Multi-Scale Morphological Analysis of Conductance Signals in Vertical Upward Gas–Liquid Two-Phase Flow

Lian, Enyang; Ren, Yi; Han, Ye; Liu, Weixin; Jin, Ningde; Jing, Zhao

doi:10.1515/zna-2016-0235

Cited by 9 publications

(6 citation statements)

References 33 publications

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“…Although the mechanisms are different, both theories are important in describing and understanding the chromatographic phenomenon [15]. The injection of small volumes of chemical species into a pipe with transport media such as gases [5,16], liquids [15] or mixtures of gases and liquids [17] produces peaks of similar shapes, as observed by appropriate detection units [18]. Chromatographic peaks even resemble those of flow through pipes without chromatographic columns where injected volumes do not undergo separations [19,20].…”

Section: Introductionmentioning

confidence: 99%

Signal convolution indicates chromatographic pulse flow and open-end flow

2019

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Only slices are measured of very long segments of solute molecules that are injected into columns in chromatographic systems. Since the concentration of solute molecules changes during elution as a function of time, the observed signal should be reconstructed for a comparison of experimental results with theory. The influence of response time on the observed signal in high-performance liquid chromatography experiments was investigated in detail using a C-18 column for the measurement of caffeine in pure methanol as eluent. The response function influenced the observed signal by converting the square signal of pulse flow into a chromatographic peak. At faster linear flow rates (LFRs), the response function influenced the observed shape of the chromatographic peak, whereas diffusion dominated at slow LFRs. By convolution of the square signal with the response function, it was possible to predict the shape of the observed signal and chromatographic parameters and to provide an alternative explanation to the van Deemter equation. By using the shape of a known response function and modelling the new theory to data, it was proposed that the injected solute molecules were eluted over long distances through the chromatographic column, distances that are much longer than the physical length of the system.

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Section: Introductionmentioning

confidence: 99%

Signal convolution indicates chromatographic pulse flow and open-end flow

2019

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“…The complex multiscale character of flows was claimed by Fan et al [12,13] who also used the data of light transmission through a minichannel. In this context, the multiscale morphological analysis was proposed by Lian et al [14]. The authors of ref [14].…”

Section: Introductionmentioning

confidence: 99%

Classification of two-phase flow patterns using multifractal analysis of pressure oscillations

Mosdorf

Litak

Górski

et al. 2021

Forsch Ingenieurwes

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The two-phase flow patterns (air–water) in horizontal square minichannel (3 × 3 mm) has been analysed. The multifractal analysis of pressure drop fluctuations was used for qualitative assessment of two-phase flow patterns. The results of the complexity analysis using the multifractal spectral width (Δh) are presented. The proposed method allows us to identify the following two-phase flow patterns: micro-bubbles flow, micro- and minibubbles flow, micro- and mini-bubbles with confined bubbles flow, slug flow, stratified flow. The obtained results confirm that this type of analysis can be considered as an alternative way of identification of two-phase flow patterns in the minichannel. The work also focuses on the discussion of the occurrence and identification of bubbles churns in slugs and churns.

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“…Multiscale character of flows were raised by Fan et al (2013Fan et al ( , 2015, who also used the data of light transmission through a minichannel. Finally, the complex multiscale morphological analysis using electric conductance signals was proposed by Lian et al (2016).…”

Section: Introductionmentioning

confidence: 99%

Periodic Trends in Two-Phase Flow Through a Vertical Minichannel: Wavelet and Multiscale Entropy Analyses Based on Digital Camera Data

Górski

Litak

Mosdorf

et al. 2019

Acta Mechanica Et Automatica

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By changing the air and water flow relative rates in the two-phase (air-water) flow through a minichannel, we observe aggregation and partitioning of air bubbles and slugs of different sizes. An air bubble arrangement, which show non-periodic and periodic patterns. The spatiotemporal behaviour was recorded by a digital camera. Multiscale entropy analysis is a method of measuring the time series complexity. The main aim of the paper was testing the possibility of implementation of multiscale entropy for two-phase flow patterns classification. For better understanding, the dynamics of the two-phase flow patterns inside the minichannel histograms and wavelet methods were also used. In particular, we found a clear distinction between bubbles and slugs formations in terms of multiscale entropy. On the other hand, the intermediate region was effected by appearance of both forms in non-periodic and periodic sequences. The preliminary results were confirmed by using histograms and wavelets.

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Multi-Scale Morphological Analysis of Conductance Signals in Vertical Upward Gas–Liquid Two-Phase Flow

Cited by 9 publications

References 33 publications

Signal convolution indicates chromatographic pulse flow and open-end flow

Signal convolution indicates chromatographic pulse flow and open-end flow

Classification of two-phase flow patterns using multifractal analysis of pressure oscillations

Periodic Trends in Two-Phase Flow Through a Vertical Minichannel: Wavelet and Multiscale Entropy Analyses Based on Digital Camera Data

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