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Concept

Vent géostrophique

Publications associées (18)

Information-Driven Gas Distribution Mapping for Autonomous Mobile Robots

Alcherio Martinoli, Faezeh Rahbar, Chiara Ercolani

The ability to sense airborne pollutants with mobile robots provides a valuable asset for domains such as industrial safety and environmental monitoring. Oftentimes, this involves detecting how certain gases are spread out in the environment, commonly refe ...

MDPI2023

Exploring the coupled ocean and atmosphere system with a data science approach applied to observations from the Antarctic Circumnavigation Expedition

Julia Schmale, Katherine Colby Leonard, Andrea Baccarini, Robin Lewis Modini, Sebastian Johannes Heinz-Josef Landwehr, Alireza Moallemi, Fernando Perez Cruz, Christel Sybille Hassler

The Southern Ocean is a critical component of Earth's climate system, but its remoteness makes it challenging to develop a holistic understanding of its processes from the small scale to the large scale. As a result, our knowledge of this vast region remai ...

2021

Emergence of representative signals for sudden stratospheric warmings beyond current predictable lead times

Guillaume Romain Obozinski, Raphaël Gérard Théodore Michel Marie de Deloÿe et Fourcade de Fondeville

Major sudden stratospheric warmings (SSWs) are extreme wintertime circulation events of the Arctic stratosphere that are accompanied by a breakdown of the polar vortex and are considered an important source of predictability of tropospheric weather on subs ...

Copernicus Gesellschaft Mbh2021

Numerical Experiments of Atmospheric Boundary Layer flows : interplay between distributed drag elements and buoyancy effects

Varun Sharma

Anthropogenic emissions of greenhouse gases due to human activity is causing global warming and inducing climate change. A major implication of global warming is the decreasing ice mass in the polar regions resulting in sea-level rise. It is now known that ...

EPFL2018

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

Perturbations to the Spatial and Temporal Characteristics of the Diurnally-Varying Atmospheric Boundary Layer Due to an Extensive Wind Farm

Marc Parlange, Varun Sharma, Marc Calaf Bracons

The effect of extensive terrestrial wind farms on the spatio-temporal structure of the diurnally-evolving atmospheric boundary layer is explored. High-resolution large-eddy simulations of a realistic diurnal cycle with an embedded wind farm are performed. ...

Springer Verlag2017

Flow boiling and frictional pressure gradients in plate heat exchangers. Part 1: Review and experimental database

John Richard Thome, Raffaele Luca Amalfi, Farzad Vakili Farahani

This two-part paper presents an overview of evaporation heat transfer mechanisms, a review of the experimental and prediction methods and a creation of a consolidated multi-lab database of 3601 data points and provides a detailed comparison of all the pred ...

Elsevier Sci Ltd2016

Influence of the Coriolis force on the structure and evolution of wind turbine wakes

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation combined with a turbine model is used to investigate the effect of vertical wind veer associated with the Coriolis force on the structure and evolution of wind turbine wakes. In order to isolate the Coriolis effect on t ...

Amer Physical Soc2016

High resolution local heat transfer and pressure drop infrared measurements of two-phase flow of R245fa within a compact plate heat exchanger

John Richard Thome, Raffaele Luca Amalfi

An experimental study is presented to characterize two-phase thermal and hydraulic performance of a prototype corrugated plate heat exchanger with small pressing depth. In particular, upward flow boiling of low pressure refrigerant R245fa was investigated ...

Pergamon-Elsevier Science Ltd2016

Boiling heat transfer and two-phase pressure drops within compact plate heat exchangers: Experiments and flow visualizations

John Richard Thome, Raffaele Luca Amalfi

Infrared (IR) thermography was used to measure the local heat transfer coefficients within two plate heat exchanger geometries. The chevron patterns were machined into polycarbonate and IR transparent calcium fluoride plates, both of which were electricall ...

Pergamon-Elsevier Science Ltd2016

Flow boiling and frictional pressure gradients in plate heat exchangers. Part 2: Comparison of literature methods to database and new prediction methods

John Richard Thome, Raffaele Luca Amalfi, Farzad Vakili Farahani

In the second part of this study a sensitivity analysis on the prediction methods is performed to consider the effect of plate geometry on thermal hydraulic performance and an extensive comparison of all the two-phase pressure drop and flow boiling heat tr ...

Elsevier Sci Ltd2016

Time-adaptive wind turbine model for an LES framework

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

Most large-eddy simulation studies related to wind energy have been carried out either by using a fixed pressure gradient to ensure that mean wind direction is perpendicular to the wind turbine rotor disk or by forcing the flow with a geostrophic wind and ...

Wiley-Blackwell2015

Atmospheric Flow Development and Associated Changes in Turbulent Sensible Heat Flux over a Patchy Mountain Snow Cover

Michael Lehning

In this study, the small-scale boundary layer dynamics and the energy balance over a fractional snow cover are numerically investigated. The atmospheric boundary layer flows over a patchy snow cover were calculated with an atmospheric model (Advanced Regio ...

Amer Meteorological Soc2015

3D Turbulence Measurements Using Three Synchronous Wind Lidars: Validation against Sonic Anemometry

Fernando Porté Agel, Giacomo Valerio Iungo, Fernando Carbajo Fuertes

This paper presents a technique to measure the time series of the three components of the wind vector at a point in space from synchronous measurements of three scanning Doppler wind lidars. Knowing the position of each lidar on the ground and the orientat ...

Amer Meteorological Soc2014

Two-phase frictional pressure drops in U-bends and contiguous straight tubes for different refrigerants, orientations, tube, and bend diameters: Part 1. Experimental results (RP-1444)

John Richard Thome, Ricardo Lima

Over the years, much research has been conducted on two-phase flows in straight tubes because these tend, in length, to be predominant in two-phase systems. However, two-phase heat exchangers can also have singularity elements, where the most common type i ...

Taylor & Francis Inc2012

Prediction of the entrained liquid fraction in vertical annular gas–liquid two-phase flow

John Richard Thome, Andrea Cioncolini

The study considers the prediction of the entrained liquid fraction in adiabatic gas-liquid annular two-phase flow in vertical pipes. Nine empirical correlations have been tested against an experimental data bank drawn together in this study containing 150 ...

Elsevier2010

Impact of Surface Flux Formulations and Geostrophic Forcing on Large-Eddy Simulations of Diurnal Atmospheric Boundary Layer Flow

Marc Parlange

The impact of surface flux boundary conditions and geostrophic forcing on multiday evolution of flow in the atmospheric boundary layer (ABL) was assessed using large-eddy simulations (LES). The LES investigations included several combinations of surface bo ...

American Meteorological Society2010

Two-Phase Pressure Drops in Adiabatic Horizontal Circular Smooth U-Bends and Contiguous Straight Pipes (RP-1444)

John Richard Thome, Ricardo Lima

Curved channels in the form of bends are encountered in many industrial two-phase flow applications, such as U-bends in air-conditioning and refrigeration evaporators and condensers. For engineering design purposes, the evaluation of the pressure loss in t ...

2010