Abstract The knowledge of wave structure and velocity is of great importance to the prediction of annular two-phase flow phenomena. Given that most existing experimental studies focus on the low liquid flow rate, the goal of this study is to extend the understanding of wave characteristics to high liquid flow rate annular flow, i.e. wispy annular flow. Conductance film thickness probes have been used to measure the film structure of upward annular flow at a high temporal resolution. The inlet superficial gas velocity ranges from 10 m/s to 30 m/s and the range of inlet superficial liquid velocity is from 0.06 m/s to 2 m/s. Important parameters including average film thickness, wave height, base film thickness, wave frequency, wave velocity, and interfacial shear stress are measured and analyzed. Existing models for predicting these parameters are comprehensively reviewed and evaluated using the new data. The evaluation results indicate that although these models are developed for annular flow with low liquid flow rates, some of them can also be used in wispy annular flow with reasonable prediction accuracy, except for wave velocity models. The measured wave velocity in wispy annular flow is significantly higher than that in typical annular flow. A new correlation for wispy annular flow wave velocity is developed based on the new data.

中文翻译：

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垂直向上环形两相流中的波结构和速度

摘要 波浪结构和速度的知识对于环形两相流现象的预测具有重要意义。鉴于大多数现有的实验研究都集中在低液体流速上，本研究的目标是将波浪特征的理解扩展到高液体流速环形流，即纤细的环形流。电导膜厚度探头已被用于以高时间分辨率测量向上环形流的膜结构。入口表观气体速度范围为10 m/s至30 m/s，入口表观液体速度范围为0.06 m/s至2 m/s。测量和分析了重要参数，包括平均膜厚、波高、基膜厚度、波频率、波速和界面剪切应力。使用新数据全面审查和评估用于预测这些参数的现有模型。评估结果表明，虽然这些模型是为低液体流速的环流开发的，但除了波速模型外，其中一些模型也可以用于具有合理预测精度的纤细环流。在纤细环状流中测得的波速明显高于典型环状流中的波速。基于新数据开发了纤细环形流动波速度的新关联。在纤细环状流中测得的波速明显高于典型环状流中的波速。基于新数据开发了纤细环形流动波速度的新关联。在纤细环状流中测得的波速明显高于典型环状流中的波速。基于新数据开发了纤细环形流动波速度的新关联。