Publications de Nicolas Ruchonnet

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

A statistical method for draft tube pressure pulsation analysis

Nicolas Ruchonnet

Draft tube pressure pulsation (DTPP) in Francis turbines is composed of various components originating from different physical phenomena. These components may be separated because they differ by their spatial relationships and by their propagation mechanis ...

International Association For Hydraulic Research2012

Cavitation influence on hydroacoustic resonance in pipe

François Avellan, Christophe Nicolet, Sébastien Alligné, Nicolas Ruchonnet

In pipe systems, pressure and flow fluctuations below cutoff frequency propagate as plane waves along pipes. Depending on the pipe length and propagation velocity, resonance leading to high amplitude pressure fluctuation may occur. At low pressure, cavitat ...

Elsevier2012

Hydroacoustic Simulation of Rotor-Stator Interaction in Resonance Conditions in Francis Pump-Turbine

François Avellan, Christophe Nicolet, Sébastien Alligné, Nicolas Ruchonnet

Combined effect of rotating pressure field related to runner blade and wakes of wicket gates leads to rotor stator interactions, RSI, in Francis pump-turbines. These interactions induce pressures waves propagating in the entire hydraulic machine. Superposi ...

International Association For Hydraulic Research2010

Multiscale Computational Methodology Applied to Hydroacoustic Resonance in Cavitating Pipe Flow

Nicolas Ruchonnet

The present work is a contribution to the physical analysis and numerical simulation of the pressure surges in hydraulic machinery and connected conduit systems. Localized hydrodynamic instabilities including cavitation are prone to interact with the entir ...

EPFL2010

Numerical Simulation of Nonlinear Self Oscillations of a Full Load Vortex Rope

François Avellan, Christophe Nicolet, Pierre Maruzewski, Sébastien Alligné, Vlad Hasmatuchi, Nicolas Ruchonnet

Self excited instabilities or oscillations of a cavitating full load vortex rope occur due to an interaction between the gas volume and the acoustic waves. From the onset of the oscillations, the amplitudes grow until they reach a maximum, called the “limi ...

2009

One-Dimensional Modeling of Rotor Stator Interaction in Francis Pump-Turbine

François Avellan, Christophe Nicolet, Nicolas Ruchonnet

A one-dimensional hydroacoustic model is set up to perform the numerical simulation of the rotor-stator interaction of a Francis pump-turbine scaled model. The numerical results enable to identify both rotating diametrical modes in the vaneless gap between ...

International Association For Hydraulic Research2006

Hydroacoustic Modeling of Rotor Stator Interaction in Francis Pump-Turbine

François Avellan, Christophe Nicolet, Nicolas Ruchonnet

A one-dimensional hydroacoustic model is set up to perform the numerical simulation of the rotor-stator interaction of a Francis pump-turbine scaled model. The numerical results enable to identify both rotating diametrical modes in the vaneless gap between ...

2006

One-Dimensional Modeling of Rotor Stator Interaction in Francis Pump-Turbine

François Avellan, Christophe Nicolet, Nicolas Ruchonnet

A one-dimensional hydroacoustic model is set up to perform the numerical simulation of the rotor-stator interaction of a Francis pump-turbine scaled model. The numerical results enable to identify both rotating diametrical modes in the vaneless gap between ...

2006