相关论文: Can mosquitoes fly in the rain?
The effects of purely elastic collisions on the dynamics of heavy inertial particles is investigated in a three-dimensional random incompressible flow. It is shown that the statistical properties of inter-particle separations and relative…
Small drops impinging angularly on thin flowing soap films frequently demonstrate the rare emergence of bulk elastic effects working in-tandem with the more common-place hydrodynamic interactions. Three collision regimes are observable: (a)…
The bottle-flip challenge -- the upright landing of a partially filled bottle after tossing and flipping it in the air -- unexpectedly became a viral mechanics exercise. Through high-speed visualization, we evidence that fluid content…
Thin, viscous liquid films subjected to impact events can deform. Here we investigate free surface oil film deformations that arise due to the air pressure buildup under the impacting and rebouncing water drops. Using Digital Holographic…
In this fluid dynamics video, results from high fidelity numerical simulations are presented, which have been carried out to study the flow and droplet dynamics of liquid sheets formed by two impinging jets. A three-dimensional…
The spontaneous migration of droplets on conical fibers is studied experimentally by depositing silicone oil droplets onto conical glass fibers. Their motion is recorded using optical microscopy and analysed to extract the relevant…
This fluid dynamics video presents experiments and simulations of gravity-driven particulate jets in viscous fluids at low Reynolds number. An initially straight jet is shown to develop varicose modulations of its diameter as it sediments…
Would a raindrop impacting on a coarse beach behave differently from that impacting on a desert of fine sand? We study this question by a series of model experiments, where the packing density of the granular target, the wettability of…
It is commonly assumed that fluid cannot slip along a solid surface. The experimental evidence generally supports this assumption. We demonstrate that when the change of the relative velocity of a fluid and a solid wall is sufficiently…
Insects and birds are often faced by opposing requirements for agile and stable flight. Here, we explore the interplay between aerodynamic effort, maneuverability, and stability in a model system that consists of a $\Lambda$-shaped flyer…
When a liquid droplet impacts a vibrated micro-structured surface with asymmetric topology, the liquids perform a horizontal motion during its bouncing. The moving effect is observed when the liquid is in contact with a low surface energy…
Numerical simulation of high-speed turbulent water jets in air and its validation with experimental data has not been reported in the literature. It is therefore aimed to simulate the physics of these high-speed water jets and compare the…
Particle-particle and particle-wall collisions occur in many natural and industrial applications such as sedimentation, agglomeration, and granular flows. To accurately predict the behavior of particulate flows, fundamental knowledge of the…
When a micron-sized water droplet impacts on a freely suspended soap film with speed $v_{i}$, there exists a critical impact velocity of penetration $v_{C}$. For the droplet with $v_{i}<v_{C}$, it flows with the soap film after the impact…
A moving contact line occurs at the intersection of an interface formed between two immiscible liquids and a solid. According to viscous theory, the flow is entirely governed by just two parameters, the viscosity ratio, $\lambda$, and the…
The non-linear interaction between air and a water droplet just prior to high-speed impingement on a surface is a phenomenon that has been researched extensively and occurs in a number of industrial settings. The role that surface…
We revisit the reliability of metallicity estimates of high velocity clouds with the help of hydrodynamical simulations. We quantify the effect of accretion and viewing angle on metallicity estimates derived from absorption lines. Model…
Probing the fluid dynamics of thin films is an excellent tool to study the solid/liquid boundary condition. There is no need for external stimulation or pumping of the liquid due to the fact that the dewetting process, an internal…
When an immiscible oil drop is immersed in a stably stratified ethanol-water mixture, the Marangoni flow on the surface of the drop can experience an oscillatory instability, so that the drop undergoes a transition from levitating to…
This paper is devoted to the analysis of a reaction-diffusion system with strong competition and spatial heterogeneities modelling the interaction between two species of mosquitoes. In particular, we propose a mathematical model that…