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

Publications associées (28)

Study of flexible operating conditions in variable-speed hydraulic turbines : advanced models and experimental validation

The global imperative to transition from fossil fuel-based energy sources to renewable alternatives has become increasingly urgent in the pursuit of sustainable and renewable power generation. This paradigm shift necessitates innovative approaches to manag ...

EPFL2024

On the prediction of the induced damage by the start-up sequence of Francis turbines: On operational resilience framework

Mario Paolone, Christophe Nicolet, Elena Vagnoni, Martin Seydoux

The number of transient operations in hydraulic machinery connected to power grid, notably start-ups and shut-downs, has observed a substantial increase in recent decades, primarily driven by the global shift toward intermittent renewable energy sources. S ...

Pergamon-Elsevier Science Ltd2024

Twenty years of irrigation acclimation is driven by denser canopies and not by plasticity in twig- and needle-level hydraulics in a Pinus sylvestris forest

Charlotte Grossiord, Christoph Bachofen, Eugénie Isabelle Mas, Alice Jacqueline Frédérique Gauthey, Alex Tunas Corzon

Climate change is predicted to increase atmospheric vapor pressure deficit, exacerbating soil drought, and thus enhancing tree evaporative demand and mortality. Yet, few studies have addressed the longer-term drought acclimation strategy of trees, particul ...

Oxford Univ Press2024

Enhancing Wind Farm Performance through Axial Induction and Tilt Control: Insights from Wind Tunnel Experiments

Fernando Porté Agel, Guillem Armengol Barcos

Static axial induction control and tilt control are two strategies that have the potential to increase power production in wind farms, mitigating wake effects and increasing the available power for downstream turbines. In this study, wind tunnel experiment ...

MDPI2024

Power performance of a model floating wind turbine subjected to cyclic pitch motion: A wind tunnel study

Fernando Porté Agel, Guiyue Duan, Daniele Gattari

Wind tunnel experiments were performed with a miniature floating wind turbine model to study the effects of cyclic pitch motion on its power performance. The cyclic pitch motion was prescribed by two key parameters: pitch frequency and amplitude. The power ...

IOPscience2024

Large-scale in-silico analysis of CSF dynamics within the subarachnoid space of the optic nerve

Gilles Fourestey

BackgroundImpaired cerebrospinal fluid (CSF) dynamics is involved in the pathophysiology of neurodegenerative diseases of the central nervous system and the optic nerve (ON), including Alzheimer's and Parkinson's disease, as well as frontotemporal dementia ...

BMC2024

Wind turbine wake superposition under pressure gradient

Fernando Porté Agel, Arslan Salim Dar

We investigate the effect of pressure gradient on the cumulative wake of multiple turbines in wind tunnel experiments spanning across a range of adverse pressure gradient (APG), zero pressure gradient (ZPG), and favorable pressure gradient (FPG). Compared ...

2024

Advanced control strategies to exploit the hydropower potential enhancing ancillary services provision to the power system

Francesco Gerini

The European Union's Green Deal aims for a 55% reduction in greenhouse gas emissions by 2030. To reach this goal, a massive integration of Renewable Energy Sources (RES) into the power grid is necessary. As RES become a large part of the electricity genera ...

EPFL2024

Towards an improved understanding of wind turbine wakes in complex terrain

Arslan Salim Dar

In this thesis, we explored the effect of certain terrain-induced flow phenomena on the development of wind turbines sited in complex terrain. A combined experimental and analytical approach is used to study wind turbine wakes in different types of complex ...

EPFL2024

The effect of nacelle-to-rotor size on the wake of a miniature wind turbine

Fernando Porté Agel, Arslan Salim Dar

Wind tunnel experiments are performed to investigate the effect of nacelle-to-rotor size on the wake of a wind turbine under different Reynolds numbers. Four different turbine configurations are tested, which vary in the rotor diameter and nacelle length a ...

IOP Science2024

Structural impact of the start-up sequence on Pelton turbines lifetime: Analytical prediction and polynomial optimization

Mario Paolone, Elena Vagnoni, Aldo Leonardo Alerci

Hydropower plants play a crucial role in the power system facing ambitious renewable energy targets. Due to their inherent controllability, they are well suited to provide flexibility to the grid. However, an increased flexibility provision leads to a prol ...

Pergamon-Elsevier Science Ltd2023

Fiber pumps for wearable fluidic systems

Herbert Shea, Vito Cacucciolo, Michael James Henry Smith

Incorporating pressurized fluidic circuits into textiles can enable muscular support, thermoregulation, and haptic feedback in a convenient wearable form factor. However, conventional rigid pumps, with their associated noise and vibration, are unsuitable f ...

American Association for the Advancement of Science2023

Addressing the challenges of homogeneity, quality control and waste handling in soil bio-cementation: A large-scale experiment

Lyesse Laloui, Dimitrios Terzis, Ray Harran

In an attempt to go beyond the conventional laboratory experiments widely reported in literature around the emerging technique of soil bio-cementation, this work addresses key challenges related to its large-scale application. Precisely, a state-of-the-art ...

JAPANESE GEOTECHNICAL SOC2023

The influence of the gas on the dynamics of cavitation bubbles

Davide Bernardo Preso

Cavitation bubbles, extensively investigated in fluid mechanics, present enduring challenges in hydraulic machinery, while holding considerable potential for practical applications in biomedicine and sonochemistry. Despite more than a century of research, ...

EPFL2023

Design, computational and experimental investigation of a small-scale turbopump for organic Rankine cycle systems

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

The hydraulic design, computational analysis, and experimental investigations of a high-speed small-scale turbopump for mobile waste heat recovery applications based on organic Rankine cycle systems are presented in this paper. Such applications demand hig ...

Elsevier2023

Interlocking modular microfluidic cooling substrates for future high energy physics experiments

Massimo Angeletti

In high energy physics, semiconductor-based sensors are widely used in particle tracking applications. These sensors are typically glued on low-mass cooling substrates, which guarantee the correct thermal management and, at the same time, minimise their in ...

EPFL2023

Enhancing Flood Resilience: Sediment Management in Le Bez Torrent

Giovanni De Cesare, Azin Amini, Romain Nathan Hippolyte Merlin Van Mol

In the canton of Bern, Switzerland, the “Le Bez” torrent is known for its flash floods, causing sediment and wood debris buildup in Villeret village settled on the alluvial fan. To mitigate this issue, a sediment/wood trap system is being implemented upstr ...

Swiss Academy of Sciences (SCNAT)2023

Research data supporting 'Fiber pumps for wearable fluidic systems'

Herbert Shea, Vito Cacucciolo, Michael James Henry Smith

The dataset supporting 'Fiber pumps for wearable fluidic systems', published in Science in March 2023. In this work, we present a fluidic pump in the form of a flexible and stretchable tube. These tubes - or 'fiber pumps' - can generate significant fluidic ...

2023

Dynamic stall characterisation and control for vertical-axis wind turbines

Sébastien Le Fouest

According to the International Energy Agency, the global net-zero emissions objective requires the installed wind power capacity to increase 11-fold between 2020 and 2050. The scientific community has recently voiced concerns about the logistic feasibility ...

EPFL2023

Cross-code verification of non-neutral ABL and single wind turbine wake modelling in LES

Fernando Porté Agel, Marwa Souaiby

Large Eddy Simulations (LES) of atmospheric boundary layer (ABL) flow with the actuator disc (AD) for turbine modelling is a widely used method of simulating wind farm flows. Hence, it is important to understand the requirements for achieving a good compar ...

IOP PUBLISHING LTD2023