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

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

## Turbulence & Instabilités

Responsable : Florence Raynal

Les activités de l’équipe, à caractère plutôt fondamentales, concernent l’analyse des instabilités hydrodynamiques, la transition laminaire/turbulence, les écoulements turbulents, et les écoulements à petite échelle.

Les actualités de T&I :

### Posters doctorants 2A

Nos étudiants doctorants en 2ème année ont réalisé des posters didactiques pendant le confinement. Les consignes et le modèle sont donnés ici.
À défaut de pouvoir les accrocher sur les murs du labo pour (...)

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Article dans J. Fluid. Mech. (2020)

### Numerical study of extreme mechanical force exerted by a turbulent flow on a bluff body by direct and rare-event sampling techniques

Thibault Lestang, Freddy Bouchet & Emmanuel Lévêque

This study investigates, by means of numerical simulations, extreme mechanical force exerted by a turbulent flow impinging on a bluff body, and examines the relevance of two distinct rare-event (...)

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Article dans Atmosphere (2020)

### Partitioning Waves and Eddies in Stably Stratified Turbulence

Henri Lam, Alexandre Delache & Fabien Godeferd

We consider the separation of motion related to internal gravity waves and eddy dynamics in stably stratified flows obtained by direct numerical simulations. The waves’ dispersion relation links (...)

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Article dans J. Fluid. Mech. (2020)

### Analysis of turbulence characteristics in a temporal dense gas compressible mixing layer using direct numerical simulation

Aurélien Vadrot, Alexis Giauque & Christophe Corre

This study investigates the effects of a Bethe–Zel’dovich–Thompson (BZT) dense gas (FC-70) on the development of a turbulent compressible mixing layer at a convective Mach number $M_c=1.1$. (...)

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Article dans Journal of Turbulence (2020)

### Staircase scaling of short-time energy transfer in turbulence

Le Fang, T. Wu & Wouter Bos

It is illustrated that a sharply truncated initial kinetic energy spectrum evolves to a staircase-shaped spectrum at short times. This effect is directly associated with the triadic nature of the (...)

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Article dans Phys. Rev. E (2020)

### Efficiency of laminar and turbulent mixing in wall-bounded flows

Benjamin Kadoch, Wouter Bos & Kai Schneider

A turbulent flow mixes in general more rapidly a passive scalar than a laminar flow does. From an energetic point of view, for statistically homogeneous or periodic flows, the laminar regime is (...)

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Article dans Phys. Rev. Fluids (2020)

### Scaling laws in axisymmetric magnetohydrodynamic duct flows

Alexandre Poyé, Olivier Agullo, Nicolas Plihon, Wouter Bos, Victor Desangles & Guillaume Bousselin

We report on a numerical study of axisymmetric flow of liquid metal in a circular duct with a rectangular cross section. The flow is forced through the combination of an axial magnetic field and (...)

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Article dans Journal of Turbulence (2020)

### Direct numerical simulations of forced homogeneous isotropic turbulence in a dense gas

Alexis Giauque, Christophe Corre & Aurélien Vadrot

Direct Numerical Simulations (DNS) of forced homogeneous isotropic turbulence in a dense gas (FC-70), accurately described by a complex EoS, are computed for a turbulent Mach number of 0.8. In a (...)

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Article dans Atmosphere (2020)

### Nonlinear Effects on the Precessional Instability in Magnetized Turbulence

Abdelaziz Salhi, Amor Khlifi & Claude Cambon

By means of direct numerical simulations (DNS), we study the impact of an imposed uniform magnetic field on precessing magnetohydrodynamic homogeneous turbulence with a unit magnetic Prandtl (...)

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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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Article dans J. Fluid. Mech. (2020)

### The turbulent Faraday instability in miscible fluids

Antoine Briard, Louis Gostiaux & Benoît-Joseph Gréa

Experiments of a turbulent mixing zone created by the Faraday instability at the statically stable interface between salt and fresh water are presented. The two-layer system, contained in a (...)

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