中文摘要：

通过建立质量守恒方程和弹状流稳定存在条件等方程,对摇摆状态下竖直管内充分发展的弹状流单元物理模型进行解析。在此基础上,给出摇摆状态下弹状流平均空泡份额计算关系式,并与实验值进行比较,结果符合较好。因此,该弹状流单元物理模型是进一步分析摇摆状态下弹状流流动特性的基础。

英文摘要：

The slug flow unit model in rolling vertical tube was analyzed in this paper, by setting up some equations, such as mass conversation equations and the necessary conditions for the existence of slug flow. Based on this slug flow unit model, the correlation for calculating average void fraction of slug flow in rolling tube was presented, and the calculations were agreed well with experimental data. So, this slug flow unit model could be used as the basis for further analyzing the flow property of slug flow under rolling condition.