Publications associées à Temporal evolution of bedload in a steep channel over a long duration experiment

Stochastic Simulations and Machine Learning Modeling to Predict Bedload Transport and Bed Topography

In computational hydraulics models, predicting bed topography and bedload transport with sufficient accuracy remains a significant challenge. An accurate assessment of a river's sediment transport rate necessitates a prior understanding of its bed topograp ...

EPFL2024

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

Inversing the actuation cycle of dielectric elastomer actuators for a facial prosthesis

Paolo Germano, Yves Perriard, Yoan René Cyrille Civet, Alexis Boegli, Thomas Guillaume Martinez, Stefania Maria Aliki Konstantinidi, Quentin Philippe Mario De Menech

Dielectric Elastomer Actuators (DEAs) are a type of smart material described as compliant capacitors. They show impressive performances as soft actuators, such as a high strain and fast response. Nonetheless, replicating natural muscle function with DEAs h ...

Society of Photo-Optical Instrumentation Engineers (SPIE)2024

DEMO toroidal field coil fast discharge unit integration studies

Roberto Guarino, Alberto Ferro

The Fast Discharge Units (FDUs) of the Superconducting (SC) Toroidal Field (TF) coils in the European demonstration fusion power plant DEMO warrant the machine integrity over its full lifetime against severe failure events, such as SC coil quenches or any ...

Elsevier Science Sa2024

Clogging of riverbed substrates by fine sediment

Romain Maxime Dubuis

Riverbeds represent the habitat of numerous aquatic species. Exchanges between the groundwater, the hyporheic zone and the surface flow are also essential for river ecosystems. Fine sediment transported by rivers deposits inside or on top of the bed and mo ...

EPFL2023

Hydromorphological assessment of sediment augmentation measures in gravel-bed rivers

Christian Mörtl

In the riverine environment, the riverscape, sediment and flow regime are essential drivers for natural habitat dynamics. Today, most water courses in Europe are regulated, and their natural dynamics are impaired. Flood releases coupled with the artificial ...

EPFL2023

Reduction of riverbed clogging related to sediment flushing

Giovanni De Cesare, Romain Maxime Dubuis

The ecological effects of dams on sediment and river flow have been subject to an increasing attention, leading to the implementation of mitigation measures such as environmental flow release and sediment replenishment. However, fine sediment dynamics have ...

CRC Press/Balkema2023

The clogging of riverbeds: A review of the physical processes

Giovanni De Cesare, Romain Maxime Dubuis

Fine sediment represents an important part of the solid flux of rivers. Due to the size of these particles, they are often transported as suspended load. They gradually fill the pores of the substrate forming the hyporheic zone or cover the substrate by se ...

2023

Influence of the shear stress on fine sediment exchanges with the substrate using UVP measurements

Giovanni De Cesare, Romain Maxime Dubuis

The dynamic of fine sediment in rivers is closely related to the interactions between fine particles, the riverbed and the flow conditions. The accumulation of fine sediment in the riverbed reduces vertical water exchanges and can have detrimental effects ...

2023

Characterization of Thruster-Induced Turbulence for Fine Sediment Suspension

Giovanni De Cesare, Azin Amini, Montana Marshall, Andre Luis Stakowian

Reservoir sedimentation is a key challenge for storage sustainability because it causes volume loss, affecting hydropower production capacity, dam safety, and flood management. A preliminary EPFL study proposed and studied an innovative device (called SEDM ...

2023

Experimental modeling of fine sediment routing: SEDMIX device with thrusters

Giovanni De Cesare, Azin Amini, Montana Marshall

Reservoir sedimentation is a key challenge for storage sustainability because it causes volume loss, affecting hydropower production capacity, dam safety, and flood management. A preliminary EPFL study proposed and studied an innovative device (called SEDM ...

CRC Press/Balkema2023

Ultrasonic sediment flux profiling with ACVP Technology: application to sediment-laden Boundary Layer flows

Giovanni De Cesare, David Hurther

Sediment transport in geophysical boundary layer flows has relevance to a broad spectrum of sciences ranging from the physical and chemical, to the biological, ecological and geological. Advances in sediment transport modelling and prediction strongly suff ...

2023

Enhancing Flood Resilience: Sediment Management in Le Bez Torrent

Giovanni De Cesare, Azin Amini, Romain Nathan Hippolyte Merlin Van Mol

In the canton of Bern, Switzerland, the “Le Bez” torrent is known for its flash floods, causing sediment and wood debris buildup in Villeret village settled on the alluvial fan. To mitigate this issue, a sediment/wood trap system is being implemented upstr ...

Swiss Academy of Sciences (SCNAT)2023

Experimental characterization of root-reinforced riparian sediment deposits in a restored and widened river course

Giovanni De Cesare, Paolo Perona

The Arbogne River is located mainly in the Swiss canton of Fribourg. The River was meandering through the plane at a very low gradient and several exceptional historic floods with large sediment accumulation are mentioned. After important river training wo ...

2023

Influence of channel geomorphic units on bedload transport and river morphology during low‐magnitude bed‐forming floods coupled with sediment augmentation

Giovanni De Cesare, Severin Stähly, Christian Mörtl, Robin Schroff

In this study, we map different types of channel geomorphic units in a sediment-starved, residual-flow reach before and after an artificial flood. Bedload particles of a previous sediment augmentation measure are tracked with passive integrated transponder ...

2023

Limits between surface and inner clogging of riverbed by fine sediment

Giovanni De Cesare, Romain Maxime Dubuis

The deposition of fine sediment on top of the riverbed affects the reproduction of spawning fishes and some species of benthos. The clogging of the substrate resulting from this deposition is a well-known issue in rivers affected by anthropogenic activity ...

2023

Scaling behavior of bedload transport: what if Bagnold was right?

Christophe Ancey

There is a paradox in the relationship between bedload transport rates and flow variables: laboratory and field studies have reported on how bedload transport rates depend on flow variables through a power law, but none of the empirical laws fitted to the ...

2023

Continuous monitoring of morphological changes from sediment augmentation by field measurements and flume experiments

Giovanni De Cesare, Christian Mörtl

In this study, we present results from continuous field monitoring and a flume ex-periment of a sediment augmentation measure in a residual flow reach of the Swiss midlands. A straight morphological channel with fixed bed material was constructed to repres ...

2023

Small-scale dynamo with finite correlation times

Jennifer Waltraud Schober

Fluctuation dynamos occur in most turbulent plasmas in astrophysics and are the prime candidates for amplifying and maintaining cosmic magnetic fields. A few analytical models exist to describe their behavior, but they are based on simplifying assumptions. ...

AMER PHYSICAL SOC2023

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