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François Avellan

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Related publications (218)

Simulation of pump-turbine prototype fast mode transition for grid stability support

François Avellan, Christophe Nicolet, Nicolas Ruchonnet, Antoine Béguin, Olivier Braun

The paper explores the additional services that Full Size Frequency Converter, FSFC, solution can provide for the case of an existing pumped storage power plant of 2x210 MW, for which conversion from fixed speed to variable speed is investigated with a foc ...

2017

Toward design optimization of a Pelton turbine runner

François Avellan, Christian Vessaz, Christophe Tournier, Loïc Andolfatto

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

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

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

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

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

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

The erosion of a surface by a sediment-laden flow is an inherently multiscale phenomenon which includes physical interactions covering many orders of magnitude in both length and time scales. Conforming to the nature of the problem, we propose a novel mult ...

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

Experimental Hydro-Mechanical Characterization of Full Load Pressure Surge in Francis Turbines

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

Full load pressure surge limits the operating range of hydro-electric generating units by causing significant power output swings and by compromising the safety of the plant. It appears during the off-design operation of hydraulic machines, which is increa ...

2017

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

Experimental evidence of inter-blade cavitation vortex development in Francis turbines at deep part load condition

François Avellan, Arthur Tristan Favrel, Keita Yamamoto

Francis turbines are subject to various types of cavitation flow depending on the operating condition. To enable a smooth integration of the renewable energy sources, hydraulic machines are now increasingly required to extend their operating range, especia ...

Springer Verlag2017

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

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

2017

A GPU-accelerated versatile solver based on the finite volume particle method

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

2017

Exact finite volume particle method with spherical-support kernels

François Avellan, Christian Vessaz, Ebrahim Jahanbakhsh, Audrey Paulette Solange Maertens

The Finite Volume Particle Method (FVPM) is a meshless method for simulating fluid flows which includes many of the desirable features of mesh-based finite volume methods. In this paper, we develop a new 3-D FVPM formulation that features spherical kernel ...

Elsevier2017

On the sloshing free surface in the draft tube cone of a Francis turbine operating in synchronous condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto

Hydropower plants may be required to operate in synchronous condenser mode in order to supply reactive power to the grid for compensating the fluctuations introduced by the intermittent renewable energies such wind and solar. When operating in this mode, t ...

2017

Transposition of Francis turbine cavitation compliance at partial load to different operating conditions

François Avellan, Christian Landry, Joao Gomes Pereira Junior, Arthur Tristan Favrel

Francis turbines operating in part load conditions experience a swirling flow at the runner outlet leading to the development of a precessing cavitation vortex rope in the draft tube. This cavitation vortex rope changes drastically the velocity of pressure ...

2017

Comprehensive power loss modelling to improve the performance of an Energy Recovery Station for water utility networks

François Avellan, Cécile Münch-Alligné, Loïc Andolfatto, Daniel Biner

The work presented in this paper details the methodology applied to inventory and estimate the power losses in a micro-turbine with counter-rotating runners. The separation between the impact of design parameters and operational parameters on each identifi ...

Pennwell2017

On the Efficiency Alteration Mechanisms Due to Cavitation in Kaplan Turbines

François Avellan, Sebastián Camilo Leguizamón Sarmiento

A transport-equation-based homogeneous cavitation model previously assessed and validated against experimental data is used to investigate and explain the efficiency alteration mechanisms in Kaplan turbines. On the one hand, it is shown that the efficiency ...

2017

URANS Models for the Simulation of Full Load Pressure Surge in Francis Turbines Validated by Particle Image Velocimetry

François Avellan, Arthur Tristan Favrel

Due to the penetration of alternative renewable energies, the stabilization of the electrical power network relies on the off-design operation of turbines and pump-turbines in hydro-power plants. The occurrence of cavitation is however a common phenomenon ...

American Society of Mechanical Engineers2017

Part Load Vortex Rope as a Global Unstable Mode

François Avellan, Simon Pasche, François Gallaire

Renewable energy sources (RES) have reached 23.7% of the worldwide electrical generation production in 2015. The hydraulic energy contribution amounts to 16.6% and comes mainly form large-scale hydropower plants, where Francis turbines represents 60% of th ...

American Society of Mechanical Engineers2017

Fluid-structure interaction mechanisms leading to dangerous power swings in Francis turbines at full load

François Avellan, Christian Landry, Arthur Tristan Favrel

Hydropower plants play an important regulatory role in the large scale integration of volatile renewable energy sources into the existing power grid. This duty however requires a continuous extension of their operating range, provoking the emergence of com ...

Elsevier2017

Flow characteristics and influence associated with inter-blade cavitation vortices at deep part load operations of a Francis turbine

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

At a deep part load operation, Francis turbines are subject to the formation of inter-blade cavitation vortices inside blade channels, however its characteristics are not fully understood yet. The present study aims to investigate the development of the in ...

2017

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