Publications by Sébastien Alligné

Turbine mode start-up simulation of a FSFC variable speed pump-turbine prototype - Part I: 1D simulation

François Avellan, Drazen Dujic, Sébastien Alligné, Antoine Béguin

Variable speed hydroelectric units equipped with full size frequency converter (FSFC) offer high operational flexibility enabling fast operating point transitions which increase grid regulation capacities. The XFLEX HYDRO H2020 European research project ai ...

IOP PUBLISHING LTD2021

Procedure for predicting part load resonance in Francis turbine hydropower units based on swirl number and local cavitation coefficient similitude

François Avellan, Christophe Nicolet, Arthur Tristan Favrel, Christian Landry, Loïc Andolfatto, Sébastien Alligné

Francis turbines operating at part load conditions develop a cavitation precessing vortex known as a vortex rope in the draft tube cone below the runner outlet. At part load conditions, this vortex precession acts as an excitation source inducing pressure ...

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD2019

Reduced scale model testing for prediction of eigenfrequencies and hydro-acoustic resonances in hydropower plants operating in off-design conditions

François Avellan, Christophe Nicolet, Arthur Tristan Favrel, Joao Gomes Pereira Junior, Christian Landry, Sébastien Alligné

The massive penetration of the electrical network by renewable energy sources, such as wind and solar, pushes the operators to extend hydropower plant units operating range to meet the transmission system operator requirements. However, in off-design opera ...

2019

Prediction of hydro-acoustic resonances in hydropower plants by a new approach based on the concept of swirl number

François Avellan, Christophe Nicolet, Arthur Tristan Favrel, Christian Landry, Sébastien Alligné, Loïc Andolfatto, Joao Gomes Pereira Junior

Hydropower plant units operating in off-design conditions are subject to cavitation flow instabilities, potentially inducing hydro-acoustic resonances under certain conditions. They can be predicted by using one-dimensional numerical models of hydropower p ...

Taylor & Francis Ltd2019

Prediction of Francis Turbine Prototype Part Load Pressure and Output Power Fluctuations with Hydroelectric Model

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 ...

2017

Experimental investigation of the mass flow gain factor in a draft tube with cavitation vortex rope

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

At off-design operating operations, cavitating flow is often observed in hydraulic machines. The presence of a cavitation vortex rope may induce draft tube surge and electrical power swings at part load and full load operations. The stability analysis of t ...

2017

RANS computations for identification of 1-D cavitation model parameters: application to full load cavitation vortex rope

François Avellan, Christophe Nicolet, Andres Müller, Sébastien Alligné

Due to the massive penetration of alternative renewable energies, hydropower is a key energy conversion technology for stabilizing the electrical power network by using hydraulic machines at off design operating conditions. At full load, the axisymmetric c ...

2017

RANS computations for identification of 1-D cavitation model parameters: application to full load cavitation vortex rope

François Avellan, Christophe Nicolet, Andres Müller, Sébastien Alligné

Due to the massive penetration of alternative renewable energies, hydropower is a key energy conversion technology for stabilizing the electrical power network by using hydraulic machines at off design operating conditions. At full load, the axisymmetric c ...

International Association For Hydraulic Research2016

Measurement of the Self-Oscillating Vortex Rope Dynamics for Hydroacoustic Stability Analysis

François Avellan, Sébastien Alligné, Keita Yamamoto

Flow instabilities in hydraulic machines often feature oscillating cavitation volumes, which locally introduce compliance and mass flow gain effects. These unsteady characteristics play a crucial role in one-dimensional stability models and can be determin ...

American Society of Mechanical Engineers2016

Hydroelectric System Response to Part Load Vortex Rope Excitation

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

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