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François Gallaire

Cette personne a quitté l’EPFL

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Publications associées (151)

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Adjoint-aided Homogenisation for Flows Through Heterogeneous Membranes

François Gallaire, Edouard Boujo, Kevin Wittkowski

Porous membranes, like nets or filters, are thin structures that allow fluid to flow through their pores. Homogenisation can be used to rigorously link the flow velocity with the stresses on the membrane via several coefficients (e.g. permeability and slip ...

CAMBRIDGE UNIV PRESS2025

Numerical simulation and sensitivity analysis of a low-Reynolds-number flow around a square cylinder controlled using plasma actuators

François Gallaire, Edouard Boujo, Philippe Meliga

Flow around a square cylinder controlled using plasma actuators (PAs) is numerically investigated by direct numerical simulation in order to clarify the most effective location of actuator installation and to elucidate the mechanism of control effect. The ...

Amer Physical Soc2017

Optimal Control of Part Load Vortex Rope in Francis Turbines

François Avellan, François Gallaire, Simon Pasche

The mitigation of the precessing vortex core developing in the draft tube of Francis turbines operating under part load conditions is crucial to increase the operation flexibility of these hydraulic machines to balance the massive power production of inter ...

ASME2019

Viscous growth and rebound of a bubble near a rigid surface

François Gallaire, Giacomo Gallino

Motivated by the dynamics of microbubbles near catalytic surfaces in bubble-powered microrockets, we consider theoretically the growth of a free spherical bubble near a flat no-slip surface in a Stokes flow. The flow at the bubble surface is characterised ...

Cambridge University Press2018

Physics of Bubble-Propelled Microrockets

François Gallaire, Giacomo Gallino

A popular method to induce synthetic propulsion at the microscale is to use the forces created by surface-produced gas bubbles inside the asymmetric body of a catalytic swimmer (referred to in the literature as microrocket). Gas bubbles nucleate and grow w ...

2018

Effective stress jump across membranes

François Gallaire, Giuseppe Antonio Zampogna

A macroscopic condition to simulate the interaction between an incompressible fluid flow and a permeable micro-structured rigid surface (i.e. a thin membrane) has been developed using multiscale homogenization and matching asymptotic expansions between the ...

Cambridge University Press2020

Spatio-temporal stability of the Kármán vortex street and the effect of confinement

François Gallaire

The instability of the Kármán vortex street is revisited under a spatio-temporal perspective that allows the taking into account of the advection of the vortices by the external flow. We analyse a simplified point vortex model and show through numerical si ...

Cambridge University Press2016

On the effect of a penetrating recirculation region on the bifurcations of the flow past a permeable sphere

François Gallaire, Pier Giuseppe Ledda, Giuseppe Antonio Zampogna

We study the flow past a permeable sphere modeled using homogenization theory. The flow through the porous medium is described by the Darcy law, in which the permeability quantifies the resistance for the fluid to pass through the microstructure. A slip co ...

AIP Publishing2021

Weakly nonlinear versus semi-linear models of the nonlinear evolution of the centrifugal instability

François Gallaire, Eunok Yim

We carry out a weakly nonlinear analysis of the centrifugal instability for a columnar vortex in a rotating fluid, and compare the results to those of the semi-linear model derived empirically by Yim et al. (J. Fluid Mech., vol. 897, 2020, A34). The asympt ...

Cambridge University Press2023

Releasing long bubbles trapped in thin capillaries via tube centrifugation and inclination

Paul Edouard Etienne Dené, Valentin Hugo Buriasco, François Gallaire

In confined systems, the entrapment of a gas volume with an equivalent spherical diameter greater than the dimension of the channel can form extended bubbles that obstruct fluid circuits and compromise performance. Notably, in sealed vertical tubes, buoyan ...

Cambridge University Press2024

Manipulating flow separation: sensitivity of stagnation points, separatrix angles and recirculation area to steady actuation

François Gallaire, Edouard Boujo

A variational technique is used to derive analytical expressions for the sensitivity of several topological indicators of flow separation to steady actuation. Considering the boundary layer flow above a wall-mounted bump, the six following representative q ...

Royal Soc2014

Boundary elements method for microfluidic two-phase flows in shallow channels

François Gallaire, Mathias Nagel

In the following work we apply the boundary element method to two-phase flows in shallow microchannels, where one phase is dispersed and does not wet the channel walls. These kinds of flows are often encountered in microfluidic Lab-On-A-Chip devices and ch ...

Elsevier2015

Influence of the inlet velocity profile on the flow stability in a symmetric channel expansion

François Gallaire, Lorenzo Siconolfi

In a channel flow with a sudden expansion, whether for three-dimensional (3-D) pipe and channel flows, or for two-dimensional (2-D) channel flow, it is known that increasing the Reynolds number beyond a critical value induces a symmetry breaking Pitchfork ...

Cambridge University Press2020

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

François Gallaire, Francesco Viola, Alessandro Bongarzone

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

Energetic Macroscopic Representation of A Linear Reciprocating Compressor Model

Alfred Rufer, François Gallaire, Philippe Barrade, Mahbod Heidari

This article introduces the energetic macroscopic representation (EMR) as approach for the dynamic nonlinear modeling of a reciprocating air compressor. EMR has been introduced recently for research development in complex electromechanical systems and is b ...

Elsevier2015

Deformation of porous flexible strip in low and moderate Reynolds number flows

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

We present results from a combined experimental and numerical investigation of the fluid-structure interaction of cantilevered porous flexible strips, towed through a fluid bath. We characterize the steady-state deformation of the strips and their associat ...

AMER PHYSICAL SOC2020

Impinging planar jets: hysteretic behaviour and origin of the self-sustained oscillations

Philippe Renaud, François Gallaire, Arnaud Bertsch, Alessandro Bongarzone

The experimental and numerical investigation presented by Bertsch et al. (Phys. Rev. Fluids, vol. 5, 2020a, p. 054202) describes the self-sustained oscillations induced by the interaction of two impinging jets in microfluidic devices. While the oscillatory ...

Cambridge University Press2021

Effects of spanwise confinement on stratified shear instabilities

François Gallaire, Yves-Marie François Ducimetière

We consider the influence of transverse confinement on the instability properties of velocity and density distributions reminiscent of those pertaining to exchange flows in stratified inclined ducts, such as the recent experiment of Lefauve et al. [J. Flui ...

2021

Three-dimensional Rayleigh–Taylor instability under a unidirectional curved substrate

François Gallaire, Pierre-Thomas Paul Brun, Gioele Mariano Nicolò Balestra, Nicolas Igor Jacques Kofman

We investigate the Rayleigh–Taylor instability of a thin liquid film coated on the inside of a cylinder whose axis is orthogonal to gravity. We are interested in the effects of geometry on the instability, and contrast our results with the classical case o ...

Cambridge University Press2017

Stick-slip-to-stick transition of liquid oscillations in a U-shaped tube

François Gallaire, Alessandro Bongarzone

The nonlinear decay of oscillations of a liquid column in a U-shaped tube is investigated within the theoretical framework of the projection method formalized by Bongarzone et al. [Chaos 31, 123124 (2021)]. Starting from the full hydrodynamic system supple ...

Amer Physical Soc2024