Computations of Interface Dynamics in Fluids and Materials

University Of California-Irvine, Irvine CA

Investigators

Abstract

The investigator studies a variety of problems concerning interface dynamics in fluids and materials. The problems are 1) control of droplet formation and 2) microstructral evolution in anisotropic and inhomogeneous elastic media. He brings together physical experiments, modeling, mathematical and numerical analysis, and large-scale scientific computations to study certain fundamental problems related to interface motion, such as interfacial pinch-off and evolutions of interfaces in three-dimensional systems. One of the major goals is to develop and apply start-of-the-art computational tools with emphasis on utilizing adaptive methods and parallel computing, and designing robust numerical methods for integro-differential equations involving multiple physical effects with multiple spatial and temporal scales. The investigator studies some fundamental problems related to multiphase phenomenon in physical systems. In particular, he develops mathematical models and performs large-scale computations to investigate diffusional evolution of microstructure in solid/solid phase transitions and control of droplet formation in a fluid/fluid system. Many structural metals, such as steels, aluminum alloys and superalloys, are products of solid-state diffusional transformations. The multi-phase microstructure resulting from such transformations is a key variable in setting the macroscopic mechanical properties such as stiffness, strength and toughness of the alloy. A goal of this study is to model and simulate the process of microstructure evolution through mathematics and computations, and eventually to provide engineers information on how to generate different microstructures with desirable material properties. The investigation of droplets concerns how to control the formation of drops of many sizes (frequently referred to as satellite drops) in a situation like a dripping faucet or in the breakup of a jet. The presence of satellite drops is undesirable in many practical situations such as in ink jet printers and disk atomizers. He studies the use of focused, external acoustic waves for the control of satellite drops. If successful, this idea can be applied to many modern technologies.