Riwal Plougonven
PROFESSEUR CHARGÉ DE COURS

Riwal Plougonven has worked on atmospheric dynamics since his PhD at the Laboratoire de Météorologie Dynamique (1999-2002). He has been a post-doc at the National Center for Atmospheric Research in Boulder, Colorado, has been a lecturer at the University of St Andrews in Scotland. His main topics of research have been atmospheric dynamics and internal gravity waves, using theoretical, numerical and observational approaches. Since 2013 he has started working and teaching on wind energy, with a focus on wind forecasting.
CA/DER/DEP/MECA
MEC559 - Mechanics for Wind Energy, an introduction (2019-2020)
The main objective of this module will be to describe fundamental knowledge on the fluid mechanics of wind turbines (why do wind turbines look the way they do?) and on the fluid mechanics of the wind itself (what makes the wind blow?). Structural mechanics is also essential to the wind energy industry of course, and will also be addressed, but less in depth.
A second objective of this module will be to give an overview of the history of wind turbines, and to provide some elements on the present state and trends of wind energy in the world. These topics will be covered more concisely than those described above.
An originality of the course consists in presenting the fluid mechanics necessary for the understanding of both the flow around the turbine (aerodynamics) and the atmospheric flow which produces the boundary layer winds (geophysical fluid dynamics). This contrasts with standard texts on wind energy which generally describe the wind only from a statistical point of view.
Evaluation will take the form of a written exam.
------------------------
Le principal objectif du cours est d'aborder les aspects de mécanique pertinents pour comprendre l'utilisation du vent comme source d'énergie. Cela implique tout d'abord d'aborder l'aérodynamique pertinente pour décrire l'écoulement autour des pales en rotation et comprendre la structure et le dimensionnement des turbines. Cela implique aussi de considérer les efforts et les vibrations possibles des pales et de l'ensemble de la structure (mât et pales). Cela implique ensuite d'aborder de la mécanique des fluides géophysiques, pour comprendre ce qui détermine les caractéristiques du vent dans les basses couches de l'atmosphère, sa variabilité et sa prévisibilité.
Un objectif secondaire du cours sera de donner historique sur la production d'électricité à partir du vent et quelques éléments sur le contexte général des énergies renouvelables. Ces aspects seront abordés de manière plus concise que les aspects évoqués ci-dessus.
Une des originalités du cours sera de présenter à la fois les éléments de mécanique des fluides permettant d'aborder l'écoulement autour des turbines, et ceux permettant de comprendre la dynamique de l'atmosphère et l'origine des vents dans les basses couches. Ceci contraste avec ce qui est habituellement présenté dans des ouvrages sur l'éolien, où le vent n'est généralement décrit que de façon statistique, et considéré comme une donnée externe.
La génération d'électricité proprement dite (génératrices), les problèmes de raccordement aux réseaux et les aspects financiers de l'éolien ne seront pas abordés dans ce cours.
Langue du cours : Anglais
The main objective of this module will be to describe fundamental knowledge on the fluid mechanics of wind turbines (why do wind turbines look the way they do?) and on the fluid mechanics of the wind itself (what makes the wind blow?). Structural mechanics is also essential to the wind energy industry of course, and will also be addressed, but less in depth.
A second objective of this module will be to give an overview of the history of wind turbines, and to provide some elements on the present state and trends of wind energy in the world. These topics will be covered more concisely than those described above.
An originality of the course consists in presenting the fluid mechanics necessary for the understanding of both the flow around the turbine (aerodynamics) and the atmospheric flow which produces the boundary layer winds (geophysical fluid dynamics). This contrasts with standard texts on wind energy which generally describe the wind only from a statistical point of view.
Evaluation will take the form of a written exam.
------------------------
Le principal objectif du cours est d'aborder les aspects de mécanique pertinents pour comprendre l'utilisation du vent comme source d'énergie. Cela implique tout d'abord d'aborder l'aérodynamique pertinente pour décrire l'écoulement autour des pales en rotation et comprendre la structure et le dimensionnement des turbines. Cela implique aussi de considérer les efforts et les vibrations possibles des pales et de l'ensemble de la structure (mât et pales). Cela implique ensuite d'aborder de la mécanique des fluides géophysiques, pour comprendre ce qui détermine les caractéristiques du vent dans les basses couches de l'atmosphère, sa variabilité et sa prévisibilité.
Un objectif secondaire du cours sera de donner historique sur la production d'électricité à partir du vent et quelques éléments sur le contexte général des énergies renouvelables. Ces aspects seront abordés de manière plus concise que les aspects évoqués ci-dessus.
Une des originalités du cours sera de présenter à la fois les éléments de mécanique des fluides permettant d'aborder l'écoulement autour des turbines, et ceux permettant de comprendre la dynamique de l'atmosphère et l'origine des vents dans les basses couches. Ceci contraste avec ce qui est habituellement présenté dans des ouvrages sur l'éolien, où le vent n'est généralement décrit que de façon statistique, et considéré comme une donnée externe.
La génération d'électricité proprement dite (génératrices), les problèmes de raccordement aux réseaux et les aspects financiers de l'éolien ne seront pas abordés dans ce cours.
Langue du cours : Anglais
PHY206 - Waves in fluids, with examples from geophysics (2019-2020)
The course describes waves and heat transfer in fluids, with a preference for illustrations coming from the Earth system, in particular the atmosphere. Waves or oscillations are one essential type of motion present in many fluids. One goal of the course is to demonstrate how one proceeds to obtain wave solutions starting from a physical description of a system and its equations of motion. Acoustic waves will be considered as a first example, surface water waves at different scales (from ripples in the pond to tsunamis) will be derived as further examples. Basics of fluid mechanics (Euler equations, kinematics) will be introduced in order to make these developments possible. Similarities in the behavior of fluid waves and optical waves seen in PHY202 will be discussed.
The structure of the atmosphere and how we have progressively come to understand it will be reviewed. To describe this understanding and touch upon the subject of climate change, thermodynamics will be revisited and applied to the atmosphere (thermal structure, radiative balance).
At the end of the course, the students will understand how one characterizes a family of waves (dispersion relation, polarisation relations), and how to proceed to obtain, in a given system, wave solutions if they exist. The students will have reviewed thermodynamics and have seen applications to the atmosphere (thermal structure, atmospheric stability, clouds, radiative balance). Finally, some elements of the study of the Earth, and of the atmosphere in particular, will have been introduced.
MEC583 - Projects on Solar and Wind Energy: Resource and Performance Analysis (2019-2020)
Renewable energies (RE), such as solar photovoltaic (PV) and wind, are weather-driven and thus their outcome depends also on each location and time. Because of this, when evaluating the feasibility of a solar/wind plant, accurate information on local meteorological parameters is essential. In particular, local atmospheric measurements are valuable for two aspects: resource assessment and plant performance evaluation. Several kinds of projects are proposed within this module, mainly on the topics of resource assessment, but also on the mechanics of wind turbines. Models that describe the aerodynamics of a wind turbine, allow to estimate its efficiency, or the behavior of its components (blade, mast) can be explored.
Resource assessment and performance evaluation can be addressed within the RE platform of SIRTA’s atmospheric observatory at Ecole Polytechnique’s Campus. The project will make use of this platform and of the rich time series of measurements available. The following questions apply:
-Which are the instruments available for resource assessment for solar and wind energy?
-What are the variability of solar and wind resources at intra-daily, daily, monthly and annual scales?
-When evaluating the outdoors performance of a PV module, what are the impacts of temperature, solar irradiance, spectral distribution, tilt and orientation angles, solar shading and soiling?
-When anticipating the performance of a wind turbine, what are the impacts of roughness of the ground, the assumption on wind profile and wind speed distribution?
-What indicators exist to evaluate the performance for PV modules and wind turbines and what are expected and real found values?
Langue du cours : Anglais
Credits ECTS : 4
Renewable energies (RE), such as solar photovoltaic (PV) and wind, are weather-driven and thus their outcome depends also on each location and time. Because of this, when evaluating the feasibility of a solar/wind plant, accurate information on local meteorological parameters is essential. In particular, local atmospheric measurements are valuable for two aspects: resource assessment and plant performance evaluation. Several kinds of projects are proposed within this module, mainly on the topics of resource assessment, but also on the mechanics of wind turbines. Models that describe the aerodynamics of a wind turbine, allow to estimate its efficiency, or the behavior of its components (blade, mast) can be explored.
Resource assessment and performance evaluation can be addressed within the RE platform of SIRTA’s atmospheric observatory at Ecole Polytechnique’s Campus. The project will make use of this platform and of the rich time series of measurements available. The following questions apply:
-Which are the instruments available for resource assessment for solar and wind energy?
-What are the variability of solar and wind resources at intra-daily, daily, monthly and annual scales?
-When evaluating the outdoors performance of a PV module, what are the impacts of temperature, solar irradiance, spectral distribution, tilt and orientation angles, solar shading and soiling?
-When anticipating the performance of a wind turbine, what are the impacts of roughness of the ground, the assumption on wind profile and wind speed distribution?
-What indicators exist to evaluate the performance for PV modules and wind turbines and what are expected and real found values?
Langue du cours : Anglais
Credits ECTS : 4