喷嘴释放单气泡的声发射特性

发布时间：2018-03-14 18:18

本文选题：气液两相流　切入点：气泡　出处：《化工学报》2017年05期 　论文类型：期刊论文

【摘要】：利用声发射技术在单气泡发生实验装置中研究了气液两相流中单气泡的动力学特性,使用自行开发的采集处理程序进行气泡声信号的参数提取,采用统计分析、小波变换和快速傅里叶变换对声信号进行时域和频域范围的分析。分析结果表明,声发射技术可以检测到管内气泡的声信号,具有较高的信噪比,且声信号随着喷嘴尺寸的增大而增大,随着液相表面张力的减小而减小。比较不同喷嘴直径下气泡的频率谱,发现喷嘴释放气泡发出的声信号频率为150~200 k Hz,且随着喷嘴直径的增大,峰值频率相应增大,提出了声信号峰值频率与气泡尺寸之间的关联式。同时得到了气泡上升过程中的连续形态变化,分析了气泡产生声音的机理。研究表明,声发射技术是一种灵敏度高、测量手段方便的方法,可用于气液两相流气泡运动特性的检测。
[Abstract]:Using acoustic emission technique to study the dynamic characteristics of the single bubble in the gas-liquid two-phase flow in single bubble occurred in the experimental device, using the extracted parameters acquisition and processing procedures developed for bubble sound signal, by means of statistical analysis, wavelet transform and fast Fourier transform analysis of time domain and frequency domain of the acoustic signal. The analysis results show that the the acoustic emission technique to acoustic signal tube bubble detection, has a high signal-to-noise ratio, and the acoustic signal with increasing nozzle size increases, decreases with decreasing surface tension of liquid phase. Comparison of different nozzle diameter bubble frequency spectrum, and frequency of acoustic signal emitted by the nozzle release bubbles is 150~200 K Hz, and with the increasing of nozzle diameter, the peak frequency increases accordingly, put forward the relationship between the peak frequency of the acoustic signal and the bubble size. At the same time the bubble rising in the process of The mechanism of bubbles producing sound is analyzed. The research shows that acoustic emission technology is a high sensitivity and convenient measurement method, and it can be used to detect bubble movement characteristics in gas-liquid two-phase flow.

【作者单位】：中国石油大学(华东)储运系山东省油气储运安全省级重点实验室;
【基金】：国家自然科学基金项目(51376197)~~
【分类号】：TQ021.1

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