Gas–Liquid Flow Behavior Analysis Based on Phase–Amplitude Coupling and ERT

Abstract

Gas–liquid two-phase flow widely exists in industrial production and nature. Studying flow patterns and flow behavior plays an important role in revealing flow mechanism and optimal design of detection equipment. In this article, the flow behavior is studied from the perspective of cross-frequency coupling, and a phase–amplitude coupling method is proposed for flow patterns analysis. First, electrical resistance tomography is adapted to monitor the flow of vertical upward pipeline, and the high-dimensional measurement data were compressed to 16-D. Then, multivariate empirical mode decomposition is used to decompose signals into multiple scales. After that, the coupling between low-frequency phase and high-frequency amplitude is expressed by modulation index, so the information exchange process in multi-scale space can be studied. Analysis of variance is applied in coupling results to determine the scales with the obvious difference in information exchange of different flow patterns. On this basis, the data are visualized to describe the detailed flow structures of each flow patterns and explore the causes of coupling changes. The evolution process of flow patterns is further researched. Finally, the results show that this model can effectively integrate the flow information of different spatial scales and reveal the complex flow behavior.