水平气液两相流流型空间图像信息复杂性测度分析

To discuss the relationship between complexity measures extracted from gray image time series and flow pattern transition in gas-liquid two-phase flow,three complexity measures,including Lempel-Ziv complexity,fractal box dimension,and Shannon information entropy were extracted from sixty flow pattern image signals of gas-liquid two-phase flow in the horizontal pipe by using digital high speed video systems.Based on the above studies,the chaos dynamic characteristics of three complexity measures in different gas superficial velocities,and the recognition capability of gas-liquid two-phase flow pattern were analyzed.The results indicated that these three complexity measures were sensitive to the flow pattern transition in gas-liquid two-phase flow.By analyzing the changes of three complexity measures with gas-liquid two-phase flow parameters,the dynamics structure inversion characteristics of gas-liquid two-phase flow could be got,which provided an efficient,supplementary diagnostic tool to reveal the flow pattern transition mechanism of gas-liquid two-phase flow and quantitatively identify flow pattern.

气固流化床流型空间图像信息多重分形特征分析

以无色小粒径玻璃珠和空气为实验介质,利用高速摄影系统在气固流化床实验装置上拍摄,并获取到气固流化床5种典型流型的空间图像信息。采用多重分形谱参数分层次地刻画了流型空间信息内部的精细结构,突出了异常局部变化特征,从复杂的流型图像数据中选出具有明显个性特征,与分形盒维数结合表征流型。结果表明,多重分形谱比简单的分形盒维数能提供更多的流型特征的信息,且流型特征的提取结果更符合实际情况,可被有效地用于气固流化床流型识别和运动机理分析的过程中。

直接接触传热性能综合测试平台的搭建及应用

为了促进学生对理论知识的理解、提升学生实践能力、强化学生创新思维,针对直接接触换热过程设计了传热性能综合测试平台。利用实验平台可开展直接接触式换热器出口工质蒸发量、罐体温度场、容积换热系数及换热流型图像等测量实验,还可根据实验教学需求增加间壁式换热器并联管路进行拓展实验。实践应用表明,实验平台既可让教师进行直接接触换热特性教学和科研研究,又可让学生直观体验、学习科研过程和方法,在高校实验室中具有较好的推广价值。