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| Registros recuperados: 22 | |
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| Maganga, Fabrice; Pinon, Grégory; Germain, Gregory; Rivoalen, Elie. |
| The hydrodynamics of a three bladed horizontal axis turbine is investigated. The performance of a turbine of 0.7 m of diameter and its wake were obtained from experiments and numerical simulations. A six components load cells is used for thrust and hydrodynamic power measurements, and Laser Doppler Velocimetry technics for wake characterisation. A three-dimensional software, taking into account the non stationary evolution of the wake generated by turbine blades is developed. The flow is discretised with particles carrying vorticity, which are advected in a Lagrangian frame. Both numerical and experimental power coefficient Cp and velocity maps were compared. Experiments and numerical data showed a satisfactory agreement in term of the shape of the wake... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00022/13356/10387.pdf |
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| 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 so-called diffusion velocity. In addition to the actual velocity, it is used to compute the particles displacement. On the other hand, the well-known 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 |
Palavras-chave: Particle method; Diffusion; DVM; PSE. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00159/27006/25254.pdf |
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| 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 three-dimensional software, developed to assess the disturbances generated in the sea. An unsteady Lagrangian method is considered for these computations using "Vortex Method": a velocity-vorticity numerical implementation of the Navier-Stokes 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 (C-p and C-T) predictions and wake characterisation, up to ten diameters downstream of the turbine. Moreover, two... |
| Tipo: Text |
Palavras-chave: Numerical computations; Marine current turbine; Hydrodynamic; Power and thrust coefficients; Wake. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19853/17616.pdf |
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| 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 Boulogne-sur-Mer, 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 three-dimensional 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 |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00141/25200/23360.pdf |
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| 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 3-bladed 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 |
Palavras-chave: Marine current turbine; Performance; Wake; Turbulence; Array; Tidal turbine. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28644/27110.pdf |
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| Maganga, Fabrice; Germain, Gregory; Facq, Jean-valery; 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 tri-pales 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 |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00022/13355/10386.pdf |
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| 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 (Boulogne-sur-Mer) flume tank. Those experiments used 3-bladed horizontal axis marine current turbines prototypes, regulated in rotation speed. To complete these experiments, a three-dimensional 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 |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00247/35806/34320.pdf |
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| 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 tri-bladed 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 |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00022/13362/10389.pdf |
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| 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 three-dimensional 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 sea-bed 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 |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00023/13429/10436.pdf |
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| 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 three-dimensional 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 sea-bed 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 |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00022/13367/10391.pdf |
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| 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 Boulogne-sur-Mer (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 |
Palavras-chave: 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 |
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| 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 Boulogne-Sur-Mer (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 |
Palavras-chave: Marine current turbine; Performance; Wake; Turbulence; Experiment; Flume tank. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28647/27171.pdf |
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| 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 so-called diffusion velocity. In this paper, DVM is extended to the diffusion of vectorial quantities in the three-dimensional 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 |
Palavras-chave: Diffusion velocity method; Particle method; Fourier analysis; Transport-dispersion equations; Navier-Stokes equations. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00250/36128/34772.pdf |
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| 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 macro-scale. Finally, turbine wakes are computed with both the recent Poletto's DFSEM and the regular... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76443/77531.pdf |
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| Germain, Gregory; Maganga, Fabrice; Gaurier, Benoit; Facq, Jean-valery; Bacchetti, Thomas; Pinon, Grégory; Rivoalen, Elie; Etancelin, Jean-matthieu. |
| 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 tri-bladed 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 |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00021/13263/10310.pdf |
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| 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 |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00252/36293/34822.pdf |
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| Registros recuperados: 22 | |
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