Publications related to Wind engineering

Correlation of powers of Hüsler-Reiss vectors and Brown-Resnick fields, and application to insured wind losses

H & uuml;sler-Reiss vectors and Brown-Resnick fields are popular models in multivariate and spatial extreme-value theory, respectively, and are widely used in applications. We provide analytical formulas for the correlation between powers of the components ...

Springer2024

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

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

Power Production and Blade Fatigue of a Wind Turbine Array Subjected to Active Yaw Control

Fernando Porté Agel, Mou Lin

This study investigated the power production and blade fatigue of a three-turbine array subjected to active yaw control (AYC) in full-wake and partial-wake configurations. A framework of a two-way coupled large eddy simulation (LES) and an aeroelastic blad ...

MDPI2023

Earwig-inspired foldable origami wing for micro air vehicle gliding

Jamie Paik, Risa Ishiguro

Foldable wings serve as an effective solution for reducing the size of micro air vehicles (MAVs) during non-flight phases, without compromising the gliding capacity provided by the wing area. Among insects, earwigs exhibit the highest folding ratio in thei ...

Frontiers Media Sa2023

Deep Q-learning agent for building earthquake resisting wall

Katrin Beyer, Qianqing Wang, Ketson Roberto Maximiano Dos Santos

The construction of dry-joint brick masonry that is subject to seismic loading can be modelled as a strategy problem wherein bricks must be laid to form a load resisting structure. To learn how to mount bricks while considering relevant engineering criteri ...

2022

Wind farm layout and unconstrained hub height optimization using genetic algorithms applied to different power densities

Fernando Porté Agel, Nicolas Otto Kirchner Bossi

LES and wind tunnel studies have shown significant benefit when allowing turbines (T) in a wind farm to adopt different heights. This work presents two new genetic algorithms (GA) that perform wind farm layout optimization (WFLO) involving continuous and t ...

2022

Broadband Quasi-Phase-Matching in All-Optically Poled Stoichiometric Silicon Nitride Waveguides

Camille Sophie Brès, Boris Zabelich, Edgars Nitiss

We show how broadband (>30nm) quasi-phase matching in all-optically poled Si3N4 waveguides provides a platform for efficient sum-frequency generation, and for femtosecond pulse processing such as fcEo detection without the need for group velocity engineeri ...

IEEE2020

Spatiotemporal dynamics of snow erosion, deposition and horizontal mass flux

Michael Lehning, Enrico Paterna, Philip Crivelli

The quantification of snow transport, both in wind tunnels and the field, apply particle counting methods limited to punctual sampling of relatively small volumes. Particle counting can only capture horizontal mass fluxes, failing to measure snow erosion o ...

2019

Characterization of Wind Turbine Wakes with Nacelle-Mounted Doppler LiDARs and Model Validation in the Presence of Wind Veer

Fernando Porté Agel, Peter Andreas Brugger, Fernando Carbajo Fuertes, Corey Dean Markfort, Mohsen Vahidzadeh

Accurate prediction of wind turbine wakes is important for more efficient design and operation of wind parks. Volumetric wake measurements of nacelle-mounted Doppler lidars are used to characterize the wake of a full-scale wind turbine and to validate an a ...

2019

Linearity versus non-linearity in high frequency multilevel wind time series measured in urban areas

Dasaraden Mauree, Fabian Guignard, Mohamed Laib

In this paper, high frequency wind time series measured at different heights from the ground (from 5.5 to 25.5 meters) in an urban area were investigated. The spectrum of each series is characterized by a power-law behaviour at low frequency range, with a ...

2019

Experimental investigation of vertical-axis wind-turbine wakes in boundary layer flow

Fernando Porté Agel, Vincent François-Charles Rolin

In this experiment, a small scale vertical-axis wind-turbine (VAWT) is immersed in a boundary-layer in a wind tunnel and stereo particle image velocimetry is employed to quantify the 3D characteristics of the wake. The measurements show that the wake is st ...

Pergamon-Elsevier Science Ltd2018

Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation

Julien Dominique Claude Deparday

This work presents a wind tunnel experimental study on the effect of the leading edge flapping on the aerodynamic performance of a spinnaker. Four J80-class spinnaker models, combining two different assembling structures (panel layout) and two different sa ...

PERGAMON-ELSEVIER SCIENCE LTD2018

Wind-packing of snow: How do wind crusts form?

Christian Gabriel Sommer

Wind-packing of snow is the process responsible for the formation of wind slabs and wind crusts. These are hard layers of well-sintered snow often found in the snowpack in mountains as well as in polar regions. Wind-packing affects the local mass balance, ...

EPFL2018

Aeroelastic deformation of a perforated strip

Pedro Miguel Nunes Pereira de Almeida Reis, Mark Andrew Guttag

We perform a combined experimental and numerical investigation into the static deformation of perforated elastic strips under uniform aerodynamic loading at high-Reynolds-number conditions. The static shape of the porous strips, clamped either horizontally ...

2018

Long-term monitoring of existing wind turbine towers and fatigue performance of UHPFRC under compressive stresses

Christophe Thierry Loraux

An increasing number of onshore wind turbines in Europe will reach the end of their relatively short service duration, currently limited to 20 years by the design codes and many owners already wish to extend the service duration of their turbines. Recently ...

EPFL2018

Active aerodynamic drag reduction on morphable cylinders

Pedro Miguel Nunes Pereira de Almeida Reis, Mark Andrew Guttag

We study a mechanism for active aerodynamic drag reduction on morphable grooved cylinders, whose topography can be modified pneumatically. Our design is inspired by the morphology of the Saguaro cactus (Carnegiea gigantea), which possesses an array of axia ...

2017

Optimal solution and asymptotic properties of a stochastic control problem arising in sailboat trajectory optimization

Carlo Ciccarella

We study the optimal strategy for a sailboat to reach an upwind island under the hypothesis that the wind direction fluctuates according to a Brownian motion and the wind speed is constant. The work is motivated by a concrete problem which typically arises ...

EPFL2017

Mitigation of Wind-Induced Vibrations in Long-Span Bridges using a Distributed Flap System

Klara Maria Boberg

Since the collapse of the Tacoma Narrows Bridge more than 70 years ago suppressing wind-induced instabilities has been a key aspect of the design of long-span bridges. The intensive experimental and theoretical research in wind engineering allowed research ...

EPFL2016

Seismic behaviour and analysis of U-shaped RC walls

Raluca-Tereza Constantin

In many countries of moderate to high seismicity, reinforced concrete (RC) core walls are used as lateral bracing systems in mid- to high-rise buildings where they typically accommodate lift shafts or stair cases. Unlike planar walls which provide horizont ...

EPFL2016