scholarly journals Multi-scale recurrence quantification analysis of the dynamic characteristics of two phase flow pattern

2008 ◽  
Vol 57 (10) ◽  
pp. 6145
Author(s):  
Dong Fang ◽  
Jin Ning-De ◽  
Zong Yan-Bo ◽  
Wang Zhen-Ya
Keyword(s):  
Flow Pattern ◽  
Dynamic Characteristics ◽  
Two Phase Flow ◽  
Recurrence Quantification Analysis ◽  
Phase Flow ◽  
Two Phase ◽  
Multi Scale ◽  
Recurrence Quantification ◽  
Quantification Analysis

scholarly journals Detection of Two-Phase Flow Patterns in a Vertical Minichannel Using the Recurrence Quantification Analysis

2015 ◽  
Vol 9 (2) ◽  
pp. 99-104
Author(s):  
Romuald Mosdorf ◽  
Grzegorz Górski
Keyword(s):  
Time Series ◽  
Two Phase Flow ◽  
Bubbly Flow ◽  
Flow Patterns ◽  
Recurrence Quantification Analysis ◽  
Phase Flow ◽  
Two Phase ◽  
Signal Characteristics ◽  
Recurrence Quantification ◽  
Quantification Analysis

Abstract The two-phase flow (water-air) occurring in square minichannel (3x3 mm) has been analysed. In the minichannel it has been observed: bubbly flow, flow of confined bubbles, flow of elongated bubbles, slug flow and semi-annular flow. The time series recorded by laser-phototransistor sensor was analysed using the recurrence quantification analysis. The two coefficients:Recurrence rate (RR) and Determinism (DET) have been used for identification of differences between the dynamics of two-phase flow patterns. The algorithm which has been used normalizes the analysed time series before calculating the recurrence plots.Therefore in analysis the quantitative signal characteristicswas neglected. Despite of the neglect of quantitative signal characteristics the analysis of its dynamics (chart of DET vs. RR) allows to identify the two-phase flow patterns. This confirms that this type of analysis can be used to identify the two-phase flow patterns in minichannels.

Measuring Flow Pattern Asymmetry of Oil-Water Two Phase Flows Using Multi-channel Rotating Electric Field Conductance Signals

2018 ◽  
Vol 74 (1) ◽  
pp. 25-41 ◽  
Author(s):  
Yuansheng He ◽  
Yingyu Ren ◽  
Yunfeng Han ◽  
Ningde Jin
Keyword(s):  
Electric Field ◽  
Flow Pattern ◽  
Cross Section ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Time Asymmetry ◽  
Pipe Cross Section ◽  
Multi Scale ◽  
Oil Water

AbstractThe present study is a report on the asymmetry of dispersed oil phase in vertical upward oil-water two phase flow. The multi-channel signals of the rotating electric field conductance sensor with eight electrodes are collected in a 20-mm inner diameter pipe, and typical images of low pattern are captured using a high speed camera. With the multi-channel rotating electric field conductance signals collected at pipe cross section, multi-scale time asymmetry (MSA) and an algorithm of multi-scale first-order difference scatter plot are employed to uncover the fluid dynamics of oil-water two phase flow. The results indicate that MSA can characterise the non-linear behaviours of oil-water two phase flow. Besides, the MSA analysis also beneficial for understanding the underlying inhomogeneous distribution of the flow pattern in different directions at pipe cross section.

Detecting the Flow Pattern Transition in the Gas-Liquid Two-Phase Flow Using Multivariate Multi-Scale Entropy Analysis

2019 ◽  
Vol 74 (10) ◽  
pp. 837-848 ◽  
Author(s):  
Yudong Liu ◽  
Dayang Wang ◽  
Yingyu Ren ◽  
Ningde Jin
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Mean Value ◽  
Entropy Rate ◽  
Permutation Entropy ◽  
Phase Flow ◽  
Two Phase ◽  
Multi Scale ◽  
Flow Pattern Transition

AbstractDue to the complex flow structure and non-uniform phase distribution in the vertical upward gas-liquid two-phase flow, an eight-electrode rotating electric field conductance sensor is used to obtain multi-channel conductance signals. The flow patterns of the vertical upward gas-liquid two-phase flow are classified according to the images obtained from a high-speed camera. Then, we employ the multivariate weighted multi-scale permutation entropy (MWMPE) to detect the instability of flow pattern transition in the gas-liquid two-phase flow. Afterwards, we compare the results of the MWMPE with those of the single-channel weighted multi-scale permutation entropy (SCWMPE) and multivariate multi-scale sample entropy (MMSE). The comparison results indicate that, compared with the SCWMPE and MMSE, the MWMPE has superior performance in terms of the high-resolution presentation of flow instability in the gas-liquid two-phase flow. Finally, we extract the mean value of the MWMPE in whole scales and the entropy rate of the MWMPE in the small scales. The results indicate that the normalized mean value and normalized entropy rate of MWMPE are very sensitive to the transitions of flow patterns, thus allowing the detection of the instability of flow pattern transition.

scholarly journals Flow Regime Recognition and Dynamic Characteristics Analysis of Air-Water Flow in Horizontal Channel under Nonlinear Oscillation Based on Multi-Scale Entropy

Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 667 ◽  
Author(s):  
Bo Sun ◽  
He Chang ◽  
Yun-Long Zhou
Keyword(s):  
Working Conditions ◽  
Dynamic Characteristics ◽  
Two Phase Flow ◽  
Flow Regimes ◽  
Horizontal Channel ◽  
Phase Flow ◽  
Two Phase ◽  
Multi Scale ◽  
Wide Range ◽  
Vibration Parameters

Gas-liquid two-phase flow behavior in horizontal channel under heaving motion showed unique dynamic characteristics due to the complex nonlinear interaction. To further establish a description model and investigate the effects of heaving motion on horizontal gas-liquid flow, experiments in a wide range of vibration parameters and working conditions were carried out by combining vibration platform with two-phase flow loop. It was found that the flow regimes under heaving motion showed significant differences compared to the ones expected in steady state flow under the same working conditions. Increasing vibration parameters showed an obvious impact on fluctuation degree of gas-liquid interface by visualizing high-speed photographs. A method based on multi-scale entropy was applied to identify flow regimes and reveal the underlying dynamic characteristics by collecting signals of pressure-difference. The results indicated that the proposed method was effective to analyze gas-liquid two-phase flow transition in horizontal channel under heaving motion by incorporating information of flow condition and change rate of multi-scale entropy, which provided a reliable guide for flow pattern control design and safe operation of equipment. However, for slug-wave and boiling wave flow, an innovative method based on multi-scale marginal spectrum entropy showed more feasible for identification of transition boundary.

Multi-scale symbolic time reverse analysis of gas–liquid two-phase flow structures

2017 ◽  
Vol 28 (01) ◽  
pp. 1750007 ◽  
Author(s):  
Hongmei Wang ◽  
Lusheng Zhai ◽  
Ningde Jin ◽  
Youchen Wang
Keyword(s):  
Nonlinear Systems ◽  
Dynamic Characteristics ◽  
Two Phase Flow ◽  
Flow Structures ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Two Phase ◽  
Multi Scale ◽  
Flow Parameters ◽  
Complex Nonlinear Systems

Gas–liquid two-phase flows are widely encountered in production processes of petroleum and chemical industry. Understanding the dynamic characteristics of multi-scale gas–liquid two-phase flow structures is of great significance for the optimization of production process and the measurement of flow parameters. In this paper, we propose a method of multi-scale symbolic time reverse (MSTR) analysis for gas–liquid two-phase flows. First, through extracting four time reverse asymmetry measures (TRAMs), i.e. Euclidean distance, difference entropy, percentage of constant words and percentage of reversible words, the time reverse asymmetry (TRA) behaviors of typical nonlinear systems are investigated from the perspective of multi-scale analysis, and the results show that the TRAMs are sensitive to the changing of dynamic characteristics underlying the complex nonlinear systems. Then, the MSTR analysis is used to study the conductance signals from gas–liquid two-phase flows. It is found that the multi-scale TRA analysis can effectively reveal the multi-scale structure characteristics and nonlinear evolution properties of the flow structures.

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