明,存在最优下喷嘴直径使装置的冲击力时域特征参数最佳;装置冲击力能量主要集中在低频带,且围压、靶距和吸气对频带能量比影响较大;吸气对装置冲击力频率成分、能量密度分布和脉冲效果均有明显影响,而围压和靶距只对能量密度分布和脉冲效果影响较大;碰撞体测点压力反映了装置聚能和释能的状态且与冲击力能量密度分布存在着对应关系。
[Abstract]:In this paper, the impact test of underwater self-inspiratory jet device is carried out by using the underwater jet cycle test system, and the time-domain waveform of the impact force is obtained under the condition of suction and non-suction of the device. The time-frequency characteristic of impact force is extracted by combining the second generation wavelet transform with Wigner-Ville distribution. The conditions of suction and non-suction of the device and the energy distribution of the impact force band under different confining pressure and target distance are studied. The results show that the existence of the optimum nozzle diameter makes the time domain characteristic parameters of the impact force the best. The impact energy of the device is mainly concentrated in the low frequency band, and the confining pressure, the target distance and the inspiratory energy ratio have great influence on the frequency band energy ratio. Inspiratory has obvious influence on the frequency component, energy density distribution and pulse effect of the device, while confining pressure and target distance only have great influence on the energy density distribution and pulse effect. The pressure at the point of impact body reflects the state of the device's accumulated energy and energy release and has a corresponding relationship with the energy density distribution of the impact force.
【作者单位】：华北水利水电大学电力学院;
【基金】：国家自然科学基金项目(51309099)
【分类号】：O358
【正文快照】： 研究表明水射流引入气体可以明显改善其冲击性能[1-4]。水下自激吸气式射流装置是在自激脉冲射流和气液射流研究基础上提出的一种新型射流装置,它通过在装置腔体上布置吸气孔,利用一定的工作压力可以使装置自吸气,气体在腔内与水充分混合后,在下喷嘴出口形成水气射流,在前期工

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