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François Gallaire

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Related publications (151)

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An amplitude equation modelling the double-crest swirling in orbital-shaken cylindrical containers

François Gallaire, Alessandro Bongarzone, Margherita Guido

Container motion along a planar circular trajectory at a constant angular velocity, i.e. orbital shaking, is of interest in several industrial applications, e.g. for fermentation processes or in cultivation of stem cells, where good mixing and efficient ga ...

Cambridge University Press2022

Permeability sets the linear path instability of buoyancy-driven disks

François Gallaire, Pier Giuseppe Ledda, Giuseppe Antonio Zampogna

The prediction of trajectories of buoyancy-driven objects immersed in a viscous fluid is a key problem in fluid dynamics. Simple-shaped objects, such as disks, present a great variety of trajectories, ranging from zig-zag to tumbling and chaotic motions. Y ...

Cambridge University Press2023

Super-harmonically resonant swirling waves in longitudinally forced circular cylinders

François Gallaire, Alessandro Bongarzone, Alice Evelyne Julienne Marcotte

Resonant sloshing in circular cylinders was studied by Faltinsen et al. (J. Fluid Mech., vol. 804, 2016, pp. 608-645), whose theory was used to describe steady-state resonant waves due to a time-harmonic container's elliptic orbits. In the limit of longitu ...

Cambridge University Press2023

Two-dimensional modelling of transient capillary driven damped micro-oscillations and self-alignment of objects in microassembly

François Gallaire

In the fields of microgripping and microassembly, the self-alignment motion of a solid micro-object linked by a liquid meniscus to a substrate or a tool is an inexpensive way to overcome the current limitations of the assembly processes at microscale by ge ...

Cambridge University Press2021

A weakly nonlinear mechanism for mode selection in swirling jets

François Gallaire, Philippe Meliga

Global linear and nonlinear bifurcation analysis is used to revisit the spiral vortex breakdown of nominally axisymmetric swirling jets. For the parameters considered herein, stability analyses single out two unstable linear modes of azimuthal wavenumber m ...

Cambridge University Press2012

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

Absolute/convective secondary instabilities and the role of confinement in free shear layers

François Gallaire

We study the linear spatiotemporal stability of an infinite row of equal point vortices under symmetric confinement between parallel walls. These rows of vortices serve to model the secondary instability leading to the merging of consecutive (Kelvin-Helmho ...

2018

Second-order sensitivity in the cylinder wake: Optimal spanwise-periodic wall actuation and wall deformation

François Gallaire, Edouard Boujo, Andrea Fani

Two-dimensional (2D) flows can be controlled efficiently using spanwise "waviness," i.e., a control (e.g., wall blowing and suction or wall deformation) that is periodic in the spanwise direction. This study tackles the global linear stability of 2D flows ...

AMER PHYSICAL SOC2019

Leidenfrost flows: instabilities and symmetry breakings

François Gallaire

Leidenfrost drops were recently found to host strong dynamics. In the present study, we investigate both experimentally and theoretically the flow structures and stability inside a Leidenfrost water drop as it evaporates, starting with a large puddle. As r ...

CAMBRIDGE UNIV PRESS2022

Self-consistent triple decomposition of the turbulent flow over a backward-facing step under finite amplitude harmonic forcing

François Gallaire, Philippe Meliga, Eunok Yim

We investigate the saturation of harmonically forced disturbances in the turbulent flow over a backward-facing step subjected to a finite amplitude forcing. The analysis relies on a triple decomposition of the unsteady flow into mean, coherent and incohere ...

ROYAL SOC2019

Whirling instability of an eccentric coated fibre

François Gallaire, Edouard Boujo, Ludovic Pierre Gustave Keiser, Shahab Eghbali

We study a gravity-driven viscous flow coating a vertical cylindrical fibre. The destabilisation of a draining liquid column into a downward moving train of beads has been linked to the conjunction of the Rayleigh-Plateau and Kapitza instabilities in the l ...

Cambridge University Press2022

The viscous torsional pendulum

François Gallaire, Francesco Viola

A disk that is free to rotate about its axis and connected to a torsional spring behaves as a damped oscillator when twisted and released. The initial elastic energy is periodically turned to kinetic energy and it gets progressively dissipated by the visco ...

Academic Press Ltd- Elsevier Science Ltd2017

Saturation of the response to stochastic forcing in two-dimensional backward-facing step flow: A self-consistent approximation

François Gallaire, Vladislav Mantic Lugo

Selective noise amplifiers are characterized by large linear amplification to external perturbations in a particular frequency range despite their global linear stability. Applying a stochastic forcing with increasing amplitude, the response undergoes a st ...

Amer Physical Soc2016

Sensitivity and open-loop control of stochastic response in a noise amplifier flow: the backward-facing step

François Gallaire, Edouard Boujo

The two-dimensional backward-facing step flow is a canonical example of noise amplifier flow: global linear stability analysis predicts that it is stable, but perturbations can undergo large amplification in space and time as a result of non-normal effects ...

Cambridge University Press2015

Suppression of von Karman vortex streets past porous rectangular cylinders

François Gallaire, Pier Giuseppe Ledda, Francesco Viola, Lorenzo Siconolfi

Although the stability properties of the wake past impervious bluff bodies have been widely examined in the literature, similar analyses regarding the flow around and through porous ones are still lacking. In this work, the effect of the porosity and perme ...

2018

Environmental Control of Amyloid Polymorphism by Modulation of Hydrodynamic Stress

Giovanni Dietler, François Gallaire, Sandor Kasas, Serguei Sekatski, Jiangtao Zhou, Leonardo Venturelli, Ludovic Pierre Gustave Keiser

The phenomenon of amyloid polymorphism is a key feature of protein aggregation. Unravelling this phenomenon is of great significance for understanding the underlying molecular mechanisms associated with neurodegenerative diseases and for the development of ...

AMER CHEMICAL SOC2021

Fabrication of slender elastic shells by the coating of curved surfaces

François Gallaire, Pedro Miguel Nunes Pereira de Almeida Reis, Gioele Mariano Nicolò Balestra, Pierre-Thomas Paul Brun

Various manufacturing techniques exist to produce double-curvature shells, including injection, rotational and blow molding, as well as dip coating. However, these industrial processes are typically geared for mass production and are not directly applicabl ...

Nature Publishing Group2016

Hydrodynamic loading of perforated disks in creeping flows

François Gallaire, Pedro Miguel Nunes Pereira de Almeida Reis, Lorenzo Siconolfi, Matteo Pezzulla

We present results from an experimental investigation of a viscous fluid driven through and around porous disks at low and moderate Reynolds number conditions: Re = O(10(-4)-10(-3)) and Re = O(1-10). Specifically, we quantify the hydrodynamic drag that the ...

AMER PHYSICAL SOC2019

Frequency selection in a gravitationally stretched capillary jet in the jetting regime

François Gallaire, Isha Shukla

A capillary jet falling under the effect of gravity continuously stretches while thinning downstream. We report here the effect of external periodic forcing on such a spatially varying jet in the jetting regime. Surprisingly, the optimal forcing frequency ...

Cambridge University Press2020

Homogenization theory captures macroscopic flow discontinuities across Janus membranes

Kevin Wittkowski, François Gallaire, Pier Giuseppe Ledda, Giuseppe Antonio Zampogna

Janus membranes, thin permeable structures with chemical and geometrical asymmetric properties, show great potential in industrial separation processes. Yet the link between the micro- and macro-scale behaviours of these membranes needs to be established r ...

Cambridge University Press2023