Publications associées à Ressaut hydraulique

Self-sustained dynamics and forced resonant oscillations in flows: cross-junction jets and sloshing liquids

In engineering, oscillatory instabilities and resonances are often considered undesirable flow features and measures are taken to avoid them. This may include avoiding certain parametric regions or implementing control and mitigation strategies. However, t ...

EPFL2023

Moored observations of turbulent mixing events in deep Lake Garda, Italy

Sebastiano Piccolroaz, Marco Toffolon

Deep water circulation and mixing processes are responsible for the transport of matter, nutrients and pollutants in deep lakes. Nevertheless, detailed continuous observations are rarely available. To overcome some of these deficiencies and with the aim of ...

2021

Mechanical and hydraulic transport properties of transverse-isotropic Gneiss deformed under deep reservoir stress and pressure conditions

Marie Estelle Solange Violay, Mateo Alejandro Acosta

In central Europe, many geo-energy reservoirs have revealed to be hosted in transverse isotropic crystalline rock, where the rock's mechanical and hydraulic transport properties are poorly constrained. Here, we performed triaxial experiments on Cresciano G ...

2020

Extreme Hydrodynamic impact onto buildings

Davide Wüthrich

Dam failures, impulse waves, tsunamis and storm surges are disasters that challenge humanity, often leading to massive casualties and important economic losses. These events generate highly unsteady flow conditions in the form of surges or turbulent bores, ...

EPFL2018

Experimental Study of Tsunami-Like Waves Generated with a Vertical Release Technique on Dry and Wet Beds

Anton Schleiss, Michael Pfister, Davide Wüthrich, Ioan Nistor

Tsunamis, impulse waves, and dam failures are disasters that challenge humanity, often leading to massive casualties and extreme economic losses. The highly unsteady flow conditions generated by such events are often in the form of turbulent bores. The pur ...

2018

Nuclear Quantum Effects in Water Reorientation and Hydrogen-Bond Dynamics

David Mark Wilkins

We combine classical and ring polymer molecular dynamics simulations with the molecular jump model to provide a molecular description of the nuclear quantum effects (NQEs) on water reorientation and hydrogen-bond dynamics in liquid H2O and D2O. We show tha ...

Amer Chemical Soc2017

Characteristics of solitary waves on a falling liquid film sheared by a turbulent counter-current gas flow

Nicolas Igor Jacques Kofman

We report an experimental investigation of a falling water film sheared by a turbulent counter-current air flow in an inclined rectangular channel. Film thickness and wave velocity measurements associated with visual observation are conducted to study the ...

Elsevier2017

Pressure-dependent elastic and transport properties of porous and permeable rocks: Microstructural control

Lucas Xan Pimienta, Christian David

Although several studies aimed at linking electrical and hydraulic transport properties in rocks, the existing models remain at most incomplete. Based on this observation, in addition to the transport properties, this contribution investigates the pressure ...

Amer Geophysical Union2017

Experimental investigation of the local wave speed in a draft tube with cavitation vortex rope

François Avellan, Christophe Nicolet, Arthur Tristan Favrel, Christian Landry, Andres Müller, Keita Yamamoto

Hydraulic machines operating in a wider range are subjected to cavitation developments inducing undesirable pressure pulsations which could lead to potential instability of the power plant. The occurrence of pulsating cavitation volumes in the runner and t ...

IOP Publishing Ltd2014

Experimental investigation of the local wave speed in a draft tube with cavitation vortex rope

François Avellan, Christophe Nicolet, Arthur Tristan Favrel, Christian Landry, Keita Yamamoto

Hydraulic machines operating in a wider range are subjected to cavitation developments inducing undesirable pressure pulsations which could lead to potential instability of the power plant. The occurrence of pulsating cavitation volumes in the runner and t ...

Iop Publishing Ltd2014

Elasto-Dynamic Behavior of a Two-Dimensional Square Lattice With Entrained Fluid II: Microstructural and Homogenized Models

Alessandro Spadoni, Vladimir Dorodnitsyn

This paper presents a detailed study of the pressure waves and effective mechanical properties of a closed-cell cellular solid with entrained fluid. Plane-harmonic-waves are analyzed in a periodic square with a finite-element model of a representative-volu ...

Asme2014

Hydraulic design of the diaphragm’s orifice at the entrance of the surge shaft of FMHL pumped-storage power plant

Giovanni De Cesare, Christophe Nicolet, Fadi Hachem, Rafael Xavier Meriade Duarte

The surge tank located at the upstream head of penstocks and shafts of hydropower plants is an effective measure to protect the headrace tunnels against high pressure fluctuations. It reflects the transient pressure waves that are generated by the variatio ...

TPU2013

Shear velocity estimates in rough-bed open-channel flow

Ulrich Lemmin, Fereshteh Bagherimiyab Hunkeler

Shear velocity u(*) is an important parameter in geophysical flows, in particular with respect to sediment transport dynamics. In this study, we investigate the feasibility of applying five standard methods [the logarithmic mean velocity profile, the Reyno ...

Wiley-Blackwell2013

Dynamic pressure distribution around a fixed confined block impacted by plunging and aerated water jets

Anton Schleiss, Rafael Xavier Meriade Duarte

The scour process created by the impingement of high-velocity water jets on fissured rock is the result of complex physical phenomena. Of great importance are the jet development during the trajectory through the atmosphere, the diffusion process inside th ...

TUP2013

Secondary Currents and Corresponding Surface Velocity Patterns in a Turbulent Open-Channel Flow over a Rough Bed

Ulrich Lemmin, Ismail Albayrak

River and open-channel flows present complex three-dimensional (3D) structures in the water column and on the surface as a result of the existence of secondary currents driven by either centrifugal force or turbulence. This paper experimentally investigate ...

2011

Wave-induced watertable fluctuations, sediment transport and beach profile change: Modeling and comparison with large-scale laboratory experiments

David Andrew Barry, Alessandro Brovelli, Roham Bakhtyar

Coastal groundwater systems can have a considerable impact on sediment transport and foreshore evolution in the surf and swash zones. Process-based modeling of wave motion on a permeable beach taking into account wave-aquifer interactions was conducted to ...

Elsevier2011

OrbShake Bioreactors for Mammalian Cell Cultures : Engineering and Scale-up

Stéphanie Tissot

Most of the biopharmaceuticals nowadays are produced by animal cells. The worldwide demand for a specific group of biopharmaceuticals, the monoclonal antibodies (mAbs), has significantly increased this last decade. The mAbs are used as therapeutics in part ...

EPFL2011

Improving the accuracy of four-receiver acoustic Doppler velocimeter (ADV) measurements in turbulent boundary layer flows

Ulrich Lemmin, Fereshteh Bagherimiyab Hunkeler

Acoustic Doppler instrument measurements suffer from random spikes and Doppler noise. Using a four-receiver ADV (acoustic Doppler velocimeter; Vectrino manufactured by Nortek) that allows recording beam velocities, we combine a spike-removal procedure on t ...

Association for the Sciences of Limnology and Oceanography (ASLO)2010

An experimental study of coherent structures, secondary currents and surface boils and their interrelation in open-channel flow

Ismail Albayrak

River and open-channel flows are free surface boundary layer flows with complex 3D, large-scale, turbulent structures. The study of 2D and 3D large-scale turbulent flow structures is a great challenge for physicists, mathematicians and engineers from such ...

EPFL2008

Redistribution of velocity and bed-shear stress in straight and curved open channels by means of a bubble screen: Laboratory experiments

Koen Blanckaert

Open-channel beds show variations in the transverse direction due to the interaction between downstream flow, cross-stream flow, and bed topography, which may reduce the navigable width or endanger the foundations of structures. The reported preliminary la ...

2008