


Registros recuperados: 22  


Mycek, Paul; Pinon, Gregory; Germain, Gregory; Rivoalen, Elie. 
The modelling of diffusive terms in particle methods is a delicate matter and several models have been proposed in the literature. The Diffusion Velocity Method (DVM) consists in rewriting these terms in an advective way, thus defining a socalled diffusion velocity. In addition to the actual velocity, it is used to compute the particles displacement. On the other hand, the wellknown and commonly used Particle Strength Exchange method (PSE) uses an approximation of the Laplacian operator in order to model diffusion. This approximation is based on an exchange of particles strength. Although DVM is particularly well suited to particle methods since it preserves their Lagrangian aspect, its major drawback stems in the fact that it suffers from severe... 
Tipo: Text 
Palavraschave: Particle method; Diffusion; DVM; PSE. 
Ano: 2013 
URL: http://archimer.ifremer.fr/doc/00159/27006/25254.pdf 
 

 


Carlier, Clement; Pinon, Gregory; Gaurier, Benoit; Germain, Gregory; Rivoalen, Elie. 
The ambient turbulence intensity is a key factor in the study of marine current turbines. Indeed recent studies have shown that ambient turbulence intensity highly modifies the behavior of horizontal axis marine current turbines. Consequently numerical simulations have to represent the ambient turbulence or at least its effects on the performance and wake of the turbines. This paper presents the latest numerical developments carried out at LOMC in collaboration with IFREMER in order to take into account the effects of ambient turbulence. 
Tipo: Text 

Ano: 2015 
URL: http://archimer.ifremer.fr/doc/00252/36293/34822.pdf 
 


Maganga, Fabrice; Germain, Gregory; Facq, Jeanvalery; Gaurier, Benoit; Rivoalen, Elie; Pinon, Grégory. 
Le fonctionnement d’une hydrolienne est régi par les caractéristiques de l’écoulement incident. Cet article présente les résultats d’une étude expérimentale visant à déterminer les effets du taux de turbulence de l’écoulement ambiant sur le fonctionnement d’une hydrolienne et le sillage généré. Les essais expérimentaux ont été réalisés dans la veine hydrodynamique à surface libre de l’Ifremer, dont on peut faire varier le taux de turbulence de l’écoulement de 5 à 25%. Le prototype utilisé est une turbine tripales à axe horizontal de 0,7 m de diamètre (échelle 1/30). Des cartes de vitesses moyennes, de taux de turbulence, mais également d’énergie cinétique turbulente et de contrainte de cisaillement ont été obtenus à partir de mesures par vélocimétrie... 
Tipo: Text 

Ano: 2010 
URL: http://archimer.ifremer.fr/doc/00022/13355/10386.pdf 
 


Carlier, Clement; Pinon, Gregory; Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Rivoalen, Elie. 
The development of marine current turbines arrays still needs nowadays many studies among which we can find the study of interactions between devices. In order to highlight these interactions effects, experiments were carried out in the IFREMER’s (BoulognesurMer) flume tank. Those experiments used 3bladed horizontal axis marine current turbines prototypes, regulated in rotation speed. To complete these experiments, a threedimensional numerical tool is developed at the LOMC (Université du Havre) to simulate one or more turbines in a free upstream current. We present hereafter the numerical and experimental results obtained in the scope of the study of elementary interaction between two turbines axially aligned with the upstream current. 
Tipo: Text 

Ano: 2014 
URL: http://archimer.ifremer.fr/doc/00247/35806/34320.pdf 
 


Mycek, Paul; Pinon, Gregory; Germain, Gregory; Rivoalen, Elie; Gaurier, Benoit. 
Developments of new marine current turbines farm are subject to a better understanding of interactions effects between the turbines. Experimental trials have been realised in the wave and current flume of IFREMER BoulognesurMer, on a three bladed horizontal axis marine current turbine in order to characterise the elementary interaction between two turbines aligned with the current. At the same time, a threedimensional numerical software has been developed in order to model the flow behind a marine current turbine. The software is based on a Lagrangian Vortex Method. It enables to evaluate the forces and moments onto the rotor as well as the flow fields around the turbine. Most of the previous numerical studies regarding interaction between devices only... 
Tipo: Text 

Ano: 2012 
URL: http://archimer.ifremer.fr/doc/00141/25200/23360.pdf 
 


Carlier, Clement; Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Pinon, Gregory; Rivoalen, Elie. 
Le développement de fermes d'hydroliennes a suscité et suscite toujours de nombreuses études parmi lesquelles figure l’étude des effets d'interactions entre les machines. Afin de comprendre ces effets d'interactions des essais expérimentaux ont été effectués dans un bassin à houle et courant sur des maquettes d’hydroliennes 3 pales à axe horizontal, régulées en vitesse de rotation. Ces essais portent sur la caractérisation du fonctionnement d’une, puis de deux hydroliennes alignées avec le courant à partir de mesure de performance et de sillage. En parallèle, un code numérique tridimensionnel est développé pour modéliser une ou plusieurs hydroliennes dans un écoulement. On présente ici les résultats numériques et expérimentaux, obtenus pour deux points de... 
Tipo: Text 
Palavraschave: Energies marine; Hydroliennes; Simulation numérique; Méthode vortex; Méthode lagrangienne; Essais expérimentaux. 
Ano: 2014 
URL: http://archimer.ifremer.fr/doc/00212/32341/30781.pdf 
 

 


Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Pinon, Gregory; Rivoalen, Elie. 
The ambient turbulence intensity in the upstream flow plays a decisive role in the behaviour of horizontal axis marine current turbines. Experimental trials, run in the IFREMER flume tank in BoulogneSurMer (France) for two different turbulence intensity rates, namely 3% and 15%, are presented. They show, for the studied turbine configuration, that while the wake of the turbine is deeply influenced by the ambient turbulence conditions, its mean performances turn out to be slightly modified. The presented conclusions are crucial in the view of implanting second generation turbines arrays. In addition, complete and detailed data sets (wake profiles and performance graphs) are made available to the scientific community in order to encourage further... 
Tipo: Text 
Palavraschave: Marine current turbine; Performance; Wake; Turbulence; Experiment; Flume tank. 
Ano: 2014 
URL: http://archimer.ifremer.fr/doc/00175/28647/27171.pdf 
 


Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Pinon, Gregory; Rivoalen, Elie. 
The future implantation of second generation marine current turbine arrays depends on the understanding of the negative interaction effects that exist between turbines in close proximity. This is especially the case when the turbines are axially aligned one behind another in the flow. In order to highlight these interaction effects, experiments were performed in a flume tank on 3bladed 1/30th scale prototypes of horizontal axis turbines. This work focuses on the interactions between two horizontal axis marine current turbines, axially aligned with the upstream flow. Thrust and power coefficients function of the rotation speed of the downstream device are presented. Besides, the wake of each turbine is characterised so as to explain their behaviour. A... 
Tipo: Text 
Palavraschave: Marine current turbine; Performance; Wake; Turbulence; Array; Tidal turbine. 
Ano: 2014 
URL: http://archimer.ifremer.fr/doc/00175/28644/27110.pdf 
 


Maganga, Fabrice; Germain, Gregory; King, Jérémy; Pinon, Grégory; Rivoalen, Elie. 
This paper presents experimental results from tests carried out in the Ifremer free surface circulation flume tank. The objective of this work is to validate the numerical work conducted under a PhD programme for the characterization of flow perturbations induced by marine current turbines. For that purpose, we used a tribladed horizontal axis turbine. The work is dedicated to measure the behaviour of the system and to characterize the wake emitted by the turbine. The efficiency of the turbine is quantified by the measurement of the thrust and the amount of power generated by the rotor for various inflow conditions, while the wake will be characterized by Laser Doppler Velocimetry. Particular attention is paid to the flow characteristic effects (velocity... 
Tipo: Text 

Ano: 2009 
URL: http://archimer.ifremer.fr/doc/00022/13362/10389.pdf 
 


Mycek, Paul; Pinon, Gregory; Germain, Gregory; Rivoalen, Elie. 
The modelling of diffusive terms in particle methods is a delicate matter and several models were proposed in the literature to take such terms into account. The diffusion velocity method (DVM), originally designed for the diffusion of passive scalars, turns diffusive terms into convective ones by expressing them as a divergence involving a socalled diffusion velocity. In this paper, DVM is extended to the diffusion of vectorial quantities in the threedimensional Navier–Stokes equations, in their incompressible, velocity–vorticity formulation. The integration of a large eddy simulation (LES) turbulence model is investigated and a DVM general formulation is proposed. Either with or without LES, a novel expression of the diffusion velocity is derived,... 
Tipo: Text 
Palavraschave: Diffusion velocity method; Particle method; Fourier analysis; Transportdispersion equations; NavierStokes equations. 
Ano: 2016 
URL: https://archimer.ifremer.fr/doc/00250/36128/34772.pdf 
 


Choma Bex, Camille; Pinon, Gregory; Slama, Myriam; Gaston, Benoist; Germain, Gregory; Rivoalen, Elie. 
This paper presents possible techniques for modelling ambient turbulence in the Lagrangian Vortex Method formalism. Due to the fact that regular Synthetic Eddy Method (SEM) already presented in previous studies is not divergence free by definition; improvements were necessary to develop a similar SEM method with such a divergence free property. The recent improvements formulated by R. Poletto give the way to such a possibility. This new Divergence Free Synthetic Eddy Method (DFSEM) is presented here in comparison with the regular SEM. Obtained numerical velocity fields are compared in terms of convergence properties, Power Spectral Density and also Taylor macroscale. Finally, turbine wakes are computed with both the recent Poletto's DFSEM and the regular... 
Tipo: Text 

Ano: 2020 
URL: https://archimer.ifremer.fr/doc/00652/76443/77531.pdf 
 


Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Lothode, Corentin; Pinon, Gregory; Rivoalen, Elie. 
The implantation and deployment of marine current turbine arrays depend on the understanding of their interactions. Based on a priori suggestions about the layout of marine energy converter arrays, we propose to highlight interactions effects between two horizontal axis marine current turbines, in open water. experimental trials were run in IFREMER’s wave and current flume tank in BoulognesurMer (France), on marine current turbine models. Our study focuses on setups were the second turbine is axially aligned, at different distances, in the wake of the first one. Interaction effects are pointed out both in terms of performance and wake characterisation by means of a comparison with results on a single turbine. This study shows that the downstream turbine... 
Tipo: Text 
Palavraschave: Marine energy; Horizontal axis marine current turbine arrays; Experimental trials; Laser Doppler velocimetry; Numerical simulation; Vortex method. 
Ano: 2013 
URL: http://archimer.ifremer.fr/doc/00143/25401/23557.pdf 
 

 


Maganga, Fabrice; Germain, Gregory; Pinon, Grégory; Rivoalen, Elie. 
Numerical results for the wake of a three bladed horizontal axis turbine in a uniform free upstream current are presented. A threedimensional software, taking into account the non stationary evolution of the wake emitted by turbine blades is developed in order to assess the disturbances generated on the seabed and on the free surface. An unsteady Lagrangian method is considered for these simulations using Vortex Method. The vortex ow is discretised with particles carrying vorticity, which are advected in a Lagrangian frame. 
Tipo: Text 

Ano: 2008 
URL: http://archimer.ifremer.fr/doc/00022/13367/10391.pdf 
 


Pinon, Gregory; Mycek, Paul; Germain, Gregory; Rivoalen, Elie. 
This paper presents numerical computations of three bladed horizontal axis marine current turbines in a uniform free upstream current. The unsteady evolution of the turbine wake is taken into account by some threedimensional software, developed to assess the disturbances generated in the sea. An unsteady Lagrangian method is considered for these computations using "Vortex Method": a velocityvorticity numerical implementation of the NavierStokes equations. The vortex flow is discretised with particles carrying vorticity, which are advected in a Lagrangian frame. The present paper aims at presenting results on both power and thrust coefficient (Cp and CT) predictions and wake characterisation, up to ten diameters downstream of the turbine. Moreover, two... 
Tipo: Text 
Palavraschave: Numerical computations; Marine current turbine; Hydrodynamic; Power and thrust coefficients; Wake. 
Ano: 2012 
URL: http://archimer.ifremer.fr/doc/00087/19853/17616.pdf 
 


Maganga, Fabrice; Pinon, Grégory; Germain, Gregory; Rivoalen, Elie. 
This paper presents numerical results for the wake behind a three bladed horizontal axis turbine in a uniform free upstream current. A threedimensional software, initially issuing from Pinon et al. [6], taking into account the non stationary evolution of the wake emitted by turbine blades is developed in order to assess the disturbances generated on the seabed and on the free surface. So an unsteady Lagrangian method is considered for these simulations using Vortex Method. The vortex flow is discretised with particles carrying vorticity, which are advected in a Lagrangian frame. 
Tipo: Text 

Ano: 2008 
URL: http://archimer.ifremer.fr/doc/00023/13429/10436.pdf 
 

 


Germain, Gregory; Maganga, Fabrice; Gaurier, Benoit; Facq, Jeanvalery; Bacchetti, Thomas; Pinon, Grégory; Rivoalen, Elie; Etancelin, Jeanmatthieu. 
This paper presents experimental results of tests carried out in order to investigate the hydrodynamics of marine current turbines and to build an experimental database used to validate the numerical developments conducted to characterize the flow perturbations induced by marine current turbines. For that purpose, we used a tribladed horizontal axis turbine. Particular attention is paid to the flow characteristic effects (velocity gradient, flow orientation, flow turbulence intensity level) on the performance of a 0.70 m diameter turbine. The main interest is to study how the far wake decays downstream, in order to estimate the effect produced in downstream turbines. Analyses are made from Laser Doppler Velocimeter measurements (velocity and turbulence... 
Tipo: Text 

Ano: 2010 
URL: http://archimer.ifremer.fr/doc/00021/13263/10310.pdf 
 
Registros recuperados: 22  


