Refined composite multivariate multiscale fuzzy entropy analysis of horizontal oil-water two-phase flow

Horizontal oil-water two-phase flow is widely encountered in power plants, chemical engineering and petroleum industry. Understanding the flow characterization of horizontal oil-water two-phase is significant to uncover the flow mechanics underlying oil-water flow, which will facilitate the safety design and optimization of the process engineering and facilities. Oil-water two-phase flow experiments were conducted with a 16-electrode Electrical Resistance Tomography (ERT) in a horizontal pipe of a multiphase flow facility. The ERT can measure the information of each flow condition from different directions along the cross-section of the pipe, where the electrodes are excited. We extracted the Refined Composite Multivariate Multiscale Fuzzy Entropy (RCmvMFEp) of each flow condition by regarding the multichannel signal of ERT data as multivariate time series. It was found that RCmvMFEp reflects the differences of flow structure between different flow patterns, such as Do/w&w, Dw/o&Do/w (DD), ST&MI to DD and o/w flow. The results indicate that RCmvMFEp approach can characterize the structural complexity of dynamic flow behavior of oil-water two-phase flow and uncover the flow pattern transition when flow velocity changes.