Abstract Considering the importance of two-phase flows in narrow rectangular channels and their use in various applications, the hydrodynamics of a co-current air-water two-phase flow in a vertical narrow rectangular channel has been studied. Experiments have been carried out and flow regime maps for vertical upward and vertical downward flows have been plotted based on measured data sets. Flow regimes were identified and classified based on visual observation and void fraction data. Flow visualization was performed using a high speed camera, while a void fraction analysis was done using the electrical impedance method and a digital image analysis. Four different flow patterns were identified for the vertical upward flow and seven flow patterns were identified for the vertical downward flow. The flow regime map for the vertical upward flow was compared with previous studies and also with the flow regime map obtained for the vertical downward flow in this study.

中文翻译：

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窄矩形通道垂直向上和向下气水两相流的流动模式

摘要 考虑到窄矩形通道中两相流的重要性及其在各种应用中的应用，研究了垂直窄矩形通道中并流气水两相流的流体动力学。已经进行了实验，并根据测量数据集绘制了垂直向上和垂直向下流动的流态图。基于视觉观察和空隙率数据识别和分类流态。使用高速相机进行流动可视化，而使用电阻抗法和数字图像分析进行空隙率分析。垂直向上流动确定了四种不同的流动模式，垂直向下流动确定了七种流动模式。