相关论文: Avalanches of popping bubbles in collapsing foams
We report experimental measurements of the acoustic emission associated with the bursting of a gas bubble at the free surface of a non-newtonian fluid. On account of the viscoelastic properties of the fluid, the bubble is generally…
Aqueous foams are an important model system that displays coarsening dynamics. Coarsening in dispersions and foams is well understood in the dilute and dry limits, where the gas fraction tends to zero and one, respectively. However, foams…
In order to assess the physical mechanisms at stake when giant gas bubbles burst at the top of a magma conduit, laboratory experiments have been performed. An overpressurized gas cavity is initially closed by a thin liquid film, which…
When a bubble of air rises to the top of a highly viscous liquid, it forms a dome-shaped protuberance on the free surface. Unlike a soap bubble, it bursts so slowly as to collapse under its own weight simultaneously, and folds into a…
Stress vs. strain fluctuations in athermal amorphous solids are an example of `crackling noise' of the type studied extensively in the context of elastic membranes moving through random potentials. Contrary to the latter, we do not have a…
A vortices-bubble system may be depicted by some features which may lead to infer its acoustic charge and its spin angular momentum. We study the dynamics of this system within the framework of fluid physics and with the help of Maxwell's…
Crackling noise is a common feature in many systems that are pushed slowly, the most familiar instance of which is the sound made by a sheet of paper when crumpled. In percolation and regular aggregation clusters of any size merge until a…
Collapsible tubes can be employed to study the sound generation mechanism in the human respiratory system. The goals of this work are (a) to determine the airflow characteristics connected to three different collapse states of a…
We report tensile failure experiments on polyurethane (PU) foams. Experiments have been performed by imposing a constant strain rate. We work on heterogeneous materials for whom the failure does not occur suddenly and can develop as a…
Crackling noise arises when a system responds to changing external conditions through discrete, impulsive events spanning a broad range of sizes. A wide variety of physical systems exhibiting crackling noise have been studied, from…
Key features of the mechanical response of amorphous particulate materials, such as foams, emulsions, and granular media, to applied stress are determined by the frequency and size of particle rearrangements that occur as the system…
Acoustic emission or crackling noise is measured from an experiment on splitting or peeling of paper. The energy of the events follows a power-law, with an exponent $\beta \sim 1.8\pm 0.2$. The event intervals have a wide range, but…
Foaming metals modulates their physical properties, enabling attractive applications where lightweight, low thermal conductivity or acoustic isolation are desirable. Adjusting the size of the bubbles in the foams is particularly relevant…
In wet liquid foams, slow diffusion of gas through bubble walls changes bubble pressure, volume and wall curvature. Large bubbles grow at the expenses of smaller ones. The smaller the bubble, the faster it shrinks. As the number of bubbles…
Acoustic droplet vaporization denotes the phase-change of micron- and sub-micron-sized droplets upon the application of high-amplitude ultrasound. The asymmetric collapse of the incepted vapor bubbles within the droplets can give rise to…
Coarsening of two-phase systems is crucial for the stability of dense particle packings such as alloys, foams, emulsions or supersaturated solutions. Mean field theories predict an asymptotic scaling state with a broad particle size…
Self-oscillations underlie many natural phenomena such as heartbeat, ocean waves, and the pulsation of variable stars. From pendulum clocks to the behavior of animal groups, self-oscillation is one of the keys to the understanding of…
Bubbles display astonishing acoustical properties since they are able to absorb and scatter large amounts of energy coming from waves whose wavelengths are two orders of magnitude larger than the bubble size. Thus, as the interaction…
When a drop impacts a deep pool, it forms a crater which subsequently rebounds. Under certain conditions, a dimple forms at the crater bottom, which pinches off to entrap a small bubble. The oscillation of this entrapped bubble is the…
In these fluid dynamics videos, we show how bubbles flowing in a thin microchannel interact under an acoustic field. Because of acoustic interactions without direct contact, bubbles self-organize into periodic patterns, and spontaneously…