Investigation of aerodynamic braking devices for wind turbine applications

Griffin, Dayton A.

doi:10.2172/464145

Cited by 5 publications

(3 citation statements)

References 3 publications

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“…This family was designed to have performance characteristics similar to the previous family. The greater tip-region thickness helps accommodate overspeed-control mechanisms for stall-regulated rotors at the expense of a slightly higher drag [36,37]. Though these mechanisms are not used in modern turbines and were thus not included in this case study, the increased thickness is structurally beneficial.…”

Section: Airfoil Familiesmentioning

confidence: 99%

On the Use of Modern Engineering Codes for Designing a Small Wind Turbine: An Annotated Case Study

et al. 2021

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While most wind energy comes from large utility-scale machines, small wind turbines (SWTs) can still play a role in off-grid installations or in the context of distributed production and smart energy systems. Over the years, these small machines have not received the same level of aerodynamic refinement of their larger counterparts, resulting in a notably lower efficiency and, therefore, a higher cost per installed kilowatt. In an effort to reduce this gap during the design of a new SWT, the scope of the study was twofold. First, it aimed to show how to combine and best exploit the modern engineering methods and codes available in order to provide the scientific and industrial community with an annotated procedure for a full preliminary design process. Secondly, special focus was put on the regulation methods, which are often some of the critical points of a real design. A dedicated sensitivity analysis for a proper setting is provided, both for the pitch-to-feather and the stall regulation methods. In particular, it is shown that stall regulation (which is usually preferred in SWTs) may be a cost-effective and simple solution, but it can require significant aerodynamic compromises and results in a lower annual energy output in respect to a turbine making use of modern stall-regulation strategies. Results of the selected case study showed how an increase in annual energy production (AEP) of over 12% can be achieved by a proper aerodynamic optimization coupled with pitch-to-feather regulation with respect to a conventional approach.

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Section: Airfoil Familiesmentioning

confidence: 99%

On the Use of Modern Engineering Codes for Designing a Small Wind Turbine: An Annotated Case Study

et al. 2021

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“…In an earlier work by Griffin [4], it is attempted a selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated A WT -26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind turbines, Inc.…”

Section: Introductionmentioning

confidence: 99%

“…When wind velocity is high, the other aerodynamic braking systems bring the machine to a halt which affects the power production, but this recommended braking system keeps the wind turbine speed within the rated revolution per minute. The advantages of this system are that there are no mechanical linkages, no moving parts, and maintenance free.In an earlier work by Griffin[4], it is attempted a selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated A WT -26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind turbines, Inc.…”

mentioning

confidence: 99%

Wind Turbine Aerodynamic Braking System Analysis Using Chord Wise Spacing

Kumar

Parammasivam

2015

AMM

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Wind energy is one of the most significant renewable energy sources in the world. It is the only promising renewable energy resource that only can satisfy the nation’s energy requirements over the growing demand for electricity. Wind turbines have been installed all over the wind potential areas to generate electricity. The wind turbines are designed to operate at a rated wind velocity. When the wind turbines are exposed to extreme wind velocities such as storm or hurricane, the wind turbine rotates at a higher speed that affects the structural stability of the entire system and may topple the system. Mechanical braking systems and Aerodynamic braking systems have been currently used to control the over speeding of the wind turbine at extreme wind velocity. As a novel approach, it is attempted to control the over speeding of the wind turbine by aerodynamic braking system by providing the chord wise spacing (opening). The turbine blade with chord wise spacing alters the pressure distribution over the turbine blade that brings down the rotational speed of the wind turbine within the allowable limit. In this approach, the over speeding of the wind turbine blades are effectively controlled without affecting the power production. In this paper the different parameters of the chord wise spacing such as position of the spacing, shape of the spacing, width of the spacing and impact on power generation are analyzed and the spacing parameters are experimentally optimized.

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