Instability of Low-Velocity and High Water-Cut Oil–Water Two-Phase Flow Based on Microwave Signals

Abstract

Accurately understanding the nonlinear and complex dynamics underlying low-velocity and high water-cut oil–water two-phase flow is a significant but challenging problem to the study of flow pattern boundary transformation and flow heat transfer. In this article, we propose a nonlinear analysis method to characterize and distinguish patterns from low-velocity and high water-cut oil–water two-phase flow based on the fractional entropy algorithm that have found great usage in complex science. First, we obtain the variable measurement and images of the oil–water two-phase flow by a microwave sensor and a high-speed camera, respectively. Second, we analyze the complexity of flow structure using recurrence algorithms and adaptive optimal kernel time–frequency representation. Finally, we propose a dynamic nonlinear analysis framework to characterize flow instability based on multiscale fractional weighted permutation entropy. The results show that the entropy rate and its mean value are sensitive to the flow structure. These interesting and significant findings suggest that the multiscale fractional weighted permutation entropy can potentially be a powerful tool for uncovering the underlying dynamics leading to the formation of two-phase flow.

Additional information

Funding

This study is supported by National Natural Science Foundation of China (Grant No. 42074142, 51527805).

Notes on contributors

Landi Bai

Landi Bai received the M.Sc. degree from YanShan University, Qinhuangdao, China, in 2019. She started Ph.D. program in the research group of Prof. Ningde Jin in 2019 at Tianjin University. Her research interests are sensor design especially microwave sensor, signal processing and multiphase flow with surfactant, alkali and polymer.

Jing Ma

Jing Ma received the B.Sc. degree from Tianjin University, Tianjin, China, in July 2016. She started Master degree program in the research group of Prof. Ningde Jin in August 2017. Her research interests are high-frequency capacitance sensor design and flow measurement.

Weixin Liu

Weixin Liu received the M.Sc. and Ph.D. degrees from Tianjin University, Tianjin, China, in 2008 and 2018, respectively. He has been a Lecturer in Tianjin Polytechnic University since 2003. His research interests are design in the measurement system of microwave sensor and multiphase flow.

Ningde Jin

Ningde Jin received the Ph.D. degree from Zhejiang University in 1997. He has been a Professor at Tianjin University since 2002. He serves as an Editorial Board Member of Flow Measurement and Instrumentation, and Applied Geophysics. His research interests include the measurement techniques of multiphase flow and well logging technology in borehole geophysics.