Publications associées à Innovative measurement techniques for atmospheric turbulence and wind energy

Publications associées (32)

Conditions for the local arrest of a hydraulic fracture by a region of larger toughness

We investigate the conditions for the local arrest of a hydraulic fracture encountering a region of larger toughness. The propagation of a hydraulic fracture strongly depends on the ratio between the energy dissipated in the creation of new fracture surfac ...

ASME International2025

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

On the Perspectives of Image-to-Lidar Constraints in Dynamic Network Optimisation

Thibaut Stoltz, Jan Skaloud, Davide Antonio Cucci, Laurent Valentin Jospin, Kyriaki Mouzakidou

The evolution of airborne mapping witnesses the introduction of hybrid lidar-camera systems to enhance data collection, i.e. to obtain simultaneously high-density point-cloud and texture. Yet, the common adjustment of both optical data streams is a nontriv ...

International Society for Photogrammetry and Remote Sensing2025

Turbulence and Heat exchange in the Near-Surface Boundary Layer over Patchy Snow

Michael Haugeneder

The atmospheric layer adjacent to the earth's surface is of crucial importance for weather models due to the exchange of energy between the surface and the atmosphere. This exchange is dependent on the various surface properties and influences the state of ...

EPFL2024

Buoyancy-tilted Shear Layers and Coherent Structures in Hyperpycnal River Plume Plunging

David Andrew Barry, Ulrich Lemmin, Haoran Shi

Shear layers and corresponding Kelvin Helmholtz-type Coherent Structures (KHCS) can be generated by rivers discharging into laterally-unconfined quiescent open water bodies (e.g., lakes). When the river discharge has a greater density than the receiving wa ...

AMER GEOPHYSICAL UNION2025

Factor-graph Optimisation with Vehicle Dynamic Models for Mapping & Sensing Applications

Kenneth Joseph Paul

Unmanned vehicles have become indispensable tools in various fields such as agriculture, environmental monitoring, and disaster response. A crucial component of these platforms is sensor fusion. As measurements are inherently noisy, certain variables canno ...

EPFL2025

Observations of high-time-resolution and size-resolved aerosol chemical composition and microphysics in the central Arctic: implications for climate-relevant particle properties

Julia Schmale, Andrea Baccarini, Ivo Fabio Beck, Hélène Paule Angot, Lubna Dada, Jakob Boyd Pernov, Benjamin Jérémy Laurent Heutte, Nora Bergner, Markus Frey

Aerosols play a critical role in the Arctic's radiative balance, influencing solar radiation and cloud formation. Limited observations in the central Arctic leave gaps in understanding aerosol dynamics year-round, affecting model predictions of climate-rel ...

Copernicus GmbH2025

Improvements to the dynamic wake meandering model by incorporating the turbulent Schmidt number

Fernando Porté Agel, Peter Andreas Brugger, Corey Dean Markfort

Predictions of the dynamic wake meandering model (DWMM) were compared to flow measurements of a scanning Doppler lidar mounted on the nacelle of a utility-scale wind turbine. We observed that the wake meandering strength of the DWMM agrees better with the ...

2024

Snowfall deposition in mountainous terrain: a statistical downscaling scheme from high-resolution model data on simulated topographies

Michael Lehning

One of the primary causes of non-uniform snowfall deposition on the ground in mountainous regions is the preferential deposition of snow, which results from the interaction of near-surface winds with topography and snow particles. However, producing high-r ...

Frontiers Media Sa2024

Characterization of Hydraulic Rock Diffusivity Using Oscillatory Pore Pressure

Dario Sciandra

The interest of exploring deep geological resources for energy-related activities is rapidly increasing. Lowering the risks associated with these activities requires the development of fast and accurate in situ rock characterization methods. Monitoring and ...

Springer Science and Business Media LLC2025

Understanding snow saltation parameterizations: lessons from theory, experiments and numerical simulations

Michael Lehning, Armin Sigmund, Daniela Brito Melo

Drifting and blowing snow are important features in polar and high mountain regions. They control the surface mass balance in windy conditions and influence sublimation of snow and ice surfaces. Despite their importance, model representations in weather an ...

2024

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

An improved statistical wake meandering model

Fernando Porté Agel, Corey Dean Markfort, Peter Andreas Brugger

A new statistical wake meandering (SWM) model is proposed that improves on existing models in the literature. Compared to the existing SWM models, the proposed model has a closed description that does not require simulations to create look-up tables while ...

IOP Publishing2024

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

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

Mean-field transport equations and energy theorem for plasma edge turbulent transport

Reinart Andreas J. Coosemans

This paper establishes a mean-field equation set and an energy theorem to provide a theoretical basis in view of the development of self-consistent, physics-based turbulent transport models for mean-field transport codes. A rigorous averaging procedure ide ...

Cambridge University Press2024

An improved analytical framework for flow prediction inside and downstream of wind farms

Marwa Souaiby, Fernando Porté Agel

This study evaluates available analytical wake models for flow prediction inside and downstream of wind farms of different sizes and layouts using large-eddy simulation (LES), and introduces an enhanced analytical framework. All the tested analytical wake ...

Pergamon-Elsevier Science Ltd2024

Non-contact sensing for anomaly detection in wind turbine blades: A focus-SVDD with complex-valued auto-encoder approach

Olga Fink, Gaëtan Michel Frusque

The occurrence of manufacturing defects in wind turbine blade (WTB) production can result in significant increases in operation and maintenance costs of WTBs, reduce capacity factors of wind farms, and occasionally lead to severe and disastrous consequence ...

2024

Optimal blade pitch control for enhanced vertical-axis wind turbine performance

Karen Ann J Mulleners, Sébastien Le Fouest

Vertical-axis wind turbines are great candidates to enable wind power extraction in urban and off-shore applications. Currently, concerns around turbine efficiency and structural integrity limit their industrial deployment. Flow control can mitigate these ...

Nature Research2024

Gaia's brightest very metal-poor (VMP) stars Metallicity catalogue of a thousand VMP stars from Gaia's radial velocity spectrometer spectra

Nicolas Lawrence Etienne Longeard

Context. Gaia DR3 has offered the scientific community a remarkable dataset of approximately one million spectra acquired with the radial velocity spectrometer (RVS) in the calcium II triplet region, which is well suited to identify very metal-poor (VMP) s ...

Edp Sciences S A2024