A bouncing droplet can be sustained indefinitely on the surface of a liquid bath that is oscillating vertically. This physical system proves to be extremely rich with fascinating outcomes ranging from the manipulation of droplets without contact to experimental models for pilot wave systems. All these applications rely on the droplet bouncing dynamics which strongly depends on the deformations of the drop/bath system. In a recent paper, we compile a global view of the existing relevant works on the subject, sorting them as a function of the relative drop/bath deformation. More specifically, in the particular case of a non-deformable bath, we identify the crucial role of the droplet deformation in the emergence of complex bouncing trajectories using experiments and numerical simulations.
Using bifurcation diagrams, we experimentally characterize the bouncing modes which can be periodic or chaotic. As a bouncing ball model does not adequately capture the diversity of the observed modes, we are proposing a theoretical model, with the minimum physical ingredients, which is validated by comparing between experiments and numerical simulations. We indeed demonstrate that a bouncing droplet can be modeled using a Kelvin-Voigt material, i.e. a viscoelastic mechanical system.
See D.Terwagne, F.Ludewig, N.Vandewalle and S.Dorbolo, The role of the droplet deformations in the bouncing droplet dynamics, Phys. Fluids 25, 122101 (2013) – PDF