Related papers: Collision efficiency of droplets across diffusive,…
We consider analytically and numerically head-on collision between two self-propelled drops. Each drop is driven by chemical reactions that produce or consume the concentration isotropically. The isotropic distribution of the concentration…
Droplet velocities used in impact studies were investigated using high-speed photography. It was determined that droplets do not reach terminal velocity before a typical impact, raising the question of how to predict impact velocity. This…
A new experimental technique for creating and imaging collisions of micron-sized droplets settling under gravity is presented. A pair of glycerol droplets is suspended in air by means of two optical traps. The droplet relative velocities…
In our daily lives, after shaking a salad dressing, we see the coarsening of oil droplets suspended in vinegar. Such a demixing process is observed everywhere in nature and also of technological importance. For a case of high droplet…
A droplet falling toward a solid surface displaces the surrounding air until it encounters a defect, and contact nucleates. On atomically smooth surfaces devoid of defects, contact can be delayed until the droplet rebounds; however, above a…
Rainfall from ice-free cumulus clouds requires collisions of large numbers of microscopic droplets to create every raindrop. The onset of rain showers can be surprisingly rapid, much faster than the mean time required for a single…
We propose here a new mechanism of droplet coarsening in phase-separating fluid mixtures. In contrast to the conventional understanding that there are no interactions between droplets in the late stage of spinodal decomposition, we…
We study the rolling and sliding motion of droplets on a corrugated substrate by Molecular Dynamics simulations. Droplets are driven by an external body force (gravity) and we investigate the velocity profile and dissipation mechanisms in…
Assuming perfect collision efficiency, we demonstrate that turbulence can initiate and sustain the rapid growth of very small water droplets in air even when these droplets are too small to cluster, and even without having to take gravity…
When cloud particles are small enough, they move with the turbulent air in the cloud. On the other hand, as particles become larger their inertia affects their motions, and they move differently than the air. These inertial dynamics impact…
Single free-falling freshwater drops were generated with no initial velocity by hypodermic needles, at an altitude of 3.61 m above a still freshwater surface. High resolution high speed videos (0.13 mm/pixel, 500 frames/second) of the…
We study the dynamics of collisions between a pair of uncharged conducting droplets under the influence of a uniaxial compressional flow and an external electric field. The near-field asymptotic expression for the electric-field-induced…
The collisional dynamics of two symmetric droplets with equal intraspecies scattering lengths and particle number density for each component is studied by solving the corresponding extended Gross-Pitaevskii equation in two dimensions by…
It was previously shown that the superdroplet algorithm for modeling the collision-coalescence process can faithfully represent mean droplet growth in turbulent clouds. But an open question is how accurately the superdroplet algorithm…
We examine the dynamics of two coalescing liquid drops in the `inertial regime', where the effects of viscosity are negligible and the propagation of the bridge front connecting the drops can be considered as `local'. The solution fully…
Ambient air cushions the impact of drops on solid substrates, an effect usually revealed by the entrainment of a bubble, trapped as the air squeezed under the drop drains and liquid-solid contact occurs. The presence of air becomes evident…
This article discusses a potential impact of turbulent velocity fluctuations of the air on a drizzle formation in Cumulus clouds. Two different representations of turbulent velocity fluctuations for a microphysics formulated in a Lagrangian…
We study drop impacts on immiscible viscous liquid pool and investigate the formation of droplet surface craters using experimental and theoretical analysis. We attribute the formation of air craters to the rapid deceleration of the droplet…
This paper experimentally investigates the effect of viscosity on the outcomes of collisions between a regular stream of droplets and a continuous liquid jet. A broad variation of liquid viscosity of both the drop and the jet liquid is…
Hypothesis: Interfacial instabilities cause undesirable droplet breakage during impact. Such breakage affects many applications, such as printing, spraying, etc. Particle coating over a droplet can significantly change the impact process…