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Parc éolien

Publications associées (251)

Large wind farms can destroy stratocumulus clouds-evidence from large eddy simulations.

Varun Sharma, Michael Lehning, Marc Parlange, Marc Calaf Bracons

Stratocumulus is one of the most common cloud types found in the atmospheric boundary layer (ABL) and have been shown to have a significant impact on modulating the global radiation and energy balance. In spite of their ubiquitousness however, their shallo ...

2018

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 ...

2018

From the Clouds to the Ground - Snow Precipitation Patterns in Complex Terrain

Varun Sharma, Michael Lehning, Alexis Berne, Franziska Gerber, Marco Gabella, Nikola Besic, Urs Martin Germann

Snow accumulation patterns are determined by many different processes from ice crystal nucleation in clouds to snow redistribution by wind and avalanches. In between, snow precipitation undergoes different dynamical and microphysical processes, such as ice ...

2018

Local snow transport and surface evolution processes in East Antarctica

Varun Sharma, Michael Lehning, Wolf Hendrik Huwald, Nander Wever, Francesco Comola, Eric Sauvageat, Philip Crivelli

In Antarctica, direct measurements of processes shaping the surface mass balance such as precipitation, accumulation and erosion, drifting and blowing snow, and sublimation, are sparse and challenging due to the extreme environment and related difficulties ...

2018

Interactions between drifting snow and surface dynamics

Philip Crivelli

In the cryosphere, the snow cover is the fastest changing component. Amongst other characteristics, the snow cover acts as a resource of water or has the ability to reflect the suns radiation and therefore significantly influence the climate on a global sc ...

EPFL2018

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

An experimental field study of the grounding system response of tall wind turbines to impulse surges

Marcos Rubinstein, Antonio Sunjerga, Nicolas Mora Parra

In this work, an experimental investigation of the grounding system behavior of tall wind turbines in both time and frequency domains is presented. Two scenarios were considered: in the first one, measurements were carried out on the grounding system embed ...

2018

Flow Adjustment Inside and Around Large Finite-Size Wind Farms

Fernando Porté Agel, Ka Ling Wu

In this study, large-eddy simulations are performed to investigate the flow inside and around large finite-size wind farms in conventionally-neutral atmospheric boundary layers. Special emphasis is placed on characterizing the different farm-induced flow r ...

2017

Wind farm density and harvested power in very large wind farms: A low-order model

Varun Sharma, Marc Calaf Bracons

In this work we create new understanding of wind turbine wakes recovery process as a function of wind farm density using large-eddy simulations of an atmospheric boundary layer diurnal cycle. Simulations are forced with a constant geostrophic wind and a ti ...

Amer Physical Soc2017

Flow adjustment inside large finite-size wind farms approaching the infinite wind farm regime

Fernando Porté Agel, Ka Ling Wu

Due to the increasing number and the growing size of wind farms, the distance among them continues to decrease. Thus, it is necessary to understand how these large finite-size wind farms and their wakes could interfere the atmospheric boundary layer (ABL) ...

2017

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