Collaborative Research: Dynamics of Miscible Jets and Drops

1335632/1335666 PI：Fuller/Shen混溶射流和液滴的平移以及液滴的溶解是许多技术过程中遇到的常见事件。了解瞬态界面张力的演变是至关重要的，这是无法测量的。这些挑战激发了PI组最近证明的方法，以提取存在于可混溶液体之间的非常小和瞬时的界面张力。这项合作研究旨在开发一系列互补实验，以了解可混溶液体对的流体动力学，这些液体可以通过各种形式相互作用：混溶射流，混溶悬浮液滴和混溶固着液滴。这些实验将通过与埃因霍温技术大学的安德森教授合作进行的数值模拟来补充。这些多相流系统中的每一个都导致与不混溶液体对所遇到的结果在性质上不同的结果。具体目标是：（1）研究液滴和射流平移通过第二可混溶液体;（2）在微流体环境中经历停滞点延伸流动的可混溶液体的悬浮液滴;（3）在基质液体内扩散和溶解的可混溶液体的固着液滴;以及（4）可混溶悬垂液滴、射流和固着液滴的扩散界面模拟。模拟的结果将与实验测定的射流和液滴的界面形状进行比较。可混溶液体对的动力学以前很少受到关注，但对许多物理过程至关重要。混溶材料的组合可以产生不混溶混合物不可能产生的稳定、复杂的形态。可混溶液体的射流可用于大规模生产否则难以加工的高度取向的纤维。可混溶的固着液滴的溶解是多相流中的一个丰富的问题，其提供了与干燥液滴沿着的有趣类比，以及提取可混溶液体之间的界面张力的可能性。测量界面张力的微流体方法可以应用于其他物理问题，例如经历化学反应的系统，其中界面张力随时间变化。类似的方法也可以适用于掺入不同类型的可混溶流体、液滴和生物分子。该项目将为研究生和本科生提供研究培训。在这个程序中开发的结果也将使精彩的教学工具，介绍流体力学和界面现象的高中和本科生。

1335632/1335666 PI: Fuller/ShenThe translation of miscible jets and drops, and the dissolution of drops are common events encountered in numerous technological processes. It is critical to understand the evolution of the transient interfacial tension, which has eluded measurement. These challenges motivated methods recently demonstrated by the PIs groups to extract very small and transient interfacial tensions existing between miscible liquids. This collaborative research aims to develop a series of complementary experiments to understand the fluid dynamics of miscible pairs of liquids, which can interact with one another through various formats: miscible jets, miscible suspended droplets, and miscible sessile drops. These experiments will be supplemented by numerical simulations in collaboration with Professor Anderson of Eindhoven Technical University. Each of these multiphase flow systems result in outcomes that are qualitatively different from those encountered by immiscible liquid pairs. The specific aims are: (1) studies of drop and jets translating through a second, miscible liquid; (2) suspended droplets of a miscible liquid experiencing stagnation point extensional flow in a microfluidic environment; (3) sessile drops of a miscible liquid spreading and dissolving within a matrix liquid; and (4) diffuse interface simulation of miscible pendant drops, jets and sessile drops. The results from the modeling will be compared against experimental determinations of the interfacial shapes in jets and drops.The dynamics of miscible liquid pairs has received little previous attention but are central to many physical processes. The combination of miscible materials can produce stable, intricate morphologies that are not possible with immiscible mixtures. Jets of miscible liquids can be used to great advantage in the scale-up production of highly oriented fibers that are otherwise difficult to process. The dissolution of miscible, sessile drops is a rich problem in multiphase flow that offers interesting analogies to desiccating drops along with the possibility of extracting measures of the interfacial tension between miscible liquids. The microfluidic approach to measuring interfacial tensions can be applied to other physical problems, such as systems undergoing chemical reactions, where the interfacial tension is changing with time. Similar approaches can also be adapted to incorporate different types of miscible fluids, drops, and biomolecules. The project will provide research training to graduate and undergraduate students. The results developed in this program will also make wonderful teaching tools for the introduction of fluid mechanics and interfacial phenomena to high school and undergraduate students.