管道泡状流相分布模式和分布机理研究进展

对管道泡状流的相分布模式和分布机理进行了详细的回顾和介绍。从前人研究的结果发现，相分布与流动条件有关，对于小管径泡状上升流，相分布主要表现为壁面峰值分布、中间峰值分布、中心峰值分布、过渡分布和扁平分布模式；而对于小管径泡状下降流，相分布主要表现为偏离中心峰值分布、钟形分布和中心峰值分布模式。然而对于大管径泡状流，相分布与流向无关，主要表现为壁面峰值分布和中心峰值分布两种模式。除此之外，还存在双峰分布模式和双鞍分布模式。影响相分布的主要因素有气泡尺寸、管道尺寸、气液相速度、气泡的注入位置和注入方法、重力水平，而气泡尺寸为关键因素。调查发现，到目前为止仍未形成一个可以解释所有相分布模式的通用机理。部分物理现象仅通过分析升力、湍流扩散力、壁面斥力以及其他力的平衡给予定性分析。未来应进一步研究相间作用力模型、湍流相干结构对气泡输运机理等问题。

Phase distribution pattern and mechanism of bubbly flow in pipes

Phase distribution pattern and mechanism of bubbly flow in pipes are reviewed. Depending on flow condition，phase distribution shows the wall-peaked profile，the intermediate-peaked profile，the core-peaked profile，the transition profile，and the flat profile for the upward flow in a small diameter pipe，whereas it shows the off-center-peaked profile，the bell-typed profile，and the core-peaked profile for the downward flow. For the flow in the pipe with a large diameter，phase distribution shows only the wall-peaked and the core-peaked profile，independent of flow direction. Additional phase distribution patterns，such as the double-peaked and the double-saddle profile，are also reported. The main factors affecting phase distribution are bubble diameter，pipe diameter，gas/liquid velocity，injection place，injection method，and gravity level. Of these factors，bubble diameter is the most important for phase distribution. A general mechanism，which can be used to explain all phase distribution phenomena，has still not been developed up to now. Part of physical phenomena can be qualitatively explained by lift force in combination with turbulence dispersion force，wall repulsion force，or others. Future studies should focus on investigating the interphase force model，the bubble transport mechanism by turbulence coherent structures，etc.