Documents disponibles écrits par cet auteur

Computational fluid dynamics analysis of a hydrokinetic turbine based on oscillating hydrofoils / Thomas Kinsey in Transactions of the ASME . Journal of fluids engineering, Vol. 134 N° 2 (Fevrier 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 2 (Fevrier 2012) . - 16 p. Titre : Computational fluid dynamics analysis of a hydrokinetic turbine based on oscillating hydrofoils Type de document : texte imprimé Auteurs : Thomas Kinsey, Auteur ; Guy Dumas, Auteur Année de publication : 2012 Article en page(s) : 16 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Hydrokinetic  turbine  Oscillating  hydrofoils  URANS  numerical  simulations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The performance of a new concept of hydrokinetic turbine using oscillating hydrofoils to extract energy from water currents (tidal or gravitational) is investigated using URANS numerical simulations. The numerical predictions are compared with experimental data from a 2 kW prototype, composed of two rectangular oscillating hydrofoils of aspect ratio 7 in a tandem spatial configuration. 3D computational fluid dynamics (CFD) predictions are found to compare favorably with experimental data especially for the case of a single-hydrofoil turbine. The validity of approximating the actual arc-circle trajectory of each hydrofoil by an idealized vertical plunging motion is also addressed by numerical simulations. Furthermore, a sensitivity study of the turbine's performance in relation to fluctuating operating conditions is performed by feeding the simulations with the actual time-varying experimentally recorded conditions. It is found that cycle-averaged values, as the power-extraction efficiency, are little sensitive to perturbations in the foil kinematics and upstream velocity. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000002 [...] [article] Computational fluid dynamics analysis of a hydrokinetic turbine based on oscillating hydrofoils [texte imprimé] / Thomas Kinsey, Auteur ; Guy Dumas, Auteur . - 2012 . - 16 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 2 (Fevrier 2012) . - 16 p. Mots-clés : Hydrokinetic  turbine  Oscillating  hydrofoils  URANS  numerical  simulations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The performance of a new concept of hydrokinetic turbine using oscillating hydrofoils to extract energy from water currents (tidal or gravitational) is investigated using URANS numerical simulations. The numerical predictions are compared with experimental data from a 2 kW prototype, composed of two rectangular oscillating hydrofoils of aspect ratio 7 in a tandem spatial configuration. 3D computational fluid dynamics (CFD) predictions are found to compare favorably with experimental data especially for the case of a single-hydrofoil turbine. The validity of approximating the actual arc-circle trajectory of each hydrofoil by an idealized vertical plunging motion is also addressed by numerical simulations. Furthermore, a sensitivity study of the turbine's performance in relation to fluctuating operating conditions is performed by feeding the simulations with the actual time-varying experimentally recorded conditions. It is found that cycle-averaged values, as the power-extraction efficiency, are little sensitive to perturbations in the foil kinematics and upstream velocity. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000002 [...]

Optimal tandem configuration for oscillating-foils hydrokinetic turbine / Thomas Kinsey in Transactions of the ASME . Journal of fluids engineering, Vol. 134 N° 3 (Mars 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 3 (Mars 2012) . - 11 p. Titre : Optimal tandem configuration for oscillating-foils hydrokinetic turbine Type de document : texte imprimé Auteurs : Thomas Kinsey, Auteur ; Guy Dumas, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Oscillating  foils  Optimal  spatial  configuration  Hydrokinetic  turbine  Power  extraction  efficiency Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A numerical investigation based on 2D URANS simulations is performed in order to seek an optimal spatial configuration for two oscillating foils within a hydrokinetic turbine. The objective of the study is to maximize the power extraction efficiency of the turbine. Tandem spatial configurations are considered because in such arrangement both hydrofoils are sharing the same flow window, which allows the turbine to reach higher efficiencies. The relative positioning of the downstream foil oscillating in the wake shed by the upstream hydrofoil is seen to be critical. Indeed, favorable interactions between the downstream foil and the wake vortices may lead to unexpectedly high power-extraction efficiencies (up to 64%), while unfavorable interactions may cause the downstream foil to contribute negatively to the total power extracted. A global phase shift parameter is introduced to characterize the tandem configuration. This parameter combines the inter-foil spacing and motion phase-shift into a single term. It is found useful to predict additional favorable configurations based on known results for cases with similar upstream-foil wake behavior. A comparison with experimental data is provided. Numerical predictions are seen to overpredict the power extraction performance in some cases. This is likely due to the broken 2D coherence of vortices in the 3D reality which affects the vortex-induced velocities and the subsequent foil-wake interactions. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000003 [...] [article] Optimal tandem configuration for oscillating-foils hydrokinetic turbine [texte imprimé] / Thomas Kinsey, Auteur ; Guy Dumas, Auteur . - 2012 . - 11 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 3 (Mars 2012) . - 11 p. Mots-clés : Oscillating  foils  Optimal  spatial  configuration  Hydrokinetic  turbine  Power  extraction  efficiency Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A numerical investigation based on 2D URANS simulations is performed in order to seek an optimal spatial configuration for two oscillating foils within a hydrokinetic turbine. The objective of the study is to maximize the power extraction efficiency of the turbine. Tandem spatial configurations are considered because in such arrangement both hydrofoils are sharing the same flow window, which allows the turbine to reach higher efficiencies. The relative positioning of the downstream foil oscillating in the wake shed by the upstream hydrofoil is seen to be critical. Indeed, favorable interactions between the downstream foil and the wake vortices may lead to unexpectedly high power-extraction efficiencies (up to 64%), while unfavorable interactions may cause the downstream foil to contribute negatively to the total power extracted. A global phase shift parameter is introduced to characterize the tandem configuration. This parameter combines the inter-foil spacing and motion phase-shift into a single term. It is found useful to predict additional favorable configurations based on known results for cases with similar upstream-foil wake behavior. A comparison with experimental data is provided. Numerical predictions are seen to overpredict the power extraction performance in some cases. This is likely due to the broken 2D coherence of vortices in the 3D reality which affects the vortex-induced velocities and the subsequent foil-wake interactions. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000003 [...]

Three-dimensional effects on an oscillating-foil hydrokinetic turbine / Thomas Kinsey in Transactions of the ASME . Journal of fluids engineering, Vol. 134 N° 7 (Juillet 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 7 (Juillet 2012) . - 11 p. Titre : Three-dimensional effects on an oscillating-foil hydrokinetic turbine Type de document : texte imprimé Auteurs : Thomas Kinsey, Auteur ; Guy Dumas, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : three-dimensional  hydrodynamic  losses;  foil  oscillating  sinusoidally;  unsteady  Reynolds-Averaged-Navier-Stokes  (URANS)  solver Résumé : Three-dimensional hydrodynamic losses are assessed in this investigation for a foil oscillating sinusoidally in a combined heave and pitch motion with large amplitudes. Simulations are performed using a unsteady Reynolds-Averaged-Navier-Stokes (URANS) solver on an oscillating foil in a power-extraction mode; thus acting as a hydrokinetic turbine at high Reynolds number. Foils of various aspect ratios (span to chord length ratio) are considered, both with and without endplates for one representative operation point. Hydrodynamic forces and extracted power are compared with results from the equivalent two-dimensional (2D) computations. It is found that the relative drop of performance (cycle-averaged power extracted) due to 3D hydrodynamic losses can be limited to 10% of the 2D prediction when endplates are used on a foil of aspect ratio greater than ten. The practical consideration of an oscillating-foil hydrokinetic turbine operating in an imperfectly-aligned upstream water flow is also addressed with simulations considering an upstream flow at a yaw angle up to 30° with respect to the foil chord line. Effects on performance are found to be proportional to the projected kinetic energy flux. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000007 [...] [article] Three-dimensional effects on an oscillating-foil hydrokinetic turbine [texte imprimé] / Thomas Kinsey, Auteur ; Guy Dumas, Auteur . - 2012 . - 11 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 7 (Juillet 2012) . - 11 p. Mots-clés : three-dimensional  hydrodynamic  losses;  foil  oscillating  sinusoidally;  unsteady  Reynolds-Averaged-Navier-Stokes  (URANS)  solver Résumé : Three-dimensional hydrodynamic losses are assessed in this investigation for a foil oscillating sinusoidally in a combined heave and pitch motion with large amplitudes. Simulations are performed using a unsteady Reynolds-Averaged-Navier-Stokes (URANS) solver on an oscillating foil in a power-extraction mode; thus acting as a hydrokinetic turbine at high Reynolds number. Foils of various aspect ratios (span to chord length ratio) are considered, both with and without endplates for one representative operation point. Hydrodynamic forces and extracted power are compared with results from the equivalent two-dimensional (2D) computations. It is found that the relative drop of performance (cycle-averaged power extracted) due to 3D hydrodynamic losses can be limited to 10% of the 2D prediction when endplates are used on a foil of aspect ratio greater than ten. The practical consideration of an oscillating-foil hydrokinetic turbine operating in an imperfectly-aligned upstream water flow is also addressed with simulations considering an upstream flow at a yaw angle up to 30° with respect to the foil chord line. Effects on performance are found to be proportional to the projected kinetic energy flux. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000007 [...]