Publications de Christian Landry

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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 ...

With the Energy Strategy 2050, Switzerland wishes to focus on balanced utilization of hydropower potentials and new renewable energy sources to cope with nuclear energy phasing out. Integration of large amounts of new renewable energies such as wind and so ...

At part load conditions, Francis turbines are subject to the emergence of a hydrodynamic instability in their draft tube, referred to as precessing vortex rope. It induces pressure pulsations in the water passages at the precession frequency of the vortex, ...

Hydraulic machines subject to off-design operation involve the presence of cavitating flow regimes in the draft tube. The cavitation vortex rope at part load conditions is described as an excitation source for the hydraulic system, and interactions between ...

Numerical simulation and stability analysis of an islanded power network comprising 40 MW of hydropower, 20 MW of wind power and 60 MW of gas-fired power plant are investigated. First, the modeling of each power plant is fully described. The wind farm is m ...

Nowadays, the pump-storage power plants are a proven solution for storing electricity at large scale and offering flexibility to the power management. Therefore, the hydraulic machines are increasingly subject to off-design operation, start-up and shutdown ...

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 ...

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 ...

At part load operation, Francis turbines experience the development of a cavitation vortex rope in the draft tube, whose precession acts as a pressure excitation source. In case of resonance, the resulting pressure pulsations lead to unacceptable torque an ...

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 ...

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 ...

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 ...

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 ...

In real systems, the phenomena, such as pipe-wall viscoelasticity, unsteady friction or fluid structure interaction induce additional damping and dispersion of transient pressure waves than that defined by classical waterhammer. In this paper, unsteady fri ...

Christian Landry

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

Renovation of hydraulic power plant: how to select the best technical options?

Swirl number based transposition of flow-induced mechanical stresses from reduced scale to full-size Francis turbine runners

Hydroacoustic Modeling of a Cavitation Vortex Rope for a Francis Turbine

Influence of the Hydraulic System Layout on the Stability of a Mixed Islanded Power Network

Non-Linear Stability Analysis of a Reduced Scale Model Pump-Turbine at Off-Design Operation

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

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

New insight in Francis turbine cavitation vortex rope: role of the runner outlet flow swirl number

Hydro-acoustic resonance behavior in presence of a precessing vortex rope: observation of a lock-in phenomenon at part load Francis turbine operation

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

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

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

Modeling of Unsteady Friction and Viscoelastic Damping in Piping Systems