自振射流频率特性的试验研究
发布时间：2019-06-21 09:14
【摘要】：淹没条件下自振射流的频率特性决定着射流的打击效果,而获取射流的压力脉动信号对研究自振射流频率特性至关重要。射流的压力信号通常借助于冲蚀试验和标靶打击试验来间接获得,这里采用喷嘴腔内压力信号提取方法对自振射流频率特性进行试验研究。通过比对分析证明,直接采集腔内压力信号可以有效获取自振射流的频谱特征。与标靶打击试验相比,该方法受随机扰动少,频谱清晰,更有利于自振射流特征频率的提取。在此基础上,通过频谱分析得到自振射流的共振频率,并研究来流参数对自振射流频率特性的影响。试验结果显示,自振射流的共振频率并非是对来流扰动频率的直接放大,且受来流扰动的影响很小。来流速度对自振射流共振频率的影响较大,随着来流速度的增加,自振射流的共振频率及其对应的幅值均显著增加。这表明适当加大来流速度可以有效地改善自振射流的振荡特性。
[Abstract]:The frequency characteristic of the self-oscillating jet in the submerged condition determines the striking effect of the jet, and the pressure pulse signal of the obtained jet is of great importance to the frequency characteristic of the natural gas jet. The pressure signal of the jet is obtained indirectly by means of the erosion test and the target striking test, and the frequency characteristics of the self-vibration jet are studied by using the pressure signal extraction method in the nozzle cavity. By comparison with the analysis, the frequency spectrum of the self-vibration jet can be obtained by directly collecting the pressure signal in the cavity. Compared with the target-striking test, the method has less random disturbance and clear spectrum, and is more beneficial to the extraction of the characteristic frequency of the natural-vibration jet. On this basis, the resonance frequency of the natural-vibration jet is obtained by the spectrum analysis, and the influence of the flow parameters on the frequency characteristics of the natural-vibration jet is studied. The experimental results show that the resonant frequency of the free-vibration jet is not the direct amplification of the flow disturbance frequency, and the influence of the current disturbance is very small. The influence of the flow velocity on the resonant frequency of the self-vibration jet is large, and with the increase of the flow velocity, the resonant frequency of the self-vibration jet and its corresponding amplitude are obviously increased. This indicates that the oscillation characteristics of the self-oscillating jet can be effectively improved by increasing the flow velocity.
【作者单位】： 北京科技大学机械工程学院;
【基金】：国家自然科学基金资助项目(51274021)
【分类号】：O358
本文编号：2503961
[Abstract]:The frequency characteristic of the self-oscillating jet in the submerged condition determines the striking effect of the jet, and the pressure pulse signal of the obtained jet is of great importance to the frequency characteristic of the natural gas jet. The pressure signal of the jet is obtained indirectly by means of the erosion test and the target striking test, and the frequency characteristics of the self-vibration jet are studied by using the pressure signal extraction method in the nozzle cavity. By comparison with the analysis, the frequency spectrum of the self-vibration jet can be obtained by directly collecting the pressure signal in the cavity. Compared with the target-striking test, the method has less random disturbance and clear spectrum, and is more beneficial to the extraction of the characteristic frequency of the natural-vibration jet. On this basis, the resonance frequency of the natural-vibration jet is obtained by the spectrum analysis, and the influence of the flow parameters on the frequency characteristics of the natural-vibration jet is studied. The experimental results show that the resonant frequency of the free-vibration jet is not the direct amplification of the flow disturbance frequency, and the influence of the current disturbance is very small. The influence of the flow velocity on the resonant frequency of the self-vibration jet is large, and with the increase of the flow velocity, the resonant frequency of the self-vibration jet and its corresponding amplitude are obviously increased. This indicates that the oscillation characteristics of the self-oscillating jet can be effectively improved by increasing the flow velocity.
【作者单位】： 北京科技大学机械工程学院;
【基金】：国家自然科学基金资助项目(51274021)
【分类号】：O358
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1 杨叔子;多自由度线性阻尼系统频率特性的研究——兼论机床动态性能分析中的一些问题[J];华中工学院学报;1981年04期
，本文编号：2503961
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