Abstract: Acoustic emission (AE) as a technology of non-destructive detection for measuring the gas-liquid two-phase flow is superior to traditional method in non-invasiveness, no destruction of test pipe and flow field distribution, strong signal, and high sensitivity. The experiment was operated on a multiphase flow experimental device in Hebei University. Experiments based on the data processing method collected the features of gas-liquid two-phase flow in vertical pipe. The acoustic emission technology could reflect the dynamic characteristics of the typical flow patterns: bubbly flow, slug flow, annular flow, and the transition state of emulsified foam had some obviously differences in the time domain and frequency domain signals. There was a big difference between the values of Shannon entropy of wavelet energy and wavelet packet decomposition. The state of two-phase flow in vertical pipe was verified, and four typical flow patterns were accurately identified with pattern recognition. The acoustic emission technology is likely to be a new method for detection of gas-liquid two-phase flow.

Key words: acoustic emission, multiphase flow, Shannon entropy, flow pattern identification, measurement

摘要： 声发射（AE）作为一种无损检测手段，用于气液两相流的测量具有非侵入式、测量不破坏被测管道及流场分布，信号强、灵敏度高等优点。利用声发射技术在河北大学垂直管气液两相流管道上进行了大量实验，运用现代信息数据处理方法对气液两相流垂直管道流型特征参数进行了提取。分析结果表明利用声发射手段提取出的流型特征参数可以反映出典型流型下的动力学特征。垂直管道中，泡状流、弹状流、环状流以及过渡状态下的乳沫状流在时域和频域信号中有着明显区别，小波能量和小波包分解后的信息熵的值也存在较大的差异性，从另一角度验证了在不同流型下两相流体在管道内部不同的运动状态，利用模式识别的思想，对垂直管4种典型流型进行了流型识别，取得了较好的效果，研究结果表明声发射技术可以作为一种技术手段用于气液两相流流动的检测。

关键词: 声发射, 多相流, 信息熵, 流型识别, 测量