When particles are deposited at a fluid interface they tend to aggregate by capillary attraction minimize the overall potential energy of system. In this work, we embed floating millimetric disks with permanent magnets introduce competing repulsion effect and study their pattern formation in equilibrium. The pairwise landscape two is described short-range long-range (SALR) interaction potential, previously documented number microscopic condensed matter systems. Such interactions enable...

When a millimetric body is placed atop vibrating liquid bath, the relative motion between object and interface generates outward-propagating waves with an associated momentum flux. Prior work has shown that isolated chiral objects, referred to as spinners, can thus rotate steadily in response their self-generated wavefield. Here, we consider case of two cochiral spinners held at fixed spacing from one another but otherwise free interact hydrodynamically through shared fluid substrate. Two...

Bats, the only mammals with powered flight, provide inspiration to engineer highly manoeuvrable flapping wing aerial vehicles due their ability in performing several complex manoeuvres. While straight flight manoeuvres have been extensively studied, drinking not. We studied two insectivorous bat species terms of kinematics and aerodynamics during flight: Hipposideros pratti Rhinolophus ferrumequinum . During drinking, both decrease amplitude simultaneously increase frequency. The angle...

Our work investigates cleaning surfaces coated with protein solutions or bacterial biofilms using continuous collisions and sliding air bubbles in an aqueous medium. Air between 0.5-1 mm radius perform best when tilted at 20-25 degrees respect to the horizontal plane. Based on our model, interplay steady speed film thickness bubble surface yields 22.5 degrees. The technique offers a safe environmentally friendly way of fresh agricultural produce without damaging it reducing its freshness period.

A partially wetting droplet on a substrate behind an obstacle in sufficiently strong wind is found experimentally to depin and move downstream, or upstream, split into two. simple 2D theory gives qualitative prediction of this behavior.

We present experiments and theory for viscous fingering of a suspension non-colloidal particles undergoing radial flow in Hele-Shaw cell. As the displaces air, shear-induced migration causes to move faster than average velocity accumulate on suspension–air interface. The resultant particle accumulation generates pattern which low-concentration, low-viscosity high-concentration, high-viscosity is unstable due classic Saffman–Taylor instability mechanism. While destabilising mechanism...

Inspired by a rain droplet on windshield, we theoretically study the dynamics of partially wetting subject to wind and gravity. Our reduced mathematical model couples pressure drag induced flow separation over drop gravitational force characterize drop's depinning conditions. The results our lubrication reveal limits up-slope depinning, pinning, down-slope for varying sizes speeds. can be used identify optimum windshield angles different ranges

We experimentally investigate the interfacial instability that emerges when a water droplet is deposited on bath of glycerol-water solution. Despite absence surface tension to stabilize short-wavelength undulations, we observe finite-size fingers grow and pinch off from drop. show fingering patterns formed in experiments resultes balance between outward buoyancy effect inward Marangoni flow. This induced flow inhibits small perturbations acts as an effective miscible interface spreading To...

Partially wetting droplets under an airflow can exhibit complex behaviours that arise from the coupling of surface tension, inertia external flow and contact-line dynamics. Recent experiments by Hooshanginejad et al. ( J. Fluid Mech. , vol. 901, 2020) revealed a millimetric partially water droplet impinging jet oscillate in place, split or depin away jet, depending on magnitude (i.e. $5\unicode{x2013}20\ {\rm m}\ s}^{-1}$ ) position jet. To rationalise experimental observations, we develop...

When particles are deposited at a fluid interface they tend to aggregate by capillary attraction minimize the overall potential energy of system. In this work, we embed floating millimetric disks with permanent magnets introduce competing repulsion effect and study their pattern formation in equilibrium. The pairwise landscape two is described short-range long-range (SALR) interaction potential, previously documented number microscopic systems. Such interactions enable variety equilibrium...

The challenge when studying the impact and sliding of free-rising air bubbles on tilted surfaces is an experimental limitation in obtaining film thickness thin liquid (TLF) during bubbles' surfaces. In this work, spatiotemporal evolution moving TLF between a bubble plate was monitored by using two-wavelength synchronized reflection interferometry microscopy (SRIM) technique. directly determined from timed series monochromatic interference fringes recorded simultaneously at two different...

When a millimetric body is placed atop vibrating liquid bath, the relative motion between object and interface generates outward propagating waves with an associated momentum flux. Prior work has shown that isolated chiral objects, referred to as spinners, can thus rotate steadily in response their self-generated wavefield. Here, we consider case of two co-chiral spinners held at fixed spacing from one another but otherwise free interact hydrodynamically through shared fluid substrate. Two...

Abstract

Abstract The motion of bubbles near walls is ubiquitous for cleaning purposes in natural and industrial systems. Shear stress induced by on the surface used to remove particles or bacteria adhering surface. In this study, we investigate effect a coated with protein soil solution without presence an acoustic wave transducer at single frequency. addition, test different drying times surfaces before conducting tests. Our results show that best bubble occurs shortest time coating 100 Hz.

<b><sc>Abstract.</sc></b> Leaves are constantly deforming and vibrating from exposure to blowing wind or impacting raindrops. Previous studies on the motion of a leaf upon drop impact have focused analyzing using cantilever beam theory. However, exhibits more complex dynamic response which involves not only bending motion, but also twisting flapping motions. In this study, we quantified how material properties (e.g., elasticity size) correlate with its fluttering motion. Specifically, peace...

In this study, we experimentally reveal the liquid-like and solid-like behaviors of millimetric liquid marbles when they sediment in oil towards a water layer below. Upon dynamically interacting with oil-water interface, an aqueous armored droplet is shown to either rupture or remain intact as surrounding drop pinches off. The pinch-off novel gravity-driven regime leads double-encapsulation solutions, which enables their secure transport wet environment. We also present scaling laws that...

Oblique collision of solid particles with surfaces has been a topic extensive study in Newtonian mechanics, which also explains the motion bubbles and droplets to some extent. Here, we observe that air exhibit backflipping behavior when they collide tilted surface. Our experiments reveal radii 0.6-0.7 mm undergo at an angle up 15^o strongest 3^o. Particle image velocimetry reveals is caused by wake-induced circulation around bubble, applies lift force on bubble. We develop theoretical model...