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

Twenty years of irrigation acclimation is driven by denser canopies and not by plasticity in twig- and needle-level hydraulics in a Pinus sylvestris forest

Charlotte Grossiord, Eugénie Isabelle Mas, Christoph Bachofen, Alex Tunas Corzon, Hervé Cochard, Alice Jacqueline Frédérique Gauthey

Climate change is predicted to increase atmospheric vapor pressure deficit, exacerbating soil drought, and thus enhancing tree evaporative demand and mortality. Yet, few studies have addressed the longer-term drought acclimation strategy of trees, particul ...

Oxford Univ Press2024

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

Structural impact of the start-up sequence on Pelton turbines lifetime: Analytical prediction and polynomial optimization

Mario Paolone, Elena Vagnoni, Aldo Leonardo Alerci

Hydropower plants play a crucial role in the power system facing ambitious renewable energy targets. Due to their inherent controllability, they are well suited to provide flexibility to the grid. However, an increased flexibility provision leads to a prol ...

Pergamon-Elsevier Science Ltd2023

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

Different erosion and entrainment mechanisms in snow avalanches

Betty Sovilla, Johan Alexandre Philippe Gaume, 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

Mercury isotope evidence for Arctic summertime re-emission of mercury from the cryosphere

Jenny Thomas, Jakob Boyd Pernov

During Arctic springtime, halogen radicals oxidize atmospheric elemental mercury (Hg0), which deposits to the cryosphere. This is followed by a summertime atmospheric Hg0 peak that is thought to resultmostly fromterrestrial Hg inputs to the ArcticOcean, fo ...

Nature Research2022

Experimental and Numerical Study on Scour-Protection Methods in a Stilling Basin: Case Study of Chancy-Pougny Dam

Giovanni De Cesare, Erik Bollaert, Anton Schleiss, Sabine Chamoun, Davide Wüthrich

Chancy-Pougny is a run-of-river dam on the Swiss–French border constructed in the early 1920s. Since its commissioning, the operation of the four spillway gates has been responsible for a progressive erosion of the stilling basin. The future scour potentia ...

2021

Optimal CAM Computation of Kaplan Turbines Accounting for Wear and Tear Originated by Frequency Control

Sidi-Rachid Cherkaoui, Mario Paolone, Elena Vagnoni, Francesco Gerini

Nowadays, the importance of providing frequency stability to power systems with hydropower units is significantly increasing due to the growing proportion of volatile renewable energy sources. However, the provision of such services, as frequency containme ...

IEEE2021

Third correction of the Rhône River in Switzerland: physical and numerical modelling of the “Martigny bend” priority measure

Giovanni De Cesare, Stéphanie Joëlle André, Azin Amini, Pierre Bourqui, Jean-Noël Saugy, Irene Almeida Samora

The Rhône River, second largest in Switzerland, has already been corrected twice (1863-1893; 1930-1960) to ensure safety and economic development in the Rhône valley. However, in October 2000, the highest flood of the century occurred showing the limitatio ...

International Research Society INTERPRAEVENT2021

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

Assessing Subaquatic Mass Movement Hazards: an Integrated Observational and Hydrodynamic Modelling Approach

Alfred Johny Wüest, Damien Bouffard, Nathalie Dubois, Carl Love Mikael Råman Vinnå

High-resolution lake and reservoir bathymetric surveys can pinpoint locations that may experience underwater landslides (subaquatic sedimentary mass movements). These can pose a risk to underwater and shoreline infrastructure. This paper outlines an approa ...

2020

A Novel Method for River Bank Detection from Landsat Satellite Data: A Case Study in the Vietnamese Mekong Delta

Giovanni De Cesare, Sameh Ahmad Kantoush

River bank (RB) erosion is a global issue aecting livelihoods and properties of millions of people. However, it has not received enough attention in the Vietnamese Mekong Delta (VMD), i.e., the world’s third largest delta, compared to salinity intrusion an ...

2020

Study of Aerodynamic Grain Entrainment in Aeolian Transport

Aeolian transport controls landform formations on Earth and other planets and crucially affects the atmospheric system. With elaborate wind tunnel measurements, we find that the aerodynamic entrainment rate follows a yet unreported exponential increase in ...

2020

Evaluation of a Dynamic Transfer Matrix for a Hydraulic Turbine

François Avellan, Andres Müller, Keita Yamamoto

It is well known that hydraulic machines experience various types of flow instabilities causing a negative influence on the system under off-design operations. The transfer matrix method correlating the flow properties in upstream and downstream of hydraul ...

2020

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

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

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

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

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

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 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

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

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

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

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