Feature extraction and identification of gas-liquid two-phase flow based on fractal theory

Due to the gas-liquid two-phase flow system with nonlinear characteristics, the fractal theory has a significant impact on nonlinear analysis, so the paper proposes applying the fractal theory to characterize the fractal characteristics of two-phase flow. Firstly, it performs the mathematical morphology fractal dimension (MMFD) to analyse the fractal dimension of typical signals, and the box-counting dimension is employed as a comparison. The results indicate that the MMFD has better accuracy in estimating the fractal dimension of the typical signals. The MMFD can reflect the complexity and nonlinear of a chaotic system; Finally, it applies the MMFD to extract features and analyse two-phase flow characteristics. The experimental results show that the MMFD can effectively identify signals of different flow patterns, especially the transitional flow pattern, and reflect the complexity of gas-liquid two phases.