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Concept

Flottabilité

Publications associées (19)

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

Laterally unconfined neutral or negative buoyancy inflow into a quiescent ambient over sloping bottom

Haoran Shi

This work studies the nearshore hydrodynamics of a shallow turbulent flow entering a laterally unconfined quiescent ambient with a sloping bottom boundary. Examples of such flow are neutrally buoyant ebb tidal jets and hyperpycnal river plumes entering ope ...

EPFL2023

Propagation of planar three-dimensional buoyant hydraulic fractures

Andreas Möri

Hydraulic fractures are driven by an internal fluid pressure exceeding the minimum compressive stress, propagating in a direction perpendicular to the latter. This class of tensile fractures has gained interest over the last fifty years due to the developm ...

EPFL2023

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

Convection of snow: when and why does it happen?

Michael Lehning, Mahdi Jafari

Convection of water vapor in snowpacks is supposed to have a major impact on snow density and microstructure profiles with strong implications for the thermal regime and snow stability. However, the process has never been directly measured and only recentl ...

FRONTIERS MEDIA SA2023

Interactions of Cavitation Bubbles with Deformable Interfaces

Armand Baptiste Sieber

Cavitation is a topic that has long been of interest due to the large and growing range of applications associated with it. This is mainly because the collapse of cavitation bubbles releases a considerable amount of energy into the surrounding environment. ...

EPFL2023

Arrest Mechanisms of Buoyant Hydraulic Fractures

Brice Tanguy Alphonse Lecampion, Carlo Peruzzo, Andreas Möri, Dmitriy Garagash

Hydraulic fracturing (HF) treatments can form widespread fractures. Understanding their containment at depth is critical, given the positive buoyancy contrast between the fracturing fluid and the surrounding rock, promoting upward growth. We study arrest m ...

American Rock Mechanics Association (ARMA), OnePetro2023

Unconfined Plunging of a Hyperpycnal River Plume Over a Sloping Bed and Its Lateral Spreading: Laboratory Experiments and Numerical Modeling

David Andrew Barry, Koen Blanckaert, Ulrich Lemmin, Haoran Shi

Hyperpycnal (negatively buoyant) river inflow into lakes and oceans often develops three-dimensional (3D) plunging flow patterns when laterally unconfined. To determine the 3D flow pattern characteristics, laboratory experiments of laterally unconfined plu ...

American Geophysical Union2022

Accurate buoyancy and drag force models to predict particle segregation in vibrofluidized beds

Mehrdad Kiani Oshtorjani

The segregation of large intruders in an agitated granular system is of high practical relevance, yet the accurate modeling of the segregation (lift) force is challenging as a general formulation of a granular equivalent of a buoyancy force remains elusive ...

AMER PHYSICAL SOC2021

Hydrodynamic dead zone in multiphase geophysical flows impacting a rigid obstacle

Xingyue Li

When a gravity-driven solid-fluid mixture, such as those in geophysical flows, hits a wall-like rigid obstacle, a metastable jammed zone called hydrodynamic dead zone (HDZ) may emerge. The unjammed-jammed transition of HDZ, controlled by the intricate inte ...

2021

Continuously-fed density currents over impermeable and porous substrates

Sara Venuleo

Gravity currents are buoyancy-driven flows having a significant impact on the environment and human life. They can be observed in a vast range of natural and anthropogenic scenarios, such as seawater and freshwater, the atmosphere, or industrial processes. ...

EPFL2020

Propagation of fluid driven fractures in transversely isotropic material

Fatima-Ezzahra Moukhtari

The propagation of fluid driven fractures is used in a number of industrial applications (well stimulation of unconventional reservoirs, development of deep geothermal systems) but also occurs naturally (magmatic dyke intrusion). While the mechanics of hyd ...

EPFL2020

Device for measuring a force exerted on an object

Simon Nessim Henein, Charles Baur, Mohammad Hussein Kahrobaiyan, Mohamed Gamal Abdelrahman Ahmed Zanaty

The present invention relates to a device for measuring a contact force exerted by an object on a probe comprising a lever and said probe for contacting the object. The lever is pivotably coupled to a body by coupling means. The device comprising a fixed f ...

2020

Structure of a dense release produced by varying initial conditions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan

Buoyancy driven flows such as gravity currents, present in nature and human made applications, are conveyors of particles or dissolved substances for long distances with clear implications for the environment. This transport depends on the triggering condi ...

2018

Understanding the destabilizing role for surface tension in planar shear flows in terms of wave interaction

François Gallaire

Both surface tension and buoyancy force in stable stratification act to restore perturbed interfaces back to their initial positions. Hence, both are intuitively considered as stabilizing agents. Nevertheless, the Taylor-Caulfield instability is a countere ...

Amer Physical Soc2017

Adapting tilt corrections and the governing flow equations for steep, fully three-dimensional, mountainous terrain

Marc Parlange, Wolf Hendrik Huwald, Eric Richard Pardyjak, Holly Jayne Oldroyd

In recent studies of atmospheric turbulent surface exchange in complex terrain, questions arise concerning velocity-sensor tilt corrections and the governing flow equations for coordinate systems aligned with steep slopes. The standard planar-fit method, a ...

2016

Surface Turbulence on Bores and Surges propagating on Smooth and Rough Beds

Anton Schleiss, Pedro Filipe De Almeida Manso, Michael Pfister, Davide Wüthrich

Hydrodynamic waves are characterised by unsteady, highly turbulent and irregular behaviours. In nature, such phenomena can be observed in dam breaks, impulse waves and tsunamis. Both wet bed bores and dry bed surges were experimentally reproduced on smooth ...

2016

ALE/finite element modeling of an unconfined bubble plume in periodic domain: bubble shape and oscillation analysis

John Richard Thome, Gustavo Rabello Dos Anjos

This paper introduces a numerical model developed based upon the arbitrary Lagrangian-Eulerian/finite element scheme to analyze bubble plumes in a periodic domain. A spherical air bubble is immersed into a large pool of quiescent water to act as an unconfi ...

Springer Heidelberg2015

Influence of atmospheric stability on wind-turbine wakes: A large-eddy simulation study

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation is combined with a turbine model to investigate the influence of atmospheric thermal stability on wind-turbine wakes. The simulation results show that atmospheric stability has a significant effect on the spatial distri ...

American Institute of Physics2015