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.
Biography:
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
