Signals features extraction in liquid-gas flow measurements using gamma densitometry. Part 1: time domain
Signals features extraction in liquid-gas flow measurements using gamma densitometry. Part 1: time domain
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使用伽玛密度计提取液-气流量测量中的信号特征。
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
P. Hanus
中科院分区：
文献类型：
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作者：
R. Hanus;M. Zych;L. Petryka;M. Jaszczur;P. Hanus
了解流程的结构对于正确执行许多工业流程确实非常重要。在这种情况下，可以通过使用时间序列分析来描述两相流状态，例如在频域中。在本文中，基于傅里叶变换（FT）和短时傅里叶变换（STFT）的经典光谱分析被应用于利用伽马射线吸收来分析水-空气流获得的信号。该方法通过在实验室液压装置上进行的实验中收集的数据进行说明，该装置具有长度为 4.5 m、内径为 30 mm 的水平管道，配备有两个 241Am 放射源和带有 NaI(Tl) 晶体的闪烁探针。这项工作考虑了从塞子、气泡和过渡塞子-气泡流探测器获得的随机信号。对记录的原始信号进行分析，并使用自谱密度函数 (ADF)、互谱密度函数 (CSDF) 和 STFT 频谱图提取频域中的多个特征。详细分析的结果发现，最有希望识别的流结构是：CSDF幅度的最大值、所选频率范围内的CSDF幅度之和、以及STFT频谱图所选幅度之和的最大值。
Knowledge of the structure of a flow is really significant for the proper conduct a number of industrial processes. In this case a description of a two-phase flow regimes is possible by use of the time-series analysis e.g. in frequency domain. In this article the classical spectral analysis based on Fourier Transform (FT) and Short-Time Fourier Transform (STFT) were applied for analysis of signals obtained for water-air flow using gamma ray absorption. The presented method was illustrated by use data collected in experiments carried out on the laboratory hydraulic installation with a horizontal pipe of 4.5 m length and inner diameter of 30 mm equipped with two 241Am radioactive sources and scintillation probes with NaI(Tl) crystals. Stochastic signals obtained from detectors for plug, bubble, and transitional plug – bubble flows were considered in this work. The recorded raw signals were analyzed and several features in the frequency domain were extracted using autospectral density function (ADF), cross-spectral density function (CSDF), and the STFT spectrogram. In result of a detail analysis it was found that the most promising to recognize of the flow structure are: maximum value of the CSDF magnitude, sum of the CSDF magnitudes in the selected frequency range, and the maximum value of the sum of selected amplitudes of STFT spectrogram.