多相流中界面问题的数值模拟方法及其应用

Interface tracking in multiphase flows is of most interest in many engineering or mathematical problems and many methods have been developed for their numerical resolution in various fields of the physics or the engineering. In the framework of Eluer coordinates, this project uses multi-level set functions to indicate interfaces in multiphase flows. Combined with adaptive techniques and parallel realizations of continuous model, an efficient fast algorithm will be designed to track moving interfaces in multiphase flows. Riemann solver will be constructed to keep many physical properties of moving interfaces and improve the accuracy of simulations on the basis of stabilities. Considering the interactions among different phases near interfaces, detailed heat transfer, mass transfer, kinetic realstions, will be analyzed to establish reliable, physical interface conditions which maintain the important physical properties of the interfaces. With the help of localized MD numerical simulations, some physical parameters could be extracted, so that the method can describe many complicated phenomenon of moving interfaces in complex multiphase flows. About multiphase flow interface problems, from mathematical modeling to algorithm developing, from numerical simulations to data analysis, in the end, a rational solving framework will be constructed and corresponding software will be developed in this project.

多相流动广泛地存在于热能核能、航天航空、化工冶金、汽车船舶、水泥制备、空调环保和水利工程等领域中，其最根本的特点就是流动中伴随着相界面的运动，因此，开展界面问题的研究具有重要的理论意义和应用价值。本项目采用Eluer坐标框架，用多水平集函数来标记多相流中的相间界面，结合自适应、并行化实现基于连续型模型的界面追踪快速算法。通过在界面网格附近构造局部的多介质Riemann问题求解格式，保持界面上的各种物理特性，同时在保证算法稳定的基础上提高模拟精度。考虑界面上不同相之间的相互作用，通过细致的界面传热、传质、动力学分析，建立可靠的、保持重要物理特性的具有应用价值的界面物理模型，利用局部的微观数值模拟提取物理参数，使之可以描述复杂的多相流界面运动现象。对多相流界面问题从数学建模、算法发展、实际计算到数据分析积累经验，初步形成一个合理的问题求解框架，并在此基础上开发计算软件。

多相流是一种广泛存在的流体运动，开展界面问题的研究具有重要的理论意义和应用价值。本项目主要侧重于针对界面上的各种物理特性，设计稳定可行的算法。考虑界面上不同相之间的相互作用，通过细致的界面传热、传质、动力学分析，建立可靠的、保持重要物理特性的具有应用价值的界面物理模型，利用局部的微观数值模拟提取物理参数，使之可以描述复杂的多相流界面运动现象。对多相流界面问题从数学建模、算法发展、实际计算到数据分析积累了经验，初步形成一个合理的问题求解框架，并在传统流体、磁流体以及微流体等不同的应用领域获得了与物理实验相吻合的数值结果。