基于时移多尺度等概率符号化样本熵的气液两相流动态特性分析OA

To reveal the differences in complexity and instability between gas-liquid two-phase flow structures,an analysis method based on time-shift multiscale equiprobable symbolic sample entropy(TMESSE)is proposed.Based on the analysis of seven typical time series,the feasibility and effectiveness of the proposed method are fully verified;subsequently,an in-depth analysis is conducted on the differential pressure fluctuation time series of gas-liquid two-phase flow in a vertical upward pipe.The results indicate that the distribution trend of TMESSE entropy values can characterize the evolutionary characteristics of different flow patterns across multiple scales.Furthermore,the joint distributions of the TMESSE mean value and the complexity indices can qualitatively depict the differences in flow instability under different conditions and,on this basis,quantitatively map the comprehensive instability degree of gas-liquid two-phase flow structures across multiple scales.