Computations of Interface Dynamics in Fluids and Materials

研究者研究流体和材料中有关界面动力学的各种问题. 问题是：1）液滴形成的控制; 2）各向异性和非均匀弹性介质中的微结构演化。 他汇集了物理实验，建模，数学和数值分析，以及大规模的科学计算来研究与界面运动有关的某些基本问题，如界面夹断和三维系统中界面的演化。 主要目标之一是开发和应用最先进的计算工具，重点是利用自适应方法和并行计算，并为涉及多个空间和时间尺度的多物理效应的积分微分方程设计鲁棒的数值方法。 研究者研究物理系统中与多相现象有关的一些基本问题。 特别是，他开发了数学模型，并进行了大规模的计算，以研究在固体/固体相变和控制液滴形成在流体/流体系统中的微结构的扩散演化。 许多结构金属，如钢、铝合金和高温合金，都是固态扩散转变的产物。 这种转变产生的多相显微组织伊萨决定合金的刚度、强度和韧性等宏观力学性能的关键变量。 本研究的一个目的是通过数学和计算对微结构演化过程进行建模和模拟，并最终为工程师提供如何生成具有所需材料性能的不同微结构的信息。 液滴的研究涉及到如何在滴水的水龙头或射流破裂的情况下控制许多尺寸的液滴（通常称为卫星液滴）的形成。 在许多实际情况下，如喷墨打印机和圆盘雾化器中，卫星液滴的存在是不希望的。 他研究使用聚焦的外部声波来控制卫星坠落。 如果成功，这个想法可以应用于许多现代技术。

The investigator studies a variety of problems concerninginterface dynamics in fluids and materials. The problems are 1)control of droplet formation and 2) microstructral evolution inanisotropic and inhomogeneous elastic media. He brings togetherphysical experiments, modeling, mathematical and numericalanalysis, and large-scale scientific computations to studycertain fundamental problems related to interface motion, such asinterfacial pinch-off and evolutions of interfaces inthree-dimensional systems. One of the major goals is to developand apply start-of-the-art computational tools with emphasis onutilizing adaptive methods and parallel computing, and designingrobust numerical methods for integro-differential equationsinvolving multiple physical effects with multiple spatial andtemporal scales. The investigator studies some fundamental problems relatedto multiphase phenomenon in physical systems. In particular, hedevelops mathematical models and performs large-scalecomputations to investigate diffusional evolution ofmicrostructure in solid/solid phase transitions and control ofdroplet formation in a fluid/fluid system. Many structuralmetals, such as steels, aluminum alloys and superalloys, areproducts of solid-state diffusional transformations. Themulti-phase microstructure resulting from such transformations isa key variable in setting the macroscopic mechanical propertiessuch as stiffness, strength and toughness of the alloy. A goal ofthis study is to model and simulate the process of microstructureevolution through mathematics and computations, and eventually toprovide engineers information on how to generate differentmicrostructures with desirable material properties. Theinvestigation of droplets concerns how to control the formationof drops of many sizes (frequently referred to as satellitedrops) in a situation like a dripping faucet or in the breakup ofa jet. The presence of satellite drops is undesirable in manypractical situations such as in ink jet printers and diskatomizers. He studies the use of focused, external acoustic wavesfor the control of satellite drops. If successful, this idea canbe applied to many modern technologies.