Title: Active interface propagation and anisotropic particles dispersion in complex flows
The effect of fluid flows on active interface dynamics or particles transport is relevant to a wide variety of processes such as interface growth in liquids, population dynamics or bacteria transport in fluids. In this talk I will first address the behavior of a self-sustained reaction front in the presence of a disordered flow. Resulting from the balance between molecular diffusion and nonlinear chemical kinetics, autocatalytic reactions can generate traveling fronts, providing a suitable system to study growing interfaces in fluid flows. When coupled to a disordered flow field, these fronts exhibit a complex behavior leading to different propagation regimes with distinct morphologies. I will show that the experimentally measured spatial and temporal fluctuations of the front positions become consistent with three distinct universality classes when tuning a single parameter, i.e. the mean flow velocity. Intriguingly, these fronts can also exhibit frozen steady states with a sawtooth pattern, over a certain range of flow rate.
Séverine Atis is an experimental physicist. She did her PhD at Université Pierre et Marie Curie in Paris on reaction wave fronts propagation in disordered flows. After a year of fellowship in the Mechanical Engineering department at MIT, where she studied anisotropic particles clustering in chaotic flows, she is now a postdoc in David Nelson’s group at Harvard University and works on bacteria range expansion experiments. Her interests include out-of-equilibrium phenomena, internal waves propagation in complex stratification, turbulence and superconductors.
Every Friday 10:45-11:45 a.m., COB 276 (except as noted). Tea and cookies will be served from 10:30 - 10:45 a.m. Questions regarding the seminar series should be directed to Prof. Bin Liu