PhD defence of Kindness Isukwem

Impact and deformation of viscoplastic drops

Kindness ISUKWEM conducted her PhD research in the CFL team under the supervision of Rudy Valette, Elie Hachem and Anselmo Soeiro Pereira. he will defend her PhD in Computational Mechanics and Materials on October 25th, 2024, in front of the following jury:

M. Philippe COUSSOT Université Gustave Eiffel

M. Gareth MCKINLEY Massachusetts Institute of Technology

Mme Laurence RAMOS Université de Montpellier

M. Christian LIGOURE Université de Montpellier

M. Anselmo PEREIRA Mines Paris, PSL University

M. Rudy VALETTE Mines Paris, PSL University

M. Elie HACHEM Mines Paris, PSL University

M. Romain CASTELLANI Mines Paris, PSL University

Abstract:

This thesis studies the physical mechanisms that drive the impact of viscoplastic drops on surfaces (solid, gas and liquid). Viscoplastic materials have both solid and liquid characteristics, behaving as a solid under low stress and flowing like a liquid under high stress. This dual nature makes the study of their impact dynamics complex and interesting. The research aims to understand the mechanisms behind drop spreading, penetration, and breakup upon impact, considering various parameters such as drop properties, impact velocity, and surface characteristics.

It highlights the importance of understanding viscoplastic drop dynamics for applications in industries such as coatings, inkjet printing, and bioprinting. The study also opens avenues for future research in improving numerical methods and exploring more complex drop impact scenarios.

Overall, the research provides significant insights into the behavior of viscoplastic drops during impact, combining experimental observations with advanced numerical simulations to enhance the understanding of these complex phenomena.

Keywords: rheology, interfacial fluid dynamics, drop impact, numerical simulations