# Laboratoire de Mécanique des Fluides et d’Acoustique - UMR 5509

LMFA - UMR 5509
Laboratoire de Mécanique des Fluides et d’Acoustique
Lyon
France

## Transport de particules

L’équipe appartient au réseau européen particle-based-cloud-modelling, et participe au projet IDEXLyon Breakthrough "Turbullet", qui réunit six laboratoires Lyonnais (physique, mécanique, mathématique, astro et géophysique).

Les approches concernant le mélange et la dispersion étant multiples, nous choisissons de nous concentrer sur des questions précises allant du point de vue lagrangien fondamental à la dispersion de particules réelles, éventuellement des bulles, des gouttelettes, ou plus généralement des écoulements diphasiques. On notera également des travaux récents sur les particules actives (en écoulements laminaires ou turbulents).

Voici un exemple de question à laquelle nous tentons de répondre :
nous étudions des particules anisotropes, objets de géométrie sphéroïdale, dans la continuité de nos travaux. L’originalité de l’approche réside dans la prise en compte des corrections inertielles (dues à l’inertie du fluide) dans les équations du mouvement de translation et de rotation des objets. L’étude a pour objectif l’application à la microphysique des nuages, les particules sphéroïdales modélisant des cristaux de glace.

Quelques publications associées à nos récents travaux :
2020

Article dans Phys. Rev. X (2020)

### Kolmogorovian active turbulence of a sparse assembly of interacting Marangoni surfers

Mickaël Bourgoin, Ronan Kervil, Cécile Cottin-Bizonne, Florence Raynal, Romain Volk & Christophe Ybert

Active matter, composed of self-propelled entities, forms a wide class of out-of-equilibrium systems that display striking collective behaviors, among which, the so-called active turbulence where (...)

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Article dans J. Fluid Mech. (2020)

### Importance of fluid inertia for the orientation of spheroids settling in turbulent flow

Muhammad Zubair Sheikh, Kristian Gustavsson, Diego Lopez, Emmanuel Lévêque, Bernhard Mehlig, Alain Pumir & Aurore Naso

How non-spherical particles orient as they settle in a flow has important practical implications in a number of scientific and engineering problems. In a quiescent fluid, a slowly settling (...)

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2019

Article dans New Journal of Physics (2019)

### Effect of fluid inertia on the orientation of a small prolate spheroid settling in turbulence

Kristian Gustavsson, Muhammad Zubair Sheikh, Diego Lopez, Aurore Naso, Alain Pumir and Bernard Mehlig

We study the angular dynamics of small non-spherical particles settling in a turbulent flow, such as ice crystals in clouds, aggregates of organic material in the oceans, or fibres settling in (...)

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2018

Article dans Comput. Fluids (2018)

### An improved multiscale Eulerian–Lagrangian method for simulation of atomization process

Davide Zuzio, Jean-Luc Estivalèzes & Bastien Di Pierro

The physics of atomization process involve many spatial scales, generating a wide variety of liquid inclusions of different sizes with large density and viscosity ratios between liquid and gas (...)

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Article dans J. Fluid Mech. (2018)

### The effective diffusivity of ordered and freely evolving bubbly suspensions

Aurore Loisy, Aurore Naso & Peter D. M. Spelt

We investigate the dispersion of a passive scalar such as the concentration of a chemical species, or temperature, in homogeneous bubbly suspensions, by determining an effective diffusivity (...)

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Article dans J. Fluid Mech. (2018)

### Collision rate of ice crystals with water droplets in turbulent flows

Aurore Naso, Jennifer Jucha, Emmanuel Lévêque & Alain Pumir

Riming, the process whereby ice crystals get coated by impacting supercooled liquid droplets, is one of the dominant processes leading to precipitation in mixed-phase clouds. How a settling (...)

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Article dans J. Fluid Mech. (2018)

### A note on Stokes’ problem in dense granular media using the $\mu(I)$-rheology

J. John Soundar Jerome & Bastien Di Pierro

The classical Stokes’ problem describing the fluid motion due to a steadily moving infinite wall is revisited in the context of dense granular flows of mono-dispersed beads using the recently (...)

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Article dans Int. J. Multiph. Flow (2018)

### Numerical analysis of the flapping mechanism for a two-phase coaxial jet

Nicolas Odier, Guillaume Balarac & Christophe Corre

A numerical study of a coaxial liquid jet sheared by an annular high-speed stream is performed at moderate density and velocity ratio between phases. The destabilization mechanism of the jet is (...)

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Article dans Eur. J. Mech. B-Fluids (2018)

### A flow-pattern map for phase separation using the Navier–Stokes–Cahn–Hilliard model

Aurore Naso & Lennon Ó Náraigh

We use the Navier–Stokes–Cahn–Hilliard model equations to simulate phase separation with flow. We study coarsening — the growth of extended domains wherein the binary mixture phase separates into its (...)

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Article dans Phys. Rev. Fluids (2018)

### Turbulence and turbulent pattern formation in a minimal model for active fluids

Martin James, Wouter J. T. Bos, and Michael Wilczek

Active matter systems display a fascinating range of dynamical states, including stationary patterns and turbulent phases. While the former can be tackled with methods from the field of pattern (...)

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Article dans J. Fluid Mech. (2018)

### Instability of pressure-driven gas–liquid two-layer channel flows in two and three dimensions

Lennon Ó Náraigh & Peter D. M. Spelt

We study unstable waves in gas–liquid two-layer channel flows driven by a pressure gradient, under stable stratification, not assumed to be set in motion impulsively. The basis of the study is (...)

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Article dans Phys. Rev. Fluids (2018)

### Settling and collision between small ice crystals in turbulent flows

Jennifer Jucha, Aurore Naso, Emmanuel Lévêque, and Alain Pumir

Ice crystals are present in a variety of clouds, at sufficiently low temperature. We consider here mixed-phase clouds which, at temperature ≳−20$^\circ$C, contain ice crystals, shaped approximately (...)

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2017

Article dans Phys. Rev. Fluids (2017)

### Interaction between a large buoyant bubble and turbulence

Aurore Loisy and Aurore Naso

The free rise of isolated, deformable, finite-size bubbles in otherwise homogeneous isotropic turbulence is investigated by direct numerical simulation. The Navier-Stokes equations are solved in (...)

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Article dans J. Fluid Mech. (2017)

### Buoyancy-driven bubbly flows : ordered and free rise at small and intermediate volume fraction

Aurore Loisy, Aurore Naso and Peter D. M. Spelt

Various expressions have been proposed previously for the rise velocity of gas bubbles in homogeneous steady bubbly flows, generally a monotonically decreasing function of the bubble volume (...)

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Article dans Phys. Rev. Fluids (2017)

### Directional change of fluid particles in two-dimensional turbulence and of football players

Benjamin Kadoch, Wouter J. T. Bos, and Kai Schneider

Multiscale directional statistics are investigated in two-dimensional incompressible turbulence. It is shown that the short-time behavior of the mean angle of directional change of fluid (...)

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Article dans Phys. Rev. Lett. (2017)

### Statistical Model for the Orientation of Nonspherical Particles Settling in Turbulence

K. Gustavsson, J. Jucha, A. Naso, E. Lévêque, A. Pumir, and B. Mehlig

The orientation of small anisotropic particles settling in a turbulent fluid determines some essential properties of the suspension. We show that the orientation distribution of small heavy (...)

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Article dans Eur. Phys. J. E (2017)

### Pressure dependence of the electrical transport in granular materials

Mathieu Creyssels, Claude Laroche, Éric Falcon, Bernard Castaing

We report on systematic measurements of the electrical resistance of one- and three-dimensional (1D and 3D) metallic and oxidized granular materials under uni-axial compression. Whatever the (...)

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2016

Article dans Flow Turbul. Combust. (2016)

### Acceleration statistics of finite-size particles in turbulent channel flow in the absence of gravity

Wenchao Yu, Ivana Vinkovic & Marc Buffat

The interaction between finite-size particles and turbulent channel flow in the absence of gravity is studied here by direct numerical simulation. The turbulent flow is resolved by an efficient (...)

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Article dans Europhys. Lett. (2016)

### Spread of consensus in self-organized groups of individuals : Hydrodynamics matters

Alessandro De Rosis, Emmanuel Lévêque, Francesco Ubertini & Sauro Succi

Nature routinely presents us with spectacular demonstrations of organization and orchestrated motion in living species. Efficient information transfer among the individuals is known to be (...)

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Article dans J. Therm. Sci. Eng. Appl. (2016)

### Active Insulation Technique Applied to the Experimental Analysis of a Thermodynamic Control System for Cryogenic Propellant Storage

Samuel Mer, Jean-Paul Thibault & Christophe Corre

A technological barrier for long-duration space missions using cryogenic propulsion is the control of the propellant tank self-pressurization (SP). Since the cryogenic propellant submitted to (...)

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Article dans J. Turbul. (2016)

### Finite-size particles in turbulent channel flow : quadrant analysis and acceleration statistics

Wenchao Yu, Ivana Vinkovic & Marc Buffat

The interaction between finite-size particles and turbulent channel flow in the absence of gravity is studied by direct numerical simulations (DNS). The study is motivated by DNS observations of (...)

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Article dans Cryogenics (2016)

### Optimal design of a thermodynamic vent system for cryogenic propellant storage

Samuel Mer, David Fernandez, Jean-Paul Thibault & Christophe Corre

Future operations in space exploration require to store cryogenic liquids for long duration. Residual heat loads, due to heat conduction in the launcher structure or solar radiation, induce (...)

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2015

Article dans J. Turbul. (2015)

### Collision rate for suspensions at large Stokes numbers – comparing Navier–Stokes and synthetic turbulence

Michel Voßkuhle, Alain Pumir, Emmanuel Lévêque & Michael Wilkinson

The use of simplified models of turbulent flows provides an appealing possibility to study the collision rate of turbulent suspensions, especially in conditions relevant to astrophysics, which (...)

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Article dans Phys. Rev. E (2015)

### Flow-parametric regulation of shear-driven phase separation in two and three dimensions

Lennon Ó Náraigh, Selma Shun & Aurore Naso

The Cahn-Hilliard equation with an externally prescribed chaotic shear flow is studied in two and three dimensions. The main goal is to compare and contrast the phase separation in two and three (...)

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Article dans Int. J. Multiph. Flow (2015)

### Numerical study of a flapping liquid sheet sheared by a high-speed stream

Nicolas Odier, Guillaume Balarac, Christophe Corre & Vincent Moureau

A numerical study of a liquid sheet sheared on both sides by a high-speed stream is performed in this work, at moderate density and velocity ratio between phases. Near the injection, an (...)

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2014

Article dans J. Fluid Mech. (2014)

### Prevalence of the sling effect for enhancing collision rates in turbulent suspensions

Michel Voßkuhle, Alain Pumir, Emmanuel Lévêque & Michael Wilkinson

Turbulence facilitates collisions between particles suspended in a turbulent flow. Two effects have been proposed that can enhance the collision rate at high turbulence intensities : ‘preferential (...)

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Article dans J. Fluid Mech. (2014)

### Linear instability, nonlinear instability and ligament dynamics in three-dimensional laminar two-layer liquid–liquid flows

Lennon Ó Náraigh, Prashant Valluri, David M. Scott, Iain Bethune & Peter D. M. Spelt

We consider the linear and nonlinear stability of two-phase density-matched but viscosity-contrasted fluids subject to laminar Poiseuille flow in a channel, paying particular attention to the (...)

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