基于递归图的两相流流动特性分析与流型识别

Flow Characteristics Analysis and Flow Pattern Recognition of Two-phase Flow Based on Recurrent Plot

基于数字化电阻层析成像(ERT)系统采集的垂直管道气液两相流实验数据,通过计算不同时刻系统采集的数据均值,生成一维时间序列并进行相空间重构,绘制递归图。对绘制的递归图进行阈值分割,并分析了两相流流动特性。计算了不同流型对应无阈值递归图的图像信息熵范围:泡状流为0.570~0.660;泡状流到弹状流过渡流型为2.300~3.200;弹状流为3.650~4.100;段塞流为4.300~4.600;段塞流到混状流过渡流型为4.650~4.950。结果表明各流型递归图图像信息熵范围分隔明显,可有效识别这5种流型。

Based on the experimental data of gas-liquid two-phase flow in vertical pipeline collected by digital electrical resistance tomography(ERT)system,one-dimensional time series are generated by calculating the mean value of the data collected at different times,and the phase space is reconstructed to draw its recurrent plot.After threshold segmentation,the two-phase flow characteristics can be analyzed effectively.At the same time,the range of image information entropy of different flow patterns corresponding to threshold free recurrent plot is calculated as follows:bubbly flow,0.570~0.650;transition flow pattern from bubbly flow to slug flow,2.300~3.200;slug flow,3.650~4.100;plug flow:4.300~4.600,and flow pattern from plug flow to mixed flow:4.650~4.950.The range of information entropy of each flow pattern recursion graph image is obviously separated,which can effectively identify five flow patterns.