报告题目：Simulation Technique for Robust Three-Phase (gas-liquid-solid) Interactions 

　　报告人:      Lucy T. Zhang （章彤）Associate Professor 

　　Department of Mechanical, Aerospace & Nuclear Engineering (MANE) 

　　Rensselaer Polytechnic Institute (RPI) 

　　时间：2017年5月18日(周四)  9:30 

　　地点：中科院力学所会议1号楼344会议室 

　　报告摘要： 

　　In this talk, we show a robust numerical framework to model and simulate gas-liquid-solid three-phase flows. The overall algorithm adopts a non-boundary-fitted approach that avoids frequent mesh-updating procedures by defining independent meshes and explicit interfacial points to represent each phase. The coupling between the phases is done via RKPM meshfree interpolation functions. In this framework, we couple our existing solvers, the immersed finite element method (IFEM) and the connectivity-free front tracking (CFFT) method that model fluid-solid and gas-liquid interactions, respectively, for the three-phase models. A modified IFEM algorithm is derived for modeling fluid-solid interactions that accounts for the dynamics of the solid, while the CFFT is used here to simulate gas-liquid multi-fluid flows that uses explicit interfacial points to represent the gas-liquid interface and for its easy handling of interface topology changes. Instead of defining different levels simultaneously as used in level sets, an indicator function naturally couples the two methods together to represent and track each of the three phases. Several 2-D and 3-D testing cases are performed to demonstrate the robustness and capability of the coupled numerical framework in dealing with complex three-phase problems, in particular free surfaces interacting with deformable solids. The solution technique offers accuracy and stability, which provides a means to simulate various engineering applications that involve high Reynolds number flows, large deformations, and high density disparities among the phases. 

　　报告人简介： 

　　Lucy T. Zhang是美国伦斯勒理工学院（Rensselaer Polytechnic Institute，RPI）副教授。1998年于纽约州立大学宾汉姆顿分校获得学士学位，2000和2003年于西北大学分别获得硕士和博士学位。2006年加入RPI美国伦斯勒理工学院机械、航空与核工程系。目前已经表论文60余篇，总引用次数达1300多次。 

　　Lucy T. Zhang的研究方向主要针对生物医学中的力学系统和物理问题，建立高效的力学计算方法，开发和设计相应计算软件。涵盖的研究领域有：计算流体动力学和计算固体力学、流固耦合计算方法、计算生物力学、纳尺度界面分子模拟等。