CAREER: Investigating Fluid Surface Dynamics in Constrained Geometries

Williams College, Williamstown MA

Investigators

Abstract

Non-technical Abstract: When a pipe springs a leak, or raindrops leave streaks of droplets on a windshield, or Cheerios spontaneously clump together in a bowl of milk, we see everyday examples of the dynamics of fluid surfaces. This research project seeks to understand the fundamental science behind these dynamics and related phenomena by developing an experimental laboratory program for exploring and controlling the interactions between fluids and solid surfaces. Using high-magnification microscopes, high-speed videography, and digital image processing, the research team captures complex interactions between surface tension, viscosity, and flow speed as pipes leak, liquids break up into droplets on surfaces, and solid particles form patterns and shatter on the surfaces of fluids. By coupling the experimental observations, data analysis, and theory, this research yields novel insights into the fundamental physics of everyday phenomena that have potential applications in a range of scientific fields and industries. This project also has significant educational impact by affording dozens of undergraduate students opportunities to engage directly in cutting-edge research at a critical stage in their college careers. Technical Abstract: This research program investigates how geometric constraints—both local and global—interact with and change the dynamics of fluid surfaces and their instabilities in two main contexts. The first aim seeks to understand the fundamental physics that governs flow transitions in partially-wetting, thin fluid “leaks,” including rivulet breakup and oscillation cycles between flow start and spontaneous arrest. The second aim explores capillary-driven interactions, spontaneous pattern formation, and Marangoni-driven surface fracture on flat and curved fluid surfaces with adsorbed species from the granular to the macromolecular scale. The research team employs imaging, microscopy, and high-speed videography, and digital image analysis to quantify and understand fluid surface dynamics in custom built, tabletop experiments. Each experimental system is chosen to exemplify key aspects of the overarching research questions, unified by common experimental techniques and governing physical principles. By focusing on the interaction between fluid surface dynamics and constraining geometries in carefully chosen, complementary systems, this research program reveals new, fundamental insights into the rich interplay between surface tension, curvature, flow, jamming, and fracture on fluid surfaces. 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.