Two-Dimensional Wind Tunnel and Computational Investigation of a Microtab Modified Airfoil

Baker, Jonathon P.; Standish, Kevin; Dam, C. P. van

doi:10.2514/1.24502

Cited by 71 publications

(52 citation statements)

References 12 publications

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“…The potential of MTs was first investigated by van Dam et al [18]. Baker et al [19] carried out broad study dedicated to the S809 airfoil with MTs. These MTs jets the flow in the boundary layer away from the blade's surface, bringing a recirculation zone behind the tab, as can be observed in Figure 1.The MTs affect the airfoil aerodynamics shifting the point of flow separation and, therefore, providing changes in lift.…”

Section: Introductionmentioning

confidence: 99%

Microtab Design and Implementation on a 5 MW Wind Turbine

et al. 2017

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Microtabs (MT) consist of a small tab placed on the airfoil surface close to the trailing edge and perpendicular to the surface. A study to find the optimal position to improve airfoil aerodynamic performance is presented. Therefore, a parametric study of a MT mounted on the pressure surface of an airfoil has been carried out. The aim of the current study is to find the optimal MT size and location to increase airfoil aerodynamic performance and to investigate its influence on the power output of a 5 MW wind turbine. Firstly, a computational study of a MT mounted on the pressure surface of the airfoil DU91W(2)250 has been carried out and the best case has been found according to the largest lift-to-drag ratio. This airfoil has been selected because it is typically used on wind turbine, such as the 5 MW reference wind turbine of the National Renewable Energy Laboratory (NREL). Second, Blade Element Momentum (BEM) based computations have been performed to investigate the effect of the MT on the wind turbine power output with different wind speed realizations. The results show that, due to the implementation of MTs, a considerable increase in the turbine average power is achieved.

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Section: Introductionmentioning

confidence: 99%

Microtab Design and Implementation on a 5 MW Wind Turbine

et al. 2017

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“…Previous studies [4,5,7,[13][14][15] have shown that microtab and gurney flap have similar behaviours and, for efficiency, that microtab should have a typical height of the order of the boundary-layer thickness of the aerofoil. More precise experiments and simulations, in particular for the S809 and DU-96-W-180 aerofoils demonstrated that microtab height above 2% of the chord length results in a significant increase in drag.…”

Section: Microtab Aerodynamic Response Modellingmentioning

confidence: 99%

“…In comparison to trailing edge flaps, which have been extensively studied for helicopter blades applications, load alleviation using microtabs is a relatively new field of research. Most of earlier research works on microtab were focused on its effectiveness in changing the aerodynamic performance of aerofoils [5][6][7][8]. These works, carrying out numerical and experimental analysis, investigate microtabs steady and transient aerodynamic response and the effect of microtab deployment height and location on the aerodynamic characteristics of the host aerofoils.…”

Section: Introductionmentioning

confidence: 99%

Integrated aeroelastic and control analysis of wind turbine blades equipped with microtabs

Macquart

Maheri

2015

Renewable Energy

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Northumbria University has developed Northumbria Research Link (NRL) to enable users to access the University's research output. Copyright © and moral rights for items on NRL are retained by the individual author(s) and/or other copyright owners. Single copies of full items can be reproduced, displayed or performed, and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided the authors, title and full bibliographic details are given, as well as a hyperlink and/or URL to the original metadata page. The content must not be changed in any way. Full items must not be sold commercially in any format or medium without formal permission of the copyright holder. The full policy is available online: http://nrl.northumbria.ac.uk/policies.html This document may differ from the final, published version of the research and has been made available online in accordance with publisher policies. To read and/or cite from the published version of the research, please visit the publisher's website (a subscription may be required.)Published in Renewable Energy 75 (2015) 102-114 Terence Macquart & Alireza Maheri 1 Integrated Aeroelastic and Control Analysis of Wind Turbine Blades Equipped with MicrotabsTerence Macquart and Alireza Maheri Faculty of Engineering and Environment, Northumbria University, UK AbstractThis paper presents the results of an investigation into the performance of different controllers in active load control of wind turbine blades equipped with microtabs. A bang-bang (BB) controller, a linear quadratic regulator (LQR) a proportional integral derivative (PID) and a sliding mode controller (SMC) are synthesised for load alleviation. The performance of the synthesised controllers in load alleviation is evaluated by employing WTAC (Wind Turbine Aeroelastic and Control), a wind turbine simulator incorporating an unsteady aerodynamic module, a structural analysis module and a control module. The variable-speed pitch-controlled NREL-5MW is adopted as the case study. Using frequency domain analysis it is shown that for the studied case all controllers have more or less the same performance at rejecting the first rotational frequency loads. It is also shown that all controllers are more effective at rejecting loads with lower frequencies. BB and PID controllers, although capable of rejecting low frequency loads, may cause amplification of loads with higher frequencies. Investigating the performance of four controllers at different wind speeds for the studied wind turbine, it is observed that the effectiveness of BB and PID controllers reduces with wind speed but on the other hand SMC and LQR perform better at higher wind speeds. Introducing a new parameter, life index, the performance of different controllers in terms of the actuation wear is investigated. It is shown that LQR cause less actuation wear compared to SMC, while having comparable performance in load alleviation.

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“…This paper focuses on microtabs [1,[5][6][7][8]. The microtab is based on the same concept as the Gurney flap, which changes the aerodynamic characteristics by altering the blade's airfoil section geometry in the trailing edge region [9].…”

Section: Introductionmentioning

confidence: 99%

An Innovative Design of a Microtab Deployment Mechanism for Active Aerodynamic Load Control

et al. 2015

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This study presents an innovative design of a microtab system for aerodynamic load control on horizontal-axis wind-turbine rotors. Microtabs are small devices located near the trailing edge of the rotor blades and enable a rapid increase or decrease of the lift force through deployment of the tabs on the pressure or suction side of the airfoil, respectively. The new system has been designed to replace an earlier linearly-actuated microtab mechanism whose performance was limited by space restrictions and stiction. The newly-designed microtab system is based on a four-bar linkage that overcomes the two drawbacks. Its improved kinematics allows for the tab height to increase from 1.0% to 1.7% of the airfoil chord when fully deployed, thereby making it more effective in terms of aerodynamic load control. Furthermore, the modified four-bar link mechanism provides a more robust and reliable mechanical structure.

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Two-Dimensional Wind Tunnel and Computational Investigation of a Microtab Modified Airfoil

Cited by 71 publications

References 12 publications

Microtab Design and Implementation on a 5 MW Wind Turbine

Microtab Design and Implementation on a 5 MW Wind Turbine

Integrated aeroelastic and control analysis of wind turbine blades equipped with microtabs

An Innovative Design of a Microtab Deployment Mechanism for Active Aerodynamic Load Control

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