Laboratoire de Mécanique des Fluides et d'Acoustique - UMR 5509

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


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Accueil > Équipes > Turbulence & Instabilités

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 : 

Diffusiophoresis, Batchelor scale and effective Péclet numbers

Article dans J. Fluid. Mech. (2019)

Diffusiophoresis, Batchelor scale and effective Péclet numbers

Florence Raynal & Romain Volk

We study the joint mixing of colloids and salt released together in a stagnation point or in a globally chaotic flow. In the presence of salt inhomogeneities, the mixing time is strongly modified (...)

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

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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Observing mesospheric turbulence with specular meteor radars : A novel method for estimating second order statistics of wind velocity

Article dans Earth and Space Science (2019)

Observing mesospheric turbulence with specular meteor radars : A novel method for estimating second order statistics of wind velocity

J. Vierinen, J. L. Chau, H. Charuvil, J.M.Urco, M. Clahsen, V. Avsarkisov, R. Marino, and R. Volz

There are few observational techniques for measuring the distribution of kinetic energy within the mesosphere with a wide range of spatial and temporal scales. This study describes a method for (...)

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The low-frequency break observed in the slow solar wind magnetic spectra

Article dans Astronomy & Astrophysics (2019)

The low-frequency break observed in the slow solar wind magnetic spectra

Roberto Bruno, Daniele Telloni, Luca Sorriso-Valvo, Raffaele Marino, Rossana De Marco, Raffaela D’Amicis

Fluctuations of solar wind magnetic field and plasma parameters exhibit a typical turbulence power spectrum with a spectral index ranging between ∼ 5/3 and ∼ 3/2. In particular, at 1 AU, the (...)

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The effects of solid barriers and blocks on the propagation of smoke within longitudinally ventilated tunnels

Article dans Building and Environment (2019)

The effects of solid barriers and blocks on the propagation of smoke within longitudinally ventilated tunnels

Fateh Chaabat, Mathieu Creyssels, A. Mos, J. Wingrave, Horacio Correia, Massimo Marro & Pietro Salizzoni

A series of experiments were conducted to investigate the effect of solid barriers, placed at the tunnel ceiling, on the behaviour of smoke in fire events within longitudinally ventilated (...)

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Control of light gas releases in ventilated tunnels

Article dans J. Fluid. Mech. (2019)

Control of light gas releases in ventilated tunnels

Lei Jiang, Mathieu Creyssels, Gary R. Hunt & Pietro Salizzoni

The release of buoyant harmful gases within enclosed spaces, such as tunnels and corridors, may engender specific health, industrial and transportation risks. For safety, a simple ventilation (...)

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Refinement of the logarithmic law of the wall

Article dans Phys. Rev. Fluids (2019)

Refinement of the logarithmic law of the wall

Faouzi Laadhari

Available direct numerical simulation of turbulent channel flow at moderately high Reynolds numbers data show that the logarithmic diagnostic function is a linearly decreasing function of the (...)

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Particle transport induced by internal wave beam streaming in lateral boundary layers

Article dans J. Fluid. Mech. (2019)

Particle transport induced by internal wave beam streaming in lateral boundary layers

E. Horne, F. Beckebanze, D. Micard, P. Odier, L. R. M. Maas & S. Joubaud

Quantifying the physical mechanisms responsible for the transport of sediments, nutrients and pollutants in the abyssal sea is a long-standing problem, with internal waves regularly invoked as (...)

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Asymmetry of vertical buoyancy gradient in stratified turbulence

Article dans J. Fluid Mech. (2019)

Asymmetry of vertical buoyancy gradient in stratified turbulence

Andrea Maffioli

We consider the asymmetry of the buoyancy field in the vertical direction in stratified turbulence. While this asymmetry is known, its causes are not well understood, and it has not been (...)

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Passive scalar mixing in modulated turbulence

Article dans Fluid Dyn. Res. (2019)

Passive scalar mixing in modulated turbulence

Yuyao Yang, Robert Chahine, Robert Rubinstein & Wouter JT Bos

We investigate the mixing of a passive scalar in an isotropic turbulent flow in the presence of a time-periodic forcing. The results corroborate recent analytical predictions on the frequency (...)

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Theoretical and numerical study on high frequency vibrational convection : Influence of the vibration direction on the flow structure

Article dans Phys. Fluids (2019)

Theoretical and numerical study on high frequency vibrational convection : Influence of the vibration direction on the flow structure

Samia Bouarab, Faiza Mokhtari, Slim Kaddeche, Daniel Henry, Valéry Botton & Abdessamed Medelfef

Thermal convection induced simultaneously by horizontal temperature gradient and vibration in a rectangular cavity filled with molten silicon is investigated numerically and theoretically. The (...)

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Harmonic to subharmonic transition of the Faraday instability in miscible fluids

Article dans Phys. Rev. Fluids (2019)

Harmonic to subharmonic transition of the Faraday instability in miscible fluids

Antoine Briard, Benoît-Joseph Gréa & Louis Gostiaux

When a stable stratification between two miscible fluids is excited by a vertical and periodic forcing, a turbulent mixing zone can develop, triggered by the Faraday instability. The mixing zone (...)

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Transition to chaos in an acoustically driven cavity flow

Article dans Phys. Rev. Fluids (2019)

Transition to chaos in an acoustically driven cavity flow

Gaby Launay, Tristan Cambonie, Daniel Henry, Alban Pothérat & Valéry Botton

We consider the unsteady regimes of an acoustically driven jet that forces a recirculating flow through successive reflections on the walls of a square cavity. The specific questions addressed (...)

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