The Department of Mechanical Engineering is organizing an Invited Lecture by Prof. Cameron Tropea: 

Date: 25 March 2025 (Tuesday) 

Time: 3:00 PM

Venue: ME Seminar Room 

All are cordially invited to join the lecture. The talk will be followed by Tea at 4:00 PM and an interactive session after that. 

Title: Liquid film rupture

Abstract:

Spontaneously growing holes in liquid films is a fundamental mechanism in atomization, but is also a phenomenon to be avoided in other processes, such as liquid coating. In atomization, these holes proliferate into the intact film with surrounding free rims, driven by surface tension according to the Taylor-Culick mechanism. These expanding holes then merge, leaving a network of ligaments, which breakup due to capillary instability. The question to be addressed is how do holes first appear in a liquid film and what means can be used to influence their formation?

This question was motivated by the observation of a corona detachment in experiments, following drop impact onto a film of different liquid coating a substrate. The corona wall at its base became thinner as the corona rose up, eventually rupturing. The rupture then propagated at very high speed around the entire corona, leading to its detachment. A theory is developed to predict at what thickness and time the corona wall will experience a spontaneous rupture and the resulting predictions are in good agreement with available experimental data. A dimensionless scaling parameter, the Corona number has been introduced to capture the dependence of this phenomenon on the liquid properties.

The talk concludes with an outlook on how this theory can be applied to other applications and how the liquid film rupturing can be intentionally influenced.

Biography:

Cameron Tropea graduated from the University of Toronto in Engineering Sciences, followed by a Masters degree in Mechanical Engineering (1977). He completed his Dr.-Ing. in Civil Engineering at the Technical University of Karlsruhe (1982) and his Habilitation in Fluid Mechanics at the University of Erlangen-Nürnberg (1991) where he was appointed as Professor of Fluid Mechanics until 1997. This was followed by an appointment as head of the Institute of Fluid Mechanics and Aerodynamics at the Technische Universität Darmstadt. Since 2003 Editor-in-Chief of the Springer Nature journal Experiments in Fluids. His research interests include Optical Measurement Techniques in Fluid Mechanics, Interfacial Transport and Wetting Phenomena, Atomization and Spray Processes and Unsteady Aerodynamics. He has been a member of the Scientific Commission of the Council of Science and Humanities in Germany (Wissenschaftsrat) in the period 2016-2022. Prof. Tropea retired from the TU Darmstadt in April 2020 and presently holds the Henry Ford Visiting Professorship Chair at IIT Madras and a VAJRA Faculty position at IISc Bangalore. He is a regular visitor to the Shanghai University for Science and Technology.