Dynamics and transport related to jets from bursting bubbles with immiscible compound surfaces
- Event Type
- Seminar/Symposium
- Sponsor
- Mechanical Science and Engineering
- Location
- 4100 Sidney Lu Mechanical Engineering Building
- Date
- Dec 11, 2025 4:00 pm
- Speaker
- Zhengyu Yang, Mechanical Science and Engineering, University of Illinois
- Contact
- Amy Rumsey
- rumsey@illinois.edu
- Phone
- 217-300-4310
- Views
- 7
- Originating Calendar
- MechSE Seminars
Abstract
When a bubble bursts at an air-liquid interface, the collapse of the bubble cavity generates an upward jet that can fragment into small droplets. Since these droplets can remain suspended in the air as a key source of aerosols for water-to-air transport, this jetting phenomenon has been studied over decades due to its significance in a wide range of topics, including cloud-forming marine aerosols, and airborne transport of microplastic particles as well as respiratory pathogens. Despite this interest, the influences of contaminants originating from various natural or industrial sources on the bubble bursting jets remain poorly understood. In this talk, I will present our recent progress on jetting dynamics associated with the bursting of bubbles contaminated by an immiscible compound layer. First, we show that jet drops from such contaminated bubbles can be a few microns, while prior studies report that the bursting of such a millimeter-sized bare bubble produces jet drops with a size of the order of 100 µm. The faster and smaller jet drops result from the singular dynamics of the oil-coated cavity collapse, and the air-oil-water compound interface allows singular jets over a much wider parameter space beyond that of a bare bubble. Secondly, we develop a linearized wave-damping model and propose a revised Ohnesorge number that captures the jet radius across a wide range of coating viscosities and thicknesses. Thirdly, we report the entrainment of an immiscible droplet resulting from the cavity collapse and derive a scaling law that predicts the entrained droplet size. Together, these results not only advance the fundamental understanding of contaminated bubble bursting, but also provide guidance and modeling constraints for bubble-mediated contaminant transport in natural and industrial settings.
About the Speaker
Zhengyu Yang is a doctoral candidate in the Department of Mechanical Science and Engineering at the University of Illinois Urbana-Champaign, working in the Fluids, Interfaces & Transport (FIT) Laboratory under the supervision of Prof. Jie Feng. His research interests include fluid dynamics and interfacial phenomena related to bubble dynamics. His doctoral work focuses on experimental and theoretical investigations of bubble bursting dynamics at compound surfaces, including oil-coated and protein-laden surfaces. He is a recipient of the Warren W. Yee Memorial Fellowship (2024) and the Hassan Aref Memorial Award for Theoretical and Applied Mechanics (2022).
Host: Professor Jie Feng