Publication

Similarity of cavitation inception in Francis turbines

Publications associées (33)

An experimental study on the upper part-load elliptical vortex instability in a Francis turbine

François Avellan, Elena Vagnoni, Arthur Tristan Favrel, Andres Müller, Ali Amini

This paper presents preliminary results of an experimental study on the occurrence and development of the upper part-load instability in a reduced-scale Francis turbine. The study includes draft tube pressure measurements, high-speed flow visualization, an ...

IOP PUBLISHING LTD2021

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, Christian Landry, Sébastien Alligné, Joao Gomes Pereira Junior

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

Dynamic modal analysis during reduced scale model tests of hydraulic turbines for hydro-acoustic characterization of cavitation flows

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

Francis turbines operating at off-design conditions experience the development of unfavourable cavitation flows in the draft tube at the runner outlet, which induce pressure pulsations and hydro-acoustic resonances in the worst cases. The assessment of hyd ...

2019

Two-phase flow phenomena in hydraulic turbines and pump-turbines operating in synchronous condenser mode

Elena Vagnoni

Hydraulic turbines and pump-turbines are often required to operate in particular conditions at which they consume active power. To keep the power consumption at a minimum, it is necessary to dewater the runner to reduce the mechanical torque. One of these ...

EPFL2018

Measurements of Cavitation Compliance in the Draft Tube Cone of a Reduced Scale Francis Turbine Operating at Part Load

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

Francis turbines operating at part load conditions typically experience a cavitation vortex rope immediately at the runner outlet. As the compliance of this cavitation flow is much higher than the one in cavitation-free conditions, a decrease in the value ...

2018

RANS computations of a confined cavitating tip-leakage vortex

Mohamed Farhat, Matthieu Dreyer

Cavitating tip-leakage vortices appear in several hydrodynamic flows such as marine propellers or Kaplan turbines. Cavitating computations are a challenging topic since several keys issues are an ongoing work such as the definition of a universal mass sour ...

2018

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

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

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

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

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