Vendredi 13 mars 2026 à 11h, salle des séminaires IRPHE
Abstract: From melting icebergs to dissolving limestone caves, fluids sculpt the shapes we see around us. This talk presents a mathematical model describing the shape evolution of a body that dissolves or melts under gravitationally stable buoyancy-driven convection, driven by thermal or solutal transfer at the solid-fluid interface. For high Schmidt number (the ratio of momentum to mass diffusion), we can reduce this complex system to a single equation for the shape evolution. Focusing on the particular case of a cone, we can derive complete predictions for the underlying self-similar shapes, intrinsic scales and descent rates. We will present the results of laboratory experiments, which show an excellent match to the theory. By analysing all initial power-law shapes, we uncover a surprising result that the tips of melting or dissolving bodies can either sharpen or blunt with time subject to a critical condition.
Dr Megan Davies Wykes is an Associate Professor in the Department of Engineering at the University of Cambridge, where they are part of the Fluid Dynamics Group. They received their PhD in Mathematics from Cambridge in 2014 and subsequently spent two years as a Fulbright Scholar at New York University. Dr. Davies Wykes's research uses laboratory experiments to uncover the fundamental physics of buoyancy-driven flows. Her work spans a wide range of scales, from microscale swimmers to ocean mixing. In particular, she has worked on particle-driven convection, natural ventilation in buildings, airborne disease transmission, turbulent stratified mixing, and fluid-structure interaction.