An investigation of oil–water two-phase flow instability using multivariate multi-scale weighted permutation entropy

• Published in: Physica A Vol. 518; pp. 131 - 144
• Main Authors: Han, Yun-Feng, Jin, Ning-De, Zhai, Lu-Sheng, Ren, Ying-Yu, He, Yuan-Sheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2019
• Subjects: Flow instability; Multivariate multi-scale entropy; oil–water two-phase flow; Rotating electrical field conductance sensor; oil–water two-phase flow; Rotating electrical field conductance sensor; Flow instability; Multivariate multi-scale entropy
• ISSN: 0378-4371; 1873-2119
• DOI: 10.1016/j.physa.2018.11.053

The present study is devoted to the investigation of oil–water two-phase flow instability using multivariate multi-scale weighted permutation entropy (MWMPE). Four typical multivariate multi-scale entropies, namely MWMPE, multivariate multi-scale permutation entropy (MMPE), multivariate multi-scale sample entropy (MMSE) and multivariate multi-scale approximate entropy (MMAE) are applied in Lorenz system with the addition of different kinds of noises. The comparison results indicate that MWMPE presents the superiorities of being sensitive to the variation in scale, showing a monotonous increasing trend as well as the best anti-noise ability. Accordingly, with the fluctuating signals from an eight-electrode rotating electrical field conductance sensor used for the measurement of oil–water flows, we extract MWMPE for the whole experimental flow conditions, in terms of which the effects of mixture velocity and water-cut on oil–water two-phase flow instability are illuminated. Our research provides an effective method for uncovering the underlying evolution instability of the flow structures in oil–water flows. •We compare the performances of multivariate multi-scale entropy algorithms in a nonlinear system.•We analyze the differences in the effects of four noises on the performances of entropy algorithms.•We depict flow patterns in vertical upward oil–water flows with low velocity and high water-cut.•We investigate flow instability in oil–water two-phase flow with multivariate conductance signals.