Investigation of interfacial area concentration transport of bubbly flows in small diameter pipe at normal and micro-gravity environment

双流体模型被认为是最准确、最严谨的两相流模型，广泛应用于机械、核、化工等各种工程领域。双流体模型包括每一相的六个质量方程、动量方程和能量方程。为了使双流体模型更具实用性，必须准确地给出界面面积浓度与驱动力的乘积所给出的界面传递项。本文重点研究了正常和微重力条件下小直径管内泡状流的界面面积输运方程的建立和数据库的建立。正常重力条件下数据库的构建。界面的源项和汇项的建模是重点3。界面输运方程的评价基于上述结果，得出如下结论：1。在正常重力环境下，低雷诺数下的界面输运机制主要是尾迹卷吸。在微重力环境下，低雷诺数下的界面输运机制主要是伪尾迹卷吸。即使在微重力条件下，相间相对速度也不为零。本研究可望为微重力条件下两相流机的设计提供依据。

The two-fluid model is considered most accurate and rigorous model as a two-phase flow analysis utilized in various engineering fields such as mechanical, nuclear and chemical engineering. The two-fluid model consists of six equations of mass, momentum and energy equations for each phase. In order to make the two-fluid model useful, the interfacial transfer term given by the product of the interfacial area concentration and the driving force should be given accurately.This study focuses on the development of the interfacial area transport equation of bubbly flows in a small diameter pipe at normal and microgravity conditions, and the construction of the database.The following researches have been made at relatively low Reynolds number where the effect of the gravity on the flow parameters would be enhanced.1. Construction of the database at normal gravity condition2. Modeling of source and sink terms of the interfacial are a concentration3. Evaluation of the interfacial area transport equationBased on the above results, the following conclusions are obtained as1. The dominant interfacial area transport mechanism at low Reynolds number under normal gravity environment is wake entrainment.2. The dominant interfacial area transport mechanism at low Reynolds number under micro gravity environment is pseudo-wake entrainment.3. The relative velocity between phases is not zero even at micro gravity conditionsThis research is expected to contribute the design criteria of two-phase flow machines at micro gravity conditions.