Publications associées à Entrainement de bois flottant dans un déversoir a crête standard avec piliers: Influence des caractéristiques de bois flottant en probabilités de blocage

Noise-induced transitions past the onset of a steady symmetry-breaking bifurcation: The case of the sudden expansion

François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière

We consider fluid flows, governed by the Navier-Stokes equations, subject to a steady symmetry-breaking bifurcation and forced by a weak noise acting on a slow timescale. By generalizing the multiple-scale weakly nonlinear expansion technique employed in t ...

2024

Measurement and modelling of dynamic fluid saturation in carbon reinforcements

Véronique Michaud, Baris Çaglar, Helena Luisa Teixido Pedarros, Guillaume Clément Broggi

We propose a methodology to monitor the progressive saturation of a non-translucent unidirectional carbon fabric stack through its thickness by means of X-ray radiography and extract the dynamic saturation curves using image analysis. Four constant flow ra ...

2023

Visualization and modelling of dynamic flow in fibrous preforms for liquid composite molding

Helena Luisa Teixido Pedarros

Nowadays, Liquid Composite Molding techniques are often used to manufacture high quality fiber reinforced composite parts at a relatively low cost. These involve an infiltration process, in which a liquid resin is forced to ingress into a dry fibrous porou ...

EPFL2023

Three-dimensional micro-CT images of UV-frozen flow fronts recorded at different flow regimes

Véronique Michaud, Jacobus Gerardus Rudolph Staal

Segmented micro-CT images of flow fronts produced by UV-flow freezing. Front morphologies correspond to capilary-dominated, equilibrated and viscous-dominated flow regimes. ...

Zenodo2023

Numerical analysis of apparatus-induced dispersion for density-dependent solute transport in porous media

David Andrew Barry, Hong Zhang

The effects of apparatus-induced dispersion on nonuniform, density-dependent flow in a cylindrical soil column were investigated using a finite-element model. To validate the model, the results with an analytical solution and laboratory column test data we ...

2023

Dynamic environmental flows using hydrodynamic-based solutions for sustainable hydropower

Giovanni De Cesare, Paolo Perona

Water diversions from rivers and torrents for anthropic uses of the resource alter the natural flow regime. As a measure, environmental flows have been prescribed and often are enforced by law to follow policies (e.g., minimal flow, proportional redistribu ...

CRC Press/Balkema2023

Effect of blocked driftwood on the hydraulic performance of a gated standard weir

Giovanni De Cesare, Michael Pfister, Loïc Bénet

Driftwood belongs to riverine ecosystems and is stored and transported in every natural stream. Hydraulic structures built in streams typically alter the flow characteristics and might consequently get in conflict with driftwood. The latter can get trapped ...

International Association for Hydro-Environment Engineering and Research (IAHR)2022

Effects of velocity-dependent apparent toughness on the pre- and post-shut-in growth of a hydraulic fracture

Dong Liu, Guanyi Lu

We investigate the growth of a plane-strain/radial hydraulic fracture in an infinite impermeable medium driven by a constant injection rate assuming that the apparent toughness scales with the decreasing fracture growth rate in a power-law relation. The vi ...

ELSEVIER SCI LTD2022

Weakly nonlinear evolution of stochastically driven non-normal systems

François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière

We consider nonlinear dynamical systems driven by stochastic forcing. It has been largely evidenced in the literature that the linear response of non-normal systems (e.g. fluid flows) may exhibit a large variance amplification, even in a linearly stable re ...

Cambridge University Press2022

Flow pattern observations and flow pattern map for adiabatic two-phase flow of carbon dioxide in vertical upward and downward direction

Jürg Alexander Schiffmann, Rémi Revellin, David Schmid

A test facility to investigate flow pattern transitions of vertical two-phase flow of CO2 has been built within the scope of the high-luminosity detector upgrades at the European Organization for Nuclear Research (CERN). Adiabatic flow pattern observations ...

2022

Experimental quantification of unsteady leading-edge flow separation

Karen Ann J Mulleners, Julien Dominique Claude Deparday

We propose here a method to experimentally quantify unsteady leading-edge flow separation on aerofoils with finite thickness. The methodology relies on the computation of a leading-edge suction parameter based on measured values of the partial circulation ...

Cambridge University Press2022

Automated flow control of a multi-lane swimming chamber for small fishes indicates species-specific sensitivity to experimental protocols

In fishes, swimming performance is considered an important metric to measure fitness, dispersal and migratory abilities. The swimming performance of individual larval fishes is often integrated into models to make inferences on how environmental parameters ...

2021

Blockage Probability Modeling of Large Wood at Reservoir Spillways With Piers

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos, Michael Pfister, Paloma Furlan

Large wood increases the morphological and hydraulic complexity of rivers, yet it may block and modify the flood discharge capacity of hydraulic structures. To assess the related risk, blockage probability estimation for hydraulic structures such as reserv ...

2021

Reservoir Level Rise under Extreme Driftwood Blockage at Ogee Crest

Giovanni De Cesare, Michael Pfister, Loïc Bénet

Dams are civil structures essential to modern civilization. However, they can be a threat if not properly designed and operated. A particular risk that potentially can lead to dam failure is the blocking of the spillway inlet with driftwood or debris. This ...

2021

Quantifying the transition of impact mechanisms of geophysical flows against flexible barrier

Xingyue Li

Flexible barriers have been increasingly used worldwide for mitigating natural hazards involving various geophysical flows. The analysis and design of flexible barriers need to distinguish two major impact mechanisms, runup and pile-up, which remain poorly ...

ELSEVIER2021

Stilling Basin Performance Downstream of Stepped Spillways

Ivan Stojnic

Advances in dam construction techniques have significantly increased the number of implemented stepped spillways worldwide. A key hydraulic feature of a stepped chute, compared to a smooth chute, is the enhanced energy dissipation resulting in a reduced re ...

EPFL2020

Forces on buildings with openings and orientation in a steady post-tsunami free-surface flow

Anton Schleiss, Michael Pfister, Davide Wüthrich

Steady free-surface flows around buildings occurring during flood or tsunami events can produce major damages and a quantification of the post-peak forces is essential for safety and resilience of coastal structures. The loading process is highly affected ...

2020

Scanning PIV of turbulent flows over and through rough porous beds using refractive index matching

Christophe Ancey, Gauthier Paul Daniel Marie Rousseau

This paper presents image velocimetry measurements on turbulent flows adjacent to a permeable bed made of randomly packed glass particles. For measuring flow velocities inside the bed, the refractive index of the glass particles was matched with that of th ...

SPRINGER2020

Numerical investigation on water exchange of shale samples

Alessio Ferrari, Sara Incollingo

Interest in the hydraulic and mechanical characterization of shales has grown in recent years, because of their application in the context of energy geotechnics. In the frame of nuclear waste disposal shales are considered as host formations for the placem ...

E D P SCIENCES2020

Numerical Simulations of an Innovative Water Stirring Device for Fine Sediment Release: The Case Study of the Future Trift Reservoir

Pedro Filipe De Almeida Manso, Azin Amini, Anass Chraibi

Reservoir sedimentation and consequently lack of storage volume and perturbation of the operation of intakes and bottom outlet is a key challenge affecting both hydropower production as well as dam safety and flood management. In the framework of a peer-re ...

Springer2020