June 6, 2024 – Seminar Talk by Eric Climent – History force and dynamics of rising spherical droplets
On Thursday, June 6, 2024, 14:00, we will host a seminar by Eric Climent (Institut de Mécanique des Fluides de Toulouse) https://www.imft.fr/pages-personnelles/climent-eric/
Title: History force and dynamics of rising spherical droplets (experiments and simulations)
Room: Animationslabor Cauerstrasse 11, (00.133-128) or remotely (if you want to attend via zoom, please contact cs10-support@fau.de)
Abstract:
We consider a spherical droplet in a uniform steady or unsteady flow. I will first comment on the history force acting on a droplet embedded in an oscillatory flow. Then, we aim at investigating the 3D flow bifurcations inside and outside the viscous droplet, and to identify the range of physical properties yielding flow instability, as well as their consequence on the drop hydrodynamics through the drag and lift forces. The study is based on direct numerical simulations (DNS): the Navier- Stokes equations are solved in both phases, two numerical solvers (i.e. inside and outside the droplet) are coupled by proper interface boundary conditions. Two types of bifurcation are evidenced depending on the viscosity ratio: inside the droplet and in the wake. In agreement with existing literature on 3D flows around a solid sphere, we observe an increase of the drag and the appearance of a lift force when the bifurcation occurs. This leads to instability of the rising path of the droplets.