Publications associées à Parametric study on the influence of jet-like inflows and outflows on fine sediment settling

Adaptive Finite Elements with Large Aspect Ratio. Application to Aluminium Electrolysis

The goal of this work is to use anisotropic adaptive finite elements for the numerical simulation of aluminium electrolysis. The anisotropic adaptive criteria are based on a posteriori error estimates derived for simplified problems. First, we consider an ...

EPFL2024

A cut-cell method for the numerical simulation of 3D multiphase flows with strong interfacial effects

Alexandre Caboussat, Alexandre Masserey, Marco Picasso, Julien Hess

We present a numerical model for the approximation of multiphase flows with free surfaces and strong interfacial effects. The model relies on the multiphase incompressible Navier-Stokes equations, and includes surface tension effects on the interfaces betw ...

Academic Press Inc Elsevier Science2024

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

Mean-field transport equations and energy theorem for plasma edge turbulent transport

Reinart Andreas J. Coosemans

This paper establishes a mean-field equation set and an energy theorem to provide a theoretical basis in view of the development of self-consistent, physics-based turbulent transport models for mean-field transport codes. A rigorous averaging procedure ide ...

Cambridge University Press2024

Full-F turbulent simulation in a linear plasma device using a gyro-moment approach

Paolo Ricci, Baptiste Jimmy Frei

Simulations of plasma turbulence in a linear plasma device configuration are presented. These simulations are based on a simplified version of the gyrokinetic (GK) model proposed by Frei et al. [J. Plasma Phys. 86, 905860205 (2020)], where the full-F distr ...

Aip Publishing2024

Nonlinear simulation of plasma turbulence using a gyrokinetic moment-based approach

Antoine Cyril David Hoffmann

Plasma turbulence plays a fundamental role in determining the performances of magnetic confinement fusion devices, such as tokamaks. Advances in computer science, combined with the development of efficient physical models, have significantly improved our u ...

EPFL2024

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

Mehrdad Kiani Oshtorjani

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

Global fluid simulation of plasma turbulence in stellarators with the GBS code

Joaquim Loizu Cisquella, Paolo Ricci, António João Caeiro Heitor Coelho

The implementation of three-dimensional magnetic fields, such as the ones of stellarators, in the GBS code (Ricci et al 2012 Plasma Phys. Control. Fusion54 124047; Giacomin et al 2022 J. Comput. Phys.464 111294) is presented, and simulation results are dis ...

IOP Publishing Ltd2024

The effect of pressure-anisotropy-driven kinetic instabilities on magnetic field amplification in galaxy clusters

Yoan Rappaz, Jennifer Waltraud Schober

Context. The intracluster medium (ICM) is the low-density diffuse gas that fills the space between galaxies within galaxy clusters. It is primarily composed of magnetized plasma, which reaches virial temperatures of up to 10(8) K, probably due to mergers o ...

Edp Sciences S A2024

Toward Wearable Biosensing by Spectroscopy-free Raman Shift Detection and Soft Optofluidics

Ata Jedari Golparvar

This thesis introduces spectroscopy-free Raman biosensing, which may find increasing use in the next generation of wearable devices for preventive healthcare. While wearables have made substantial advancements in detecting physical biomarkers, they have ye ...

EPFL2024

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

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

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

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

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

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

Simulation of fine sediment deposition on floodplains

Giovanni De Cesare, Carmelo Juez Jiménez

Rivers extend beyond the channels that are typically associated with this word. Of particular interest are flood plains, where important hydro- and morphodynamic processes occur as a result of recurrent flooding. Ecologically, they also support the establi ...

2023

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

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

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