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Arthur Tristan Favrel

Cette personne n’est plus à l’EPFL

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Publications associées (38)

Mechanical impact of dynamic phenomena in Francis turbines at off design conditions

François Avellan, Arthur Tristan Favrel

At partial load and overload conditions, Francis turbines are subjected to hydraulic instabilities that can potentially result in high dynamic solicitations of the turbine components and significantly reduce their lifetime. This study presents both experim ...

2017

Unsteady hydraulic simulation of the cavitating part load vortex rope in Francis turbines

François Avellan, Arthur Tristan Favrel

For Francis turbines at part load operation a helical vortex rope is formed due to the swirling nature of the flow exiting the runner. This vortex creates pressure fluctuations which can lead to power swings, and the unsteady loading can lead to fatigue da ...

2017

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

François Avellan, Christian Landry, Arthur Tristan Favrel, 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

Numerical and experimental evidence of the inter-blade cavitation vortex development at deep part load operation of a Francis turbine

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

Francis turbines are subject to various types of the cavitation flow depending on the operating condition s. In order to compensate for the stochastic nature of renewable energy sources, it is more and more required to extend the operating range of the gen ...

International Association For Hydraulic Research2016

Space and time reconstruction of the precessing vortex core in Francis turbine draft tube by 2D-PIV

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

Francis turbines operating at part load conditions experience the development of a high swirling flow at the runner outlet, giving rise to the development of a cavitation precessing vortex rope in the draft tube. The latter acts as an excitation source for ...

International Association For Hydraulic Research2016

Local wave speed and bulk flow viscosity in Francis turbines at part load operation

François Avellan, Christophe Nicolet, Andres Müller, Christian Landry, Arthur Tristan Favrel

The operation of Francis turbines at off-design conditions may cause the development of a cavitation vortex rope in the draft tube cone, acting as a pressure excitation source. The interactions between this excitation source and the hydraulic system at the ...

Taylor & Francis Ltd2016

Dynamics of the cavitation precessing vortex rope for Francis turbines at part load operating conditions

Arthur Tristan Favrel

The massive penetration of the existing electrical grid by renewable energy sources requires a continuous extension of the operating range of hydroelectric powerplants, which can lead to cavitation flow instabilities inducing undesirable mechanical vibrati ...

EPFL2016

Study of the vortex-induced pressure excitation source in a Francis turbine draft tube by particle image velocimetry

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

changes and loses its coherence, leading to a drastic reduction in the intensity of the induced excitation source. Francis turbines operating at part-load experience the development of a precessing cavitation vortex rope at the runner outlet, which acts as ...

Springer Verlag2015

Analysis of the part load helical vortex rope of a Francis turbine using on-board sensors

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

The cavitation helical vortex rope arising at Francis turbine partial load induces pressure fluctuations at the rope precession frequency, which can be decomposed into two components; the convective one and the synchronous one. The latter acts as an excita ...

Iop Publishing Ltd2015

Francis turbine draft tube modelling for prediction of pressure fluctuations on prototype

François Avellan, Christian Landry, Sébastien Alligné, Arthur Tristan Favrel

The prediction of pressure 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 research project Hy ...

Iop Publishing Ltd2015

On the physical mechanisms governing self-excited pressure surge in Francis turbines

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

The required operating range for hydraulic machines is continually extended in an effort to integrate renewable energy sources with unsteady power outputs into the existing electrical grid. The off-design operation however brings forth unfavorable flow pat ...

IOP Publishing Ltd2014

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, Andres Müller, Christian Landry, Arthur Tristan Favrel, 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

Experimental investigation of the local wave speed in a draft tube with cavitation vortex rope

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

Hydraulic machines operating in a wider range are subjected to cavitation developments inducing undesirable pressure pulsations which could lead to potential instability of the power plant. The occurrence of pulsating cavitation volumes in the runner and t ...

IOP Publishing Ltd2014

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

Iop Publishing Ltd2014

Experimental investigation of the local wave speed in a draft tube with cavitation vortex rope

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

Iop Publishing Ltd2014

Pressure measurements and high speed visualizations of the cavitation phenomena at deep part load condition in a Francis turbine

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

In a hydraulic power plant, it is essential to provide a reliable, sustainable and flexible energy supply. In recent years, in order to cover the variations of the renewable electricity production, hydraulic power plants are demanded to operate with more e ...

IOP Publishing Ltd2014

On the physical mechanisms governing self-excited pressure surge in Francis turbines

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

IOP science2014

Interaction of a pulsating vortex rope with the local velocity field in a Francis turbine draft tube

François Avellan, Andres Müller, Steven Roth, Christian Landry, Matthieu Dreyer, Alberto Bullani, Arthur Tristan Favrel

Acoustic resonances in Francis turbines often define undesirable limitations to their operating ranges at high load. The knowledge of the mechanisms governing the onset and the sustenance of these instabilities in the swirling flow leaving the runner is es ...

IOP science2013

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