Publications associées à Cycle of erosion

Mechanistic 2D flow-erosion modelling of vegetated river banks

Giovanni De Cesare, Paolo Perona, Massimiliano Schwarz

We present a simple, vertically-explicit 2D model of river bank erosion that also takes the effect of sediment stabilization by plant roots into account. The model is solved in quasi-analytical form for an exemplary non-stationary hydrograph temporal signa ...

2023

Plasma sputtering of biased electrodes in an oblique magnetic field

Stefano Alberti, Ivo Furno, Alessandro Geraldini

The surface erosion of biased electrodes immersed in a radio frequency (RF) plasma was investigated in oblique magnetic fields ranging from 0.1 T to 3.5 T. The plasma potential and density in the vicinity of the biased electrode have been measured using an ...

IOP Publishing Ltd2023

p Spatio-temporal deposition profile of an experimentally produced turbidity current with a continuous suspension supply

Giovanni De Cesare, Shun Nomura

A turbidity current is a turbulent, particle-laden gravity current that is driven by density differences resulting from the presence of suspended sediment particles. The current travels downslope, bearing a large amount of sediment over a great distance, a ...

2022

Multiscale simulation of erosive wear in a prototype-scale Pelton runner

François Avellan, Ebrahim Jahanbakhsh, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

The technical capacity to predict the erosion process is instrumental for the optimization of the runner designs and operation strategies of hydroelectric plants. A multiscale model of erosion recently formulated by the authors and validated on a laborator ...

Pergamon-Elsevier Science Ltd2020

Quasi-stationary flow structure in turbidity currents

Giovanni De Cesare, Shun Nomura

A turbidity current is a particle-laden current driven by density differences due to suspended sediment particles. Turbidity currents can transport large amounts of sediment down slopes over great distances, and play a significant role in fluvial, lake and ...

IRTCES2020

Erosion processes of a novel configuration of sediment replenishment during an artificial flood

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Severin Stähly, Christopher Robinson

Floodplains downstream of dams with constant residual flow discharge often lack sediment supply and periodic inundation due to the absence of flood events. At the Sarine floodplain in Fribourg, western Switzerland, an artificial flood was released from Ros ...

2019

Multiscale Modeling and Simulation of Erosive Wear in Pelton Turbines

Sebastián Camilo Leguizamón Sarmiento

Hydropower has been identified as a key technology to mitigate climate change due to its very low lifecycle greenhouse gas emission intensity and its capacity to integrate intermittent renewable energy sources such as wind and solar into the electrical gri ...

EPFL2019

FVPM numerical simulation of the effect of particle shape and elasticity on impact erosion

François Avellan, Ebrahim Jahanbakhsh, Audrey Paulette Solange Maertens, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

The erosion of hydraulic machines by solid particle impacts is a widespread problem that leads to outage for expensive repairs, efficiency reduction, and cavitation enhancement. Numerical simulations can be used to study the phenomenon, provided they featu ...

ELSEVIER SCIENCE SA2019

Multiscale Simulation of the Hydroabrasive Erosion of a Pelton Bucket: Bridging Scales to Improve the Accuracy

François Avellan, Ebrahim Jahanbakhsh, Audrey Paulette Solange Maertens, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

Erosive wear of hydraulic machines is a common issue, which results in efficiency degradation, the enhancement of cavitation, and the need for expensive maintenance. Although numerical simulations of the erosion process could be very useful, both for under ...

2019

Erosion, screening, and migration of tungsten in the JET divertor

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Henri Weisen, Federico Nespoli, Alessandro Pau, David Pfefferlé, Cristian Sommariva, Jonathan Marc Philippe Faustin, Richard Pitts, Hamish William Patten, Yann Camenen, Samuel Lanthaler, Jan Horacek, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Yao Zhou, Davide Galassi, Antonio José Pereira de Figueiredo, Liang Yao, Dalziel Joseph Wilson, Bernhard Sieglin, Otto Asunta

The erosion of tungsten (W), induced by the bombardment of plasma and impurity particles, determines the lifetime of plasma-facing components as well as impacting on plasma performance by the influx of W into the confined region. The screening of W by the ...

IOP Publishing Ltd2019

Simulation of the hydroabrasive erosion of a bucket: A multiscale model with projective integration to circumvent the spatio-temporal scale separation

François Avellan, Ebrahim Jahanbakhsh, Audrey Paulette Solange Maertens, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

The hydroabrasive erosion of hydraulic machine components, especially Pelton buckets and needles, is a widespread problem that entails significant costs. The multiscale nature of the process renders its simulation very computationally demanding unless spec ...

IOP PUBLISHING LTD2019

Statistical and physical characterization of rainfall-driven overland flow morphologies

Mohsen Cheraghi

Environmental transport processes are highly coupled with the shape of landscapes. Modern catchment analysis with high-resolution data and huge computational powers demand more detailed within-cell metrics for surface evolution modeling. This dissertation ...

EPFL2019

Experiments with sediment replenishment in a residual flow reach: Comparison of field datawith laboratory experiments

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Severin Stähly, Christopher Robinson

Hydropower is an important pillar of the electricity production in Switzerland and its extension is planned in the next decades. Therefore, a more sustainable management of hydropower plants is needed. Sediment replenishment combined with artificially-trig ...

2018

Investigation into the formation of the scrape-off layer density shoulder in JET ITER-like wall L-mode and H-mode plasmas

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Martinus Gijs, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Bruno Emanuel Ferreira De Sousa Correia, Alessandro Pau, Pierre-Thomas Paul Brun, Cristian Sommariva, Henri Weisen, Richard Pitts, Sun Hee Kim, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Mikhail Maslov, Nicola Vianello, Miguel Fernández Ruiz, Federico Nespoli, Antonio José Pereira de Figueiredo, Liang Yao, Yao Zhou, David Pfefferlé, Dalziel Joseph Wilson, Robin Humphry-Baker, Davide Galassi, José Pedro Rebelo Ferreira Marques, Ana Francisca Leal Silva Soares, Jonathan Marc Philippe Faustin, Daniel Scott Alessi, Arnout Lodewijk M Beckers, Julio Rodriguez, Hamish William Patten, Jonnathan Cesar Hidalgo Acosta, , , , , , , , ,

Entrainment, transport and deposition of sediment by saline gravity currents

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Jessica Zordan

Few studies have addressed simultaneously the feedback between the hydrodynamics of a gravity cur- rent and the geomorphological changes of a mobile bed. Hydrodynamic quantities such as turbulent and mean velocities, bed shear stress and turbulent stresses ...

2018

Experiments on the effect of inflow and outflow sequences on suspended sediment exchange rates

Anton Schleiss, Giovanni De Cesare, Michael Müller

In laboratory experiments, the influence of inflow and outflow sequences on the behavior of fine sediment was investigated. The experimental set-up consisted of two interconnected rectangular basins, between which water was moved back and forth. Suspended ...

Irtces2017

Scale-free channeling patterns near the onset of erosion of sheared granular beds

Matthieu Wyart

Erosion shapes our landscape and occurs when a sufficient shear stress is exerted by a fluid on a sedimented layer. What controls erosion at a microscopic level remains debated, especially near the threshold forcing where it stops. Here we study, experimen ...

Natl Acad Sciences2016

Managing reservoir sedimentation by venting turbidity currents: A review

Anton Schleiss, Giovanni De Cesare, Sabine Chamoun

Reservoir sedimentation is an issue that dam operators are increasingly facing as dams are aging. Not only does it reduce a reservoir's capacity but it also affects its outlet structures such as bottom outlets and powerhouse intakes. Sedimentation may also ...

Irtces2016

Physical modelling of artificial river replenishment techniques to restore morphological conditions downstream of dams

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Elena Battisacco

First applied in the 1980’s, the artificial replenishment of sediments is one technique proposed to solve the problem of sediment deficit downstream dams. The present experimental research aims at improving the technique of river replenishment and at provi ...

2015

Experimental characterization of vegetation uprooting by flow

Paolo Perona, Benoît Crouzy, Katharina Maria Edmaier

We investigate vegetation uprooting by flow for Avena sativa seedlings with stem-to-sediment size ratio close to unity and vanishing obstacle-induced scouring. By inducing parallel riverbed erosion within an experimental flume, we measure the time-to-uproo ...

2015