Intermittent dynamic bursting in vertically vibrated liquid drops

Controlling the partial coalescence of a droplet on a vertically vibrated bath

A new method is proposed to stop the cascade of partial coalescences of a droplet laid on a liquid bath. The strategy consists in vibrating the bath in the vertical direction in order to keep small droplets bouncing. Since large droplets are not able to bounce, they partially coalesce until they reach a critical size. The system behaves as a low pass filter : droplets smaller than the critical size are selected. This size has been investigated as a function of the acceleration and the frequency of the bath vibration. Results suggest that the limit size for bouncing is related to the first mode…

Hole dynamics in vertically vibrated liquids and suspensions

We study the dynamics of holes created in vertically vibrated dense suspensions and viscous Newtonian liquids. We find that all holes oscillate with the driving frequency, with a phase shift of $π/2$. In Newtonian liquids holes always close, while in suspensions holes may grow in time. We present a lubrication model for the closure of holes which is in good agreement with the experiments in Newtonian liquids. The growth rate of growing holes in suspensions is found to scale with the particle diameter over the suspending liquid viscosity. Comparing closing holes in Newtonian liquids to growing …

Equilibrium shapes and floatability of static and vertically vibrated heavy liquid drops on the surface of a lighter fluid

A small drop of a heavier fluid may float on the surface of a lighter fluid supported by surface tension forces. In equilibrium, the drop assumes a radially symmetric shape with a circular triple-phase contact line. We show theoretically and experimentally that such a floating liquid drop with a sufficiently small volume has two distinct stable equilibrium shapes: one with a larger and one with a smaller radius of the triple-phase contact line. Next, we experimentally study the floatability of a less viscous water drop on the surface of a more viscous and less dense oil, subjected to a low fre…

垂直振动圆柱容器中的耦合瑞利-泰勒与法拉第不稳定性

Coupled Rayleigh--Taylor and Faraday instabilities in vertically vibrated cylindrical containers

该研究采用弗洛凯分析探究垂直振动圆柱中瑞利-泰勒与法拉第不稳定性的耦合机制，明确振动振幅、横向约束等因素对不稳定性模式的影响，揭示了受限多相流中界面不稳定性的复杂演化规律。

Vertically-Vibrated Gas-Liquid Interfaces: Surface Deformation and Breakup

In his pioneering work of 1831, Faraday demonstrated that a vertically vibrated gas-liquid interface exhibits a period-doubling bifurcation from a flat state to a wavy configuration at certain frequencies or amplitudes. Typical experiments performed using thin layers of water produce "Faraday ripples", modest-amplitude nonlinear standing waves. Later experiments by Hashimoto and Sudo (1980) and Jameson (1966) as well as those performed in the present study show that much more dramatic disturbances can be generated at the gas-liquid free surface under certain ranges of vibration conditions. Thi…

Faraday instability and subthreshold Faraday waves: surface waves emitted by walkers

A walker is a fluid entity comprising a bouncing droplet coupled to the waves that it generates at the surface of a vibrated bath. Thanks to this coupling, walkers exhibit a series of wave-particle features formerly thought to be exclusive to the quantum realm. In this paper, we derive a model of the Faraday surface waves generated by an impact upon a vertically vibrated liquid surface. We then particularise this theoretical framework to the case of forcing slightly below the Faraday instability threshold. Among others, this theory yields a rationale for the dependence of the wave amplitude to…