8.05 – Air Turbines
01 Jan 2012-Vol. 8, pp 111-149
TL;DR: In this paper, the authors presented the aerodynamic theory of axial-flow turbines and applied it to the Wells turbine and the impulse turbine, including their variants, in order to analyze their integration into the OWC wave energy converter.
Abstract: Air turbines are used to equip oscillating water column wave energy converters. In almost every case, self-rectifying turbines have been adopted which do not require non-return valves to rectify the reciprocating air flow induced by the water column oscillations. The most frequently used or proposed self-rectifying air turbines are the Wells turbine and the impulse turbine, both of axial-flow type. The fundamentals of the aerodynamic theory of axial-flow turbines are presented and then applied to the Wells turbine and the impulse turbine, including their variants. Information is given on methods of, and results from, air turbine model testing, as well as on self-rectifying air turbines that equipped or equip prototypes tested in the sea. The final part of the chapter is devoted to the analysis of turbine integration into OWC wave energy converter.
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TL;DR: In this article, the authors provide an updated and a comprehensive account of the state of the art research on Wells turbine and draw a roadmap for the contemporary challenges which may hinder future reliance on such systems in the renewable energy sector.
Abstract: In the past twenty years, the use of wave energy systems has significantly increased, generally depending on the oscillating water column (OWC) concept. Wells turbine is one of the most efficient OWC technologies. This article provides an updated and a comprehensive account of the state of the art research on Wells turbine. Hence, it draws a roadmap for the contemporary challenges which may hinder future reliance on such systems in the renewable energy sector. In particular, the article is concerned with the research directions and methodologies which aim at enhancing the performance and efficiency of Wells turbine. The article also provides a thorough discussion of the use of computational fluid dynamics (CFD) for performance modeling and design optimization of Wells turbine. It is found that a numerical model using the CFD code can be employed successfully to calculate the performance characteristics of W-T as well as other experimental and analytical methods. The increase of research papers about CFD, especially in the last five years, indicates that there is a trend that considerably depends on the CFD method.
84 citations
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TL;DR: In this article, the authors present a new systematic methodology for optimum design of wave energy converters, which is applied to design two self-powered sensor buoys for long term monitoring based on the oscillating water column principle.
69 citations
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TL;DR: In this article, a power take-off control of an OWC (oscillating-water-column) spar-buoy wave energy converter was investigated. And the experimental results allowed the dynamic behaviour of the PTO to be characterized and provided validation of the proposed control algorithms that ensure operation within safe limits.
64 citations
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TL;DR: In this article, a numerical work relying on design optimization is reported to show the dependency of power extraction capability to the operating range of the turbine, and a surrogate approximation model was constructed to find an optimal design.
57 citations
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TL;DR: In this article, a detailed analysis of the dynamics and control of air turbines and electrical generators in oscillating-water-columns (OWCs) is presented to explain the performance of an OWC device based on the physical behaviour of each system component.
Abstract: The paper presents a detailed analysis of the dynamics and control of air turbines and electrical generators in oscillating-water-columns (OWCs). The aim is to explain the performance of an OWC device based on the physical behaviour of each system component. The Mutriku wave power plant was chosen as the test case. The power plant is a breakwater located in the Bay of Biscay, in Basque Country, Spain. The contributions of the work are: i) development of a hydrodynamic model of the power plant in the frequency domain; ii) implementation of a non-linear time-domain wave-to-wire model; iii) real-valued implementation of the Prony method for the computation of the wave-radiation force; iv) a detailed generator model based on experimental data to assess the influence of the generator efficiency on the power take-off performance; v) a critical performance comparison of the Wells and biradial turbines; vi) a sensitivity analysis of the control parameters of the turbine/generator set; and vii) an explanation of the comparative performance of both turbines based on statistical data. The turbine performance curves were taken from developers’ published experimental data. The results were obtained with a simplified model of the wave climate off the Mutriku test site comprising 14 sea states.
41 citations
References
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01 Jan 1959
TL;DR: Chang et al. as discussed by the authors proposed a new geometric analysis procedure for wing sections based on the normal mode analysis for continuous functions, which can be used to calculate the section length.
Abstract: The thin airfoil theory for calculation of section ... http://charles-oneill.com/projects/iaf.pdf Thin Airfoil Theory Charles R. O’Neill ... The objective is to review the thin airfoil theory and to apply the theory to three wing sections. THEORY OF WINGS AND WIND TUNNEL TESTING OF A NACA 2415 AIRFOIL http://www.ewp.rpi.edu/hartford/~ernesto/F2011/EP/MaterialsforStudents/Ferrari/Ghods2001.PDF 2.0 STRUCTURE AND THEORY OF WINGS Wing is an aerodynamic structure that generates lift when comes into contact with moving air molecules i.e. wind. tbausyd.wikispaces.com http://tbausyd.wikispaces.com/file/view/aerodynamics_report1.3.doc Abbot & von Doenhoff, 1959, 'Theory of Wing Sections – including a summary of airfoil data', Dover Edition, Dover Publications, New York. Geometric Analysis of Wing Sections RITA | National ... http://ntl.bts.gov/lib/1000/1200/1265/950049_chang.pdf GEOMETRIC ANALYSIS OF WING SECTIONS I-Chung Chang, Francisco J. Torres, and Chee Tung? Ames Research Center SUMMARY This paper describes a new geometric analysis ... Geometric Analysis of Wing Sections NASA http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19950018209_1995118209.pdf This paper describes a new geometric analysis procedure for wing sections. This procedure is based on the normal mode analysis for continuous functions. 4. Incompressible Potential Flow Virginia Tech http://www.dept.aoe.vt.edu/~mason/Mason_f/C4WHMPanels.doc
1,956 citations
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01 Nov 1966
TL;DR: The Fluid Mechanics and Thermodynamics of Turbomachines (FLMTH) as discussed by the authors is a classic text in the field of turbomachines, which has been used as a core text in both undergraduate and graduate level courses.
Abstract: Turbomachinery is a challenging and diverse field, with applications for professionals and students in many subsets of the mechanical engineering discipline, including fluid mechanics, combustion and heat transfer, dynamics and vibrations, as well as structural mechanics and materials engineering. Originally published more than 40 years ago, Fluid Mechanics and Thermodynamics of Turbomachinery is the leading turbomachinery textbook. Used as a core text in senior undergraduate and graduate level courses this book will also appeal to professional engineers in the aerospace, global power, oil & gas and other industries who are involved in the design and operation of turbomachines. For this new edition, author S. Larry Dixon is joined by Cesare Hall from the University of Cambridge, whose diverse background of teaching, research and work experience in the area of turbomachines is well suited to the task of reorganizing and updating this classic text. NEW AND KEY FEATURES * Provides the most comprehensive coverage of the fundamentals of turbomachinery of any text in the field* Content has been reorganized to more closely match how instructors currently teach the course* Coverage of fluid mechanics and thermodynamics, the basis on which good turbomachine performance depends, has been moved to the front of the book* Includes new design studies of several turbomachines, applying the theories developed in the book* Figures have been updated, along with new photos added, to better illustrate the topics presented* Includes new examples and additional end-of-chapter exercises
831 citations
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01 Dec 1995
TL;DR: In this paper, the dynamique des : fluides, transfert de chaleur, turbomachines, aerodynamique, thermodynamique Reference Record created on 2005-11-18, modified on 2016-08-08
Abstract: Keywords: dynamique des : fluides ; transfert de chaleur ; turbomachines ; aerodynamique ; thermodynamique Reference Record created on 2005-11-18, modified on 2016-08-08
528 citations