CAREER: An integrated study of wave-particle interaction on liquid interfaces

这个CAREER项目将研究毫米级颗粒如何在振动流体表面移动和相互作用。了解小颗粒和液体表面之间的相互作用是一个广泛的研究领域，具有许多应用，包括漂浮垃圾的运输和清除以及雨滴与海面合并产生的气溶胶。文献中的大多数研究都集中在涉及单个颗粒撞击液体表面或多个漂浮颗粒的情况下。然而，一个有趣的制度，这得到了很少的关注，出现时，下面的液体浴垂直振动。在这种情况下，当小液滴与由反弹引起的表面波相互作用时，小液滴可能反弹，甚至沿着液体界面沿着“行走”。该项目的目标是展示这一中间制度的特点新的动态。研究人员将联合收割机实验和理论相结合，研究新的弹跳和行走模式，相互作用的粒子群的行为，以及弹跳粒子和淹没特征之间相互作用产生的新的传输效应。该项目将为高中，本科和研究生提供新的多学科研究经验和教育模块。研究人员将开发一种新的课程，将严格的数学训练与直接接触现实的研究环境交织在一起。该项目还将制定具体举措，向学员灌输强大的沟通技能，包括为学生提供专门的训练营，以培养科学可视化艺术方面的专业知识。将利用交流和可视化工作，通过一系列外展活动促进STEM的多样性。该项目将开发新的实验技术和数学模型，以对毛细血管大小的颗粒和振动液体界面之间的相互作用有一个基本的了解。2005年，Yves Courder和同事发现，一个毫米级的液滴可以自发地沿着振动的流体浴的表面沿着行走，通过与它撞击流体表面时产生的波的共振相互作用而自我推进。凭借与它们的波场的耦合，这些行走的液滴，或“步行者”，表现出令人惊讶的丰富的动力学，包括复杂的弹跳模式，束缚态，和双重波粒行为。这个项目将扩展和利用显着的步行者动力学的基础研究有关的实际设置涉及颗粒材料的液体界面。研究人员将首先专注于扩大弹跳和行走动力学的当前参数范围，以包括不同形状的流体和固体颗粒的新组合。第二个目标将是研究新的自组装和集体动力学与大型合奏的步行者耦合波介导的力量。最终的目的将是检查步行液滴和淹没的功能在液体浴的底部，包括周期性和无序的底部地形之间的相互作用。这类问题将导致更好地理解颗粒和液体界面之间的相互作用，并提供设计原则，为发展新的方法的自组装，颗粒分选，和运输的粒状材料的液体interfaces.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

This CAREER project will investigate how millimeter-size particles move and interact on the surface of a vibrating fluid. Understanding the interplay between small particles and liquid surfaces is a broad area of research with many applications, including the transport and removal of floating litter and aerosol generation from rain drops merging with the sea surface. Most of the studies available in the literature focus on situations involving either a single particle impacting on a liquid surface or multiple floating particles. However, an interesting regime, which has received much less attention, emerges when the underlying liquid bath is vibrated vertically. In this case, small droplets may bounce and even “walk” along the liquid interface as they interact with surface waves caused by rebounds. The goal of this project is to demonstrate new dynamics that characterize this intermediate regime. The investigators will combine experiments and theory to study new bouncing and walking modes, behaviors of groups of interacting particles, and new transport effects emerging from the interaction between bouncing particles and submerged features. This project will provide new multidisciplinary research experiences and educational modules for high school, undergraduate, and graduate students. The investigators will develop a new course that interweaves rigorous mathematical training with direct exposure to realistic research settings. This project will also develop specific initiatives to instill strong communication skills in the trainees, including a dedicated bootcamp for students to develop expertise in the art of scientific visualization. The communication and visualization efforts will be leveraged to promote diversity in STEM through a range of outreach events.This project will develop new experimental techniques and mathematical models to generate a fundamental understanding of the interaction between capillary-size particles and a vibrating liquid interface. In 2005, Yves Courder and co-workers discovered that a millimetric liquid drop can spontaneously walk along the surface of a vibrating fluid bath, self-propelled through a resonant interaction with the waves created when it strikes the fluid surface. By virtue of the coupling with their wave fields, these walking droplets, or “walkers”, exhibit surprisingly rich dynamics, including complex bouncing modes, bound states, and dual wave-particle behaviors. This project will extend and exploit the remarkable walker dynamics for fundamental research relevant to practical settings involving granular materials on liquid interfaces. The investigator will first focus on broadening the current parameter regime of bouncing and walking dynamics to include new combinations of fluids and solid particles of different shapes. The second aim will be to investigate new self-assembly and collective dynamics with large ensembles of walkers coupled by wave-mediated forces. The final aim will be to examine the interaction between walking droplets and submerged features at the bottom of the liquid bath, including periodic and disordered bottom topographies. This class of problems will lead to a better understanding of the interplay between particles and liquid interfaces, and offer design principles for the development of new methods of self-assembly, particle sorting, and transport of granular materials on liquid interfaces.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.