Recherche

Afficher tous les résultats pour

Accueil

Personne

François Avellan

Cette personne a quitté l’EPFL

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (218)

Page 5 sur 11

Advanced Instrumentation for Measuring Fluid-Structure Coupling Phenomena in the Guide Vanes Cascade of a Pump-Turbine Scale Model

François Avellan, Mohamed Farhat, Vlad Hasmatuchi, Steven Roth

In the present study, the fluid-structure coupling is investigated in the guide vanes of a pump-turbine scale model placed in one of the test rigs of the Laboratory for Hydraulic Machines (EPFL) in Lausanne. The paper focuses on the advanced instrumentatio ...

American Soc Mechanical Engineers, Three Park Avenue, New York, Ny 10016-5990 Usa2010

New insight in Francis turbine cavitation vortex rope: role of the runner outlet flow swirl number

François Avellan, Christophe Nicolet, Arthur Tristan Favrel, Andres Müller, Christian Landry, Joao Gomes Pereira Junior

At part load operation, Francis turbines experience the development of a cavitation vortex rope in the draft tube, whose precession acts as a pressure excitation source. In case of resonance, the resulting pressure pulsations lead to unacceptable torque an ...

Taylor & Francis Ltd2018

A mixed standard/custom design strategy to minimize cost and maximize efficiency for picohydro power potential harvesting

François Avellan, Elena Vagnoni, Loïc Andolfatto, Cécile Münch-Alligné

Harvesting the numerous small scale hydroelectric potential is a way to increase the sustainable hydraulic energy production in developed countries. The condition to meet economical profitability with pico power stations - below 25 kW - is to minimize the ...

2015

Experimental Investigation of Pressure Fluctuations in a High-Energy Centrifugal Pump Stage at Off-Design Conditions

François Avellan, Mohamed Farhat, Philippe Dupont

In centrifugal pumps, the interaction between the rotating impeller blades and the stationary diffuser vanes generates specific pressure fluctuation patterns. At off design operation, high incidence and large local pressure gradients can lead to flow separ ...

Institution of Mechanical Engineers2014

Turbulence modeling for Francis turbine water passages simulation

François Avellan, Pierre Maruzewski, Henri-Pascal Mombelli

The applications of Computational Fluid Dynamics, CFD, to hydraulic machines life require the ability to handle turbulent flows and to take into account the effects of turbulence on the mean flow. Nowadays, Direct Numerical Simulation, DNS, is still not a ...

International Association For Hydraulic Research2010

Toward design optimization of a Pelton turbine runner

François Avellan, Loïc Andolfatto, Christian Vessaz

The objective of the present paper is to propose a strategy to optimize the performance of a Pelton runner based on a parametric model of the bucket geometry, massive particle based numerical simulations and advanced optimization strategies to reduce the d ...

Springer Verlag2017

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

François Avellan, Cécile Münch-Alligné

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 Analysis or Free Surface Flows in a Rotating Bucket

François Avellan, Sonia Kvicinsky

The aim of this study was to provide a complete experimental and numerical analysis of the flow in a rotating Pelton bucket. For the experimental analysis, several functioning points have been used in order to study differences which may occur in various s ...

International Association For Hydraulic Research2002

Rotating air-water ring in the vaneless gap of a pump-turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto

The rotating air-water ring, featuring a bubbly flow, in the vaneless gap of a reduced scale physical model of a pump-turbine operating in dewatered condition is investigated. High speed visualizations are performed together with pressure fluctuation measu ...

2018

Dynamics of the precessing vortex rope and its interaction with the system at Francis turbines part load operating conditions

François Avellan, Arthur Tristan Favrel, Christian Landry, Andres Müller, Keita Yamamoto, Joao Gomes Pereira Junior

At part load conditions, Francis turbines experience the formation of a cavitation vortex rope at the runner outlet whose precession acts as a pressure excitation source for the hydraulic circuit. This can lead to hydro-acoustic resonances characterized by ...

2017

Hydro-acoustic resonance behavior in presence of a precessing vortex rope: observation of a lock-in phenomenon at part load Francis turbine operation

François Avellan, Arthur Tristan Favrel, Andres Müller, Christian Landry, Keita Yamamoto

Francis turbines operating at part load condition experience the development of a cavitating helical vortex rope in the draft tube cone at the runner outlet. The precession movement of this vortex rope induces local convective pressure fluctuations and a s ...

IOP science2014

Hydroelectric System Response to Part Load Vortex Rope Excitation

François Avellan, Christophe Nicolet, Christian Landry, Sébastien Alligné, Joao Gomes Pereira Junior, Antoine Béguin

The prediction of pressure and output power fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 re ...

International Association For Hydraulic Research2016

Numerical capture of wing tip vortex improved by mesh adaptation

François Avellan

This paper presents a mesh adaptation procedure linked to a finite volume solver, the goal of which is to increase the precision of the numerical simulation of a wing tip vortex flow. The adaptation scheme is applied to hexahedron meshes and hybrid meshes ...

2011

Predictive control of spiral vortex breakdown

François Avellan, François Gallaire, Simon Pasche

The predictive control of the self-sustained single spiral vortex breakdown mode is addressed in the three-dimensional flow geometry of Ruith et al. (2003) for a constant swirl number S = 1.095. Based on adjoint optimization algorithms, two different contr ...

Cambridge University Press2018

Overload Surge Event in a Pumped-Storage Power Plant

François Avellan, Christophe Nicolet

At full load, pump-turbines operating in generating mode may experience a cylindrical cavitation vortex rope caused by the swirling flow in the draft tube cone. Under certain conditions, this vortex rope initiates both pressure and power oscillations. The ...

International Association For Hydraulic Research2006

LDV survey of cavitation and resonance effect on the precessing vortex rope dynamics in the draft tube of Francis turbines

François Avellan, Arthur Tristan Favrel, Christian Landry, Keita Yamamoto

The large-scale penetration of the electrical grid by intermittent renewable energy sources requires a continuous operating range extension of hydropower plants. This causes the formation of unfavourable flow patterns in the draft tube of turbines and pump ...

Springer Verlag2016

GPU-accelerated Pelton turbine simulation using finite volume particle method coupled with linear eddy viscosity models

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

The numerical investigation of the unsteady flow patterns around a Pelton bucket can be helpful to improve the overall turbine efficiency by optimizing the bucket design based on identified loss mechanisms. Since the flow is highly turbulent, modeling the ...

IOP Publishing2019

Analysis of the dynamic response of pump-turbine runners- Part I: Experiment

François Avellan, Mohamed Farhat, Xiaopeng Huang

When in operation, pump-turbine runners have to withstand large pressure pulsations generated by the rotor-stator interaction. The analysis of the dynamic behavior of these structures is necessary to avoid damage. For this analysis a realistic model of the ...

International Association For Hydraulic Research2012

A multiscale model for the simulation of sediment impact erosion of metallic targets using the finite volume particle method

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

2017

Centrifugal Pump Performance Drop due to leading Edge Cavitation : Numerical Predictions compared with Model Tests

François Avellan, Philippe Dupont

1998