The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Maurizio Collu - One of the best experts on this subject based on the ideXlab platform.
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offshore floating vertical axis wind turbines dynamics Modelling state of the art part i Aerodynamics
Renewable & Sustainable Energy Reviews, 2014Co-Authors: Michael Borg, Andrew Shires, Maurizio ColluAbstract:The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative concepts in this context. Vertical axis wind turbines (VAWTs) are one promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating VAWTs to assess their technical feasibility. A comprehensive review detailing the areas of engineering expertise utilised in developing an understanding of the coupled dynamics of floating VAWTs has been developed through a series of articles. This first article details the Aerodynamic Modelling of VAWTs, providing a review of available models, discussing their applicability to floating VAWTs and current implementations by researchers in this field. A concise comparison between conventional horizontal axis wind turbines and VAWTs is also presented, outlining the advantages and disadvantages of these technologies for the floating wind industry. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of Modelling approaches may be found.
David J N Limebee - One of the best experts on this subject based on the ideXlab platform.
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aeroelastic control of long span suspension bridges with controllable winglets
Structural Control & Health Monitoring, 2016Co-Authors: K N Akis, Matteo Massaro, M S Williams, David J N LimebeeAbstract:Summary The structural-Aerodynamic Modelling and dynamic stabilization of a three-dimensional suspension bridge model is considered. Our emphasis is on investigating the effectiveness of leading and trailing edge flaps in suppressing aeroelastic instabilities. The East Great Belt Bridge is chosen as a design example, and its aeroelastic limits are computed using both thin aerofoil theory and flutter derivatives. The problem is cast in an efficient reduced size finite element formulation with Aerodynamic forces expressed in the Laplace domain by use of a high-fidelity rational function approximation. Circulatory Aerodynamic forces are modelled using a feedback loop for every element, and the problem is expressed in a form suitable for implementation of modern control techniques. The structure's full multimodal response is considered, and numerical predictions show very good agreement against experimental data from the literature. In order to account for Modelling errors and uncertainties while designing the controller, elements from robust control theory are invoked. The stability and robustness of the bridge when fitted with flaps controlled by optimal and suboptimal H∞ controllers are discussed for varying lengths of control surfaces along the suspended span as the optimum configuration for Aerodynamic performance is investigated. Copyright © 2016 John Wiley & Sons, Ltd.
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aeroelastic Modelling of long span suspension bridges
IFAC Proceedings Volumes, 2011Co-Authors: Michael J R Graham, David J N Limebee, Xiaowei ZhaoAbstract:Abstract The 2D Aerodynamic Modelling of long-span suspension bridges is considered. We use thin airfoil theory from the aircraft industry and a sectional bridge model with an integrated controllable trailing-edge flap. The relatively less well known Aerodynamic properties of leading-edge flap will be studied in detail. The optimal approximation of the classical Theodorsen circulation function will be studied as part of the bridge sectional model building exercise, which can therefore be re-casted in a form suitable for control systems analysis and design. The critical wind speeds for flutter and torsional divergence are predicted precisely. Static winglets are shown to be relatively ineffective to mitigate torsional divergence.
Michael Borg - One of the best experts on this subject based on the ideXlab platform.
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offshore floating vertical axis wind turbines dynamics Modelling state of the art part i Aerodynamics
Renewable & Sustainable Energy Reviews, 2014Co-Authors: Michael Borg, Andrew Shires, Maurizio ColluAbstract:The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative concepts in this context. Vertical axis wind turbines (VAWTs) are one promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating VAWTs to assess their technical feasibility. A comprehensive review detailing the areas of engineering expertise utilised in developing an understanding of the coupled dynamics of floating VAWTs has been developed through a series of articles. This first article details the Aerodynamic Modelling of VAWTs, providing a review of available models, discussing their applicability to floating VAWTs and current implementations by researchers in this field. A concise comparison between conventional horizontal axis wind turbines and VAWTs is also presented, outlining the advantages and disadvantages of these technologies for the floating wind industry. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of Modelling approaches may be found.
Kevin Knowles - One of the best experts on this subject based on the ideXlab platform.
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Aerodynamic Modelling of insect-like flapping flight for micro air vehicles
Progress in Aerospace Sciences, 2006Co-Authors: S A Ansari, Rafał Żbikowski, Kevin KnowlesAbstract:Abstract Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for a micro air vehicle capable of indoor flight. The development of such a vehicle requires a careful wing Aerodynamic design. This is particularly true since the flapping wings will be responsible for lift, propulsion and manoeuvres, all at the same time. It sets the requirement for an Aerodynamic tool that will enable study of the parametric design space and converge on one (or more) preferred configurations. In this respect, Aerodynamic Modelling approaches are the most attractive, principally due to their ability to iterate rapidly through various design configurations. In this article, we review the main approaches found in the literature, categorising them into steady-state, quasi-steady, semi-empirical and fully unsteady methods. The unsteady Aerodynamic model of Ansari et al. seems to be the most satisfactory to date and is considered in some detail. Finally, avenues for further research in this field are suggested.
Andrew Shires - One of the best experts on this subject based on the ideXlab platform.
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offshore floating vertical axis wind turbines dynamics Modelling state of the art part i Aerodynamics
Renewable & Sustainable Energy Reviews, 2014Co-Authors: Michael Borg, Andrew Shires, Maurizio ColluAbstract:The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative concepts in this context. Vertical axis wind turbines (VAWTs) are one promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating VAWTs to assess their technical feasibility. A comprehensive review detailing the areas of engineering expertise utilised in developing an understanding of the coupled dynamics of floating VAWTs has been developed through a series of articles. This first article details the Aerodynamic Modelling of VAWTs, providing a review of available models, discussing their applicability to floating VAWTs and current implementations by researchers in this field. A concise comparison between conventional horizontal axis wind turbines and VAWTs is also presented, outlining the advantages and disadvantages of these technologies for the floating wind industry. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of Modelling approaches may be found.