Publications related to Capillary length

Stability of a liquid layer draining around a horizontal cylinder: Interplay of capillary and gravity forces

François Gallaire, Shahab Eghbali, Simeon Vladimirov Djambov

We study the drainage of a viscous liquid film coating the outside of a solid horizontal cylinder, where gravity acts vertically. We focus on the limit of large Ohnesorge numbers Oh, where inertia is negligible compared to viscous effects. We first study t ...

Amer Physical Soc2024

The Three-Phase Contact Potential Difference Modulates the Water Surface Charge

Aleksandra Radenovic, Andrei Kiselev, Vasily Artemov, Roman Doronin

The surface charge of an open water surface is crucialfor solvationphenomena and interfacial processes in aqueous systems. However, themagnitude of the charge is controversial, and the physical mechanismof charging remains incompletely understood. Here we ...

AMER CHEMICAL SOC2023

Influence of Sphericity on Surface Termination of Icosahedral Colloidal Clusters

Esther Amstad

Colloids self-organize into icosahedral clusters composed of a Mackay core and an anti-Mackay shell under spherical confinement to minimize the free energy. This study explores the variation of surface arrangements of colloids in icosahedral clusters, focu ...

Wiley-V C H Verlag Gmbh2023

Dynamics of cavitation bubbles near granular boundaries

Mohamed Farhat, Davide Bernardo Preso, Armand Baptiste Sieber

We study the dynamics of a cavitation bubble near beds of sand of different grain sizes. We use high-speed imaging to observe the motion of the bubble and the sand for different values of the stand-off parameter gamma (dimensionless bubble-boundary distanc ...

Cambridge University Press2022

Subharmonic parametric instability in nearly brimful circular cylinders: a weakly nonlinear analysis

François Gallaire, Alessandro Bongarzone, Francesco Viola

In labscale Faraday experiments, meniscus waves respond harmonically to small-amplitude forcing without threshold, hence potentially cloaking the instability onset of parametric waves. Their suppression can be achieved by imposing a contact line pinned at ...

Cambridge University Press2022

Decoupling the role of inertia, friction and cohesion in dense granular avalanche pressure build‐up on obstacles

Christophe Ancey, Johan Alexandre Philippe Gaume, Michael Lukas Kyburz

Understanding the physical processes involved in snow avalanche‐obstacle interaction is essential to be able to estimate the pressure exerted on structures. Although avalanche impact pressure has been measured in field experiments for decades, the underlyi ...

2020

Shapes of rotating normal fluid He-3 versus superfluid He-4 droplets in molecular beams

Christoph Bostedt, Andre Al Haddad

Previous single-pulse extreme ultraviolet and x-ray coherent diffraction studies revealed that superfluid He-4 droplets obtained in a free jet expansion acquire sizable angular momentum, resulting in significant centrifugal distortion. Similar experiments ...

AMER PHYSICAL SOC2020

Interaction and breakup of droplet pairs in a microchannel Y-junction

Tobias Schneider, Simon Sebastian Schütz

We combine theory, numerical simulation, and experiments to investigate the breakup of two identical droplets entering a Y-junction with controlled spatial offset by which the second droplet trails the first. Based on fully resolved 3D simulations, we desc ...

AMER PHYSICAL SOC2020

Studying the wettability of Si and eutectic Si-Zr alloy on carbon and silicon carbide by sessile drop experiments

Ludger Weber, Alberto Ortona, Manoj Kondibhau Naikade

The contact angles of two different systems, molten silicon and a eutectic Si-8 at. pct Zr alloy and their evolution over timeon vitreous carbon and polycrystalline silicon carbide (SiC) substrates were investigated at 1500 degrees C under vacuum, as well ...

ELSEVIER SCI LTD2019

Assessment of capillary phenomena in liquid composite molding

Véronique Michaud, Baris Çaglar, Feyza Karasu Kiliç, Cem Tekin

The interplay between capillary and viscous forces plays a significant role for optimal part quality in fiber-reinforced composites manufactured by Liquid Composite Molding (LCM); these are however difficult to analyze during flow. Two approaches are propo ...

2019

Dynamic wetting in pressure-infiltration of ceramic particle preforms by molten metal

Gionata Schneider

This thesis investigates the interaction between mechanically induced flow of a liquid metal into a porous solid, and kinetic effects at the triple line. The approach is experimental and focuses on metal-ceramic systems for which the literature gives value ...

EPFL2019

3D Boundary Element Simulation of Droplet Dynamics in Microchannels: How Droplets Squeeze Through Constrictions and Move in Electric Fields

Simon Sebastian Schütz

Flows of fluids with free surfaces show complex dynamical behavior. Examples include effects like capillary surface waves, topological transitions such as droplet breakup and coalescence, or pattern formation in wetting and de-wetting dynamics. These compl ...

EPFL2018

Viscous Taylor droplets in axisymmetric and planar tubes: from Bretherton’s theory to empirical models

François Gallaire, Gioele Mariano Nicolò Balestra, Lailai Zhu

The aim of this study is to derive accurate models for quantities characterizing the dynamics of droplets of non-vanishing viscosity in capillaries. In particular, we propose models for the uniform-film thickness separating the droplet from the tube walls, ...

2018

Scaling laws for the mechanics of loose and cohesive granular materials based on Baxter's sticky hard spheres

Johan Alexandre Philippe Gaume, Henning Löwe

We have conducted discrete element simulations (PFC3D) of very loose, cohesive, granular assemblies with initial configurations which are drawn from Baxter's sticky hard sphere (SHS) ensemble. The SHS model is employed as a promising auxiliary means to ind ...

2017

Pore-scale analysis of the minimum liquid film thickness around elongated bubbles in confined gas-liquid flows

John Richard Thome, Alessio Ferrari, Mirco Magnini, Albert Matthias Beisel

The fluid mechanics of elongated bubbles in confined gas-liquid flows in micro-geometries is important in pore-scale flow processes for enhanced oil recovery and mobilization of colloids in unsaturated soil. The efficiency of such processes is traditionall ...

Elsevier Sci Ltd2017

Molecular-level characterization of curved water interfaces with sum frequency and second harmonic scattering

Nikolay Smolentsev

Aqueous interfaces are omnipresent in nature. Some of them are visible: droplets in clouds, aerosols, and surfaces of oceans, lakes, and rivers. Many more surfaces are hidden: water in contact with cell membranes, proteins, and the surface of droplets in e ...

EPFL2017

Foam on troubled water: Capillary induced finite-time arrest of sloshing waves

François Gallaire, Francesco Viola, Pierre-Thomas Paul Brun, Benjamin Jérémy Dollet

Interfacial forces exceed gravitational forces on a scale small relative to the capillary length-two millimeters in the case of an air-water interface-and therefore dominate the physics of sub-millimetric systems. They are of paramount importance for vario ...

Amer Inst Physics2016

Investigating The Size-Dependent Static And Dynamic Behavior Of Circular Micro-Plates Subjected To Capillary Force

Simon Nessim Henein, Ilan Vardi, Mohammad Hussein Kahrobaiyan

The size-dependent static deflection, pull-in instability and resonant frequency of a circular microplate under capillary force have been studied using modified couple stress elasticity theory. SiZe-dependency is a phenomenon in which the normalized quanti ...

Amer Soc Mechanical Engineers2016

Computer modelling of the surface tension of the gas-liquid and liquid-liquid interface

Dominic John Tildesley

This review presents the state of the art in molecular simulations of interfacial systems and of the calculation of the surface tension from the underlying intermolecular potential. We provide a short account of different methodological factors (size-effec ...

Royal Society of Chemistry2016

A pancake droplet translating in a Hele-Shaw cell: lubrication film and flow field

François Gallaire, Lailai Zhu

We adopt a boundary integral method to study the dynamics of a translating droplet confined in a Hele-Shaw cell in the Stokes regime. The droplet is driven by the motion of the ambient fluid with the same viscosity. We characterize the three-dimensional (3 ...

Cambridge University Press2016