Publications associées à Head loss coefficient through sharp-edged orifices

CFD simulations of hydraulic short-circuits in junctions, application to the Grand’Maison power plant

In the framework of the XFLEX HYDRO H2020 European Project, the pumped-storage power plant of Grand'Maison (France), owned by Electricité De France, focuses on the implementation of the hydraulic short-circuit (HSC) operating mode. This mode increases the ...

2022

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

Numerical simulations of Pelton turbine flow to predict large head variation influence

François Avellan, Steve Crettenand, Cécile Münch-Alligné, Siamak Alimirzazadeh

In the framework of the new feed-in-tariff system in Switzerland for Small Hydropower Plants (SHP), the aim of the SmallFLEX project, led by HES-SO Valais and performed in collaboration with EPFL, WSL, EAWAG, PVE, and FMV, is to show how SHP can provide wi ...

IOP PUBLISHING LTD2021

The complex winds of the Alps: an unseen asset for the energy transition

Jérôme François Sylvain Dujardin

Wind energy has played a major role in the development of our society since 5000 BC when the first sail boats traveled the Nile River. Wind technology continued to advance with the invention of wind-powered pumps and mills in China and the Middle East as e ...

EPFL2021

Heightening of Very High Gravity Dams: The Case Study of the Grande Dixence

Giovanni De Cesare, Pedro Filipe De Almeida Manso, Basile Clerc

Heightening very high gravity dams is one of the solutions considered as part of the energy transition and to mitigate the effects of climate change. The paper presents a stepwise approach to assess the potential for dam heightening and its impact on the h ...

Springer, Cham2020

Hybrid modeling and design review of throttled surge tanks

Giovanni De Cesare, Bernard Valluy, Samuel Luke Vorlet, Nicolas Jean François Pascal Ghislain Adam, Mona Seyfeddine

The 2050 Swiss Energy Strategy aims to increase the annual production of hydroelectricity by 4% while 90% of the technically feasible potential is already used. The flexibility of high-head storage power plants (HPP), the main pillar of Swiss peak electric ...

2020

Siting and Sizing of Energy Storage Systems: Towards a Unified Approach for Transmission and Distribution System Operators for Reserve Provision and Grid Support

Mario Paolone, Fabrizio Sossan, Paola Pongiglione

This paper presents a method to determine the optimal location, energy capacity, and power rating of distributed battery energy storage systems at multiple voltage levels to accomplish grid control and reserve provision. We model operational scenarios at a ...

Elsevier2020

Numerical Simulations of an Innovative Water Stirring Device for Fine Sediment Release: The Case Study of the Future Trift Reservoir

Pedro Filipe De Almeida Manso, Azin Amini, Anass Chraibi

Reservoir sedimentation and consequently lack of storage volume and perturbation of the operation of intakes and bottom outlet is a key challenge affecting both hydropower production as well as dam safety and flood management. In the framework of a peer-re ...

Springer2020

Stilling Basin Performance Downstream of Stepped Spillways

Ivan Stojnic

Advances in dam construction techniques have significantly increased the number of implemented stepped spillways worldwide. A key hydraulic feature of a stepped chute, compared to a smooth chute, is the enhanced energy dissipation resulting in a reduced re ...

EPFL2020

Physical and numerical model studies of the Martigny bend as part of 3rd correction of the Rhone River

Giovanni De Cesare, Stéphanie Joëlle André, Azin Amini, Jean-Noël Saugy

The 3rd correction of the Rhone River (R3) is the largest flood protection project in Switzerland so far. Covering a length of 162 km, it aims to protect some 100,000 people and prevent flood damages, which could raise up to 10 billion CHF for major events ...

CRC press2020

Optimal path to a high share of distributed PV in low-voltage distribution grids

Lionel Benjamin Bloch

To limit global warming, the energy transition from fossil fuels to renewables is one of the main challenges of this century. This transition will help decrease our CO2 emissions, create jobs, contribute to a broader revenues distribution, improve energy s ...

EPFL2020

Bottom pressure characteristics in a stilling basin downstream of a stepped spillway for two different chute slopes

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos, Michael Pfister, Ivan Stojnic

In the last decades numerous stepped spillways were built, mostly on the downstream face of roller compacted concrete (RCC) dams. Stilling basins are often used as an energy dissipater. Although the hydraulics of stepped chutes was extensively investigated ...

The University of Queensland2020

Influence of geometrical parameters of chamfered or rounded orifices on head losses

Giovanni De Cesare, Anton Schleiss, Nicolas Jean François Pascal Ghislain Adam

Orifices are largely used in pipeline systems. The most common application is to measure the discharge of the water flowing through. However, orifices may be used to adapt hydroelectric power plants submitted to moderate increase of installed generation ca ...

Taylor & Francis Ltd2019

COREDIV numerical simulation of high neutron rate JET-ILW DD pulses in view of extension to JET-ILW DT experiments

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Martinus Gijs, Partha Dutta, Marco Wischmeier, Jan Horacek, Vlad Trifa, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Ricardo Lima, Duccio Testa, Emiliano Fable, Sun Hee Kim, Mikhail Maslov, Javier García Hernández, Soo-Jin Moon, Federico Alberto Alfredo Felici, José Pedro Rebelo Ferreira Marques, Julio Rodriguez, Pedro Camilo de Oliveira e Silva, Daniel Scott Alessi, Daniele Brunetti, Jonnathan Cesar Hidalgo Acosta, Ana Francisca Leal Silva Soares, Dalziel Joseph Wilson, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Alberto Hernando de Castro, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Bruno Emanuel Ferreira De Sousa Correia, Li Shuai, , , , , , , , , , , , , , ,

Predicting the dynamic behavior of Francis turbine generating units

Joao Gomes Pereira Junior

To reduce CO2 emissions and tackle global warming, an increasing amount of electrical power consumed around the world must be obtained from renewable sources. Among these sources, hydropower has not only the advantage of leaving a very small carbon footpri ...

EPFL2019

Design of a Throttled Surge Tank for Refurbishment by Increase of Installed Capacity at a High-Head Power Plant

Giovanni De Cesare, Bernard Valluy, Anton Schleiss, Nicolas Jean François Pascal Ghislain Adam

The Swiss confederation aims to phase out nuclear power production with its Energy Strategy 2050 program by increasing the renewable energy contribution to its overall energy generation. Hydroelectricity, which is the most important form of renewable energ ...

American Society of Civil Engineers2018

Spatially Sampled Pressure Profile Measurements in Externally Pressurized Gas Journal Bearings

Jürg Alexander Schiffmann, Eliott Philippe Guenat, Karim Magdi Zakaria Abdelrahman Shalash

Externally pressurized gas journal bearings (EPGJB) are widely adopted to support high speed rotors. This paper presents novel experimental benchmark test data which enables EPGJB model validation. Axial and circumferential pressure profile measurements ar ...

2018

Pumps running as turbines for energy recovery in water supply systems

João Nuno Gomes Borga Delgado

Pressurised water supply systems are infrastructures that offer a potential for energy recovery in locations where these systems operate with an excessive pressure. The integration of micro hydropower plants for energy recovery is a challenge, as these sys ...

EPFL2018

Dynamics and Optimal Control of Self-Sustained Instabilities in Laminar and Turbulent Swirling Flows: Application to the Part Load Vortex Rope in Francis Turbines

Simon Pasche

In 2050, the European commission plans to achieve actual energetic transition, which contributes in meeting the climate change challenges by moving away from the fossil fuels and by developing a competitive low-carbon economy. As a consequence, a foreseeab ...

EPFL2018

Characterization of hydraulic behavior of orifices in conduits

Nicolas Jean François Pascal Ghislain Adam

High-head power plants are the main pillar of Swiss peak electricity production. With the 2050 Energy Strategy approved by Swiss voters, the annual production of hydroelectricity should increase by 4%, while 90% of the technically feasible potential is alr ...

EPFL2017