Publications associées à Attrition (érosion)

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

Impact of substrate clogging on vertical connectivity

Giovanni De Cesare, Romain Maxime Dubuis, Robin Schroff

Connectivity between the hyporheic zone and the flow is essential for the development of benthos and the reproductive success of spawning fish. The infiltration of fine sediment leads to clogging of the riverbed, reducing porosity and vertical water exchan ...

2023

Different erosion and entrainment mechanisms in snow avalanches

Johan Alexandre Philippe Gaume, Betty Sovilla, Xingyue Li

Erosion significantly affects the dynamics of gravity-driven mass flows. In snow avalanches, the snow cover can be substantially eroded but only partially entrained, however, there are very limited investigations to substantiate this difference. Here, we s ...

PERGAMON-ELSEVIER SCIENCE LTD2022

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

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

Preferential Deposition of Snow and Dust Over Hills: Governing Processes and Relevant Scales

Michael Lehning, Marc Parlange, Francesco Comola, Marco Giovanni Giometto

Preferential deposition of snow and dust over complex terrain is responsible for a wide range of environmental processes and accounts for a significant source of uncertainty in the surface mass balances of cold and arid regions. Despite the growing body of ...

2019

Stochastic bedload transport in mountain streams

Christophe Ancey

Describing bedload transport as a stochastic process is an idea that emerged in the 1930s with the pioneering work of Einstein. For a long time, the stochastic approach attracted marginal attention, but the situation has radically changed over the last dec ...

EDP Sciences2018

Measuring Bedload Sediment Transport with an Acoustic Doppler Velocity Profiler

Koen Blanckaert, Joris Heyman

Acoustic Doppler velocity profilers (ADVP) measure the velocity simultaneously in a linear array of bins. They have been successfully used in the past to measure three-dimensional turbulent flow and the dynamics of suspended sediment. The capability of ADV ...

Asce-Amer Soc Civil Engineers2017

Erosion mechanisms during abrasive waterjet machining: Model microstructures and single particle experiments

Stefano Mischler, Johann Michler

The erosion mechanisms during abrasive waterjet (AWJ) machining have been examined for a variety of materials. However, no systematic study has considered the effect of the microstructure property relationship on the erosion mechanisms in metals. In this w ...

Elsevier Science Sa2017

Sediment Pulses in a Gravel-Bed Flume with Alternate Bars

Blaise Etienne Marceau Dhont

The proper understanding of gravel-bed river dynamics is a crucial issue for the effective protection against related natural hazards, design of hydraulic structures, and preservation of their high ecological value in mountain regions. However, despite mor ...

EPFL2017

Hydrodynamics of mountain-river confluences and its relationship to sediment transport

Mário Jorge Rodrigues Pereira Da Franca, Sebastián Guillén Ludeña

Mountain confluences are characterized by narrow and steep tributaries that provide important sediment load to the confluence, whereas themain channel supplies the dominant flow discharge. This results in a marked bed discordance between the tributary and ...

American Geophysical Union2017

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

A parametrical study on secondary flow in sharp open-channel bends: experiments and theoretical modelling

Anton Schleiss, Koen Blanckaert, Joris Heyman

The dependence of curvature-induced secondary flow on the curvature ratio H/R (H is the average flow depth and R is the centreline radius of curvature), the Froude number Fr, and the dimensionless roughness coefficient Cf was systematically investigated in ...

Elsevier Science Bv2016

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

Thermal energy in dry snow avalanches

Michael Lehning, Walter Steinkogler

Avalanches can exhibit many different flow regimes from powder clouds to slush flows. Flow regimes are largely controlled by the properties of the snow released and entrained along the path. Recent investigations showed the temperature of the moving snow t ...

Copernicus Gesellschaft Mbh2015

Influence of snow cover properties on avalanche dynamics

Walter Steinkogler

Snow avalanches are a direct thread to many mountain communities around the world and already small avalanches can endanger traffic routes and result in loss of life or property. Their destructive power depends, among other things, on the overall mass and ...

EPFL2015

Bed load fluctuations in a steep channel

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Tamara Ghilardi

Bedload transport rate fluctuations have been observed over time in steep rivers and flumes with wide grain size distributions even under constant sediment feeding and water discharge. The observed bedload transport rate pulses are periodic and a consequen ...

American Geophysical Union2014

Sediment transport in steep channels with large roughness elements

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Tamara Ghilardi

Most sediment transport equations overestimate the bedload transport rate by several times when applied to mountain rivers. This is due to the fact that the presence of large relatively immobile boulders, which disrupt the flow, is generally not taken into ...

CRC Press/Balkema2014