• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.344-350
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• 2013

The purpose of this study is to examine the structural stability of a low speed 200 W class gyromill type vertical axis wind turbine system. For the analysis, a commercial code is adopted. The pressure distribution on the rotor blade surface is examined in detail. In order to perform unidirectional FSI(Fluid-Structure Interaction) analysis, the pressure resulted from CFD analysis has been mapped on the surface of wind turbine as load condition. The rotational speed and gravitational force of wind turbine are also considered. The results of FSI analysis show that the wind turbine reveals an enough structural margin. The maximum structural displacement occurs at trailing edge of blade and the maximum stress occurs at the strut.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.796_797
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• 2009

1kW급 저소음 수직형 풍력발전기용 동기발전기 설계에 대해 설명한다. 낮은 풍량에 유리한 수직형 블레이드 특성에 맞춰 발전기는 코깅 토크가 낮아야 하며, 고효율화를 위해 다극형 설계가 유리하다. 현제 국내 수직형 풍력에 적합한 발전기가 대부분이며 수직형 풍력발전기에 적합한 낮은 코깅 토크의 발전기는 일반화 되어있지 않다. 본 논문에서는 동기발전기 최적 설계를 통해 코깅토크를 최소화 시켰고, 다극형 형태를 통해 낮은 풍량에서 고효율 출력을 만들어낼 수 있도록 200rpm에서 역기전력 96V, 1kw의 정격출력을 가지도록 설계 하였다. 수직축형태의 블레이드에 구조에 맞춰 축계통형 발전기 구조를 가지고 있고, 유한요소해석법을 이용 회전자, 고정자, 권선법, 영구자석 등의 구조를 최적화 시켰다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.118-125
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• 2019

In this study, the vibration characteristics and the resonance phenomena of a wind-solar hybrid light pole structure are compared with respect to the wind turbine type through the dynamic response measurement. Two different turbines are considered including 2-bladed and 3-bladed vertical axis wind turbine rotors. The resonance phenomenon that can occur in hybrid light pole structure is analyzed by comparing the dynamic characteristics of the structure and the excitation force under operational conditions. Displacement responses are also estimated using the acceleration measurement data by use of recently proposed method, and it is observed that the amplitude of dynamic displacement responses are in the range of 4-6 cm under the resonance in the case of 2-bladed turbine and those are limited under 2 mm in the case of 3-bladed turbine because there is no resonance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.3
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• pp.177-186
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• 2019

Wind power tower has been used to augment the performance of VAWT (Vertical Axis Wind Turbine). However, inappropriately designed wind power tower could reduce the performance of VAWT. Hence, an optimization study was conducted on a wind power tower. Six design variables were selected, such as the outer radius and the inner radius of the guide wall, the adoption of the splitter, the inner radius of the splitter, the number of the guide wall and the circumferential angle. For the objective function, the periodic averaged torque obtained at the VAWT was selected. In the optimization, Design of Experiment (DOE), Genetic Algorithm (GA), and Artificial Neural Network (ANN) have been applied in order to avoid a localized optimized result. The ANN has been continuously improved after finishing the optimization process at each generation. The performance of the VAWT was improved more than twice when it operated within the optimized wind power tower compared to that obtained at a standalone.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3347-3352
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• 2007

This paper describes a research for the performance improvement of the straight-bladed vertical axis wind turbine. To improve the performance of VAWT, the individual blade pitch control method is adopted. For the wind turbine, CFD analysis is carried out by changing blade pitch angle according to the change of wind speed and wind direction. By this method, capacity and power efficiency of VAWT are obtained according to the wind speed and rotating of rotor, and could predict the overall performance of VAWT. It was manufactured to verify performance of the experimental system that consists of rotor including four blades and base. Furthermore, torque sensor and power generator were installed. Also, active controller which can change the pitch angle of the individual blade according to the wind speed and direction was used.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.107-113
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• 2017

The dynamic characteristics including natural frequencies and excitation frequencies are evaluated for a small 10 kW vertical axis wind turbine. Acceleration responses were measured at 12 distributed locations for impact vibration tests, ambient vibration tests during non-operational and operational conditions, and braking tests during operational condition. The natural frequencies for the lowest 2 bending modes and the first torsional mode were estimated and also the excitation frequencies, i.e. 1P, 2P, 4P, were also estimated according to the rotational speed using the responses under operational conditions (i.e. power generation condition).

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.147-154
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• 2010

The world is gradually running short of fossil fuel. Currently, the role of wind turbine is attracting great attention from all over the world. The objective of this study is to investigate blades of Vertical-axial wind turbine (VAWT) for optimum design using the CFD from the aerodynamics point of view. Because one of the performance of wind turbine depends on shape of blades, the study of comparing one gyro mill type blade and a modified one was carried out. Using the results of computation, we calculated and compared RPM for both models at same wind velocity. And we calculated angular acceleration and moment of inertia to find torque in every time-step. And the pressure contour and velocity profile around the blade were analyzed Also, this study is performed to calculate the wake effect.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.8
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• pp.877-884
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• 2006

The objective of this study is to investigate the aerodynamic characteristics of a vertical axis wind turbine blade as the basic study of a design of a vertical axis wind turbine. The lift and drag coefficients of the various shape of the vortical axis wind turbine blades are analyzed and compared using the CFD code Fluent. To validate the numerical analysis, the predicted results of the Fluent are compared with those of the Xfoil code and the experimental results. We conclude that the program Fluent can be used to predict the aerodynamics of the wind turbine blade. By comparing the predicted results of the aerodynamic characteristics of the different shape of the blades, an appropriate shape of the blade is suggested to design the vortical axis wind turbine blade.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.602-606
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• 2011

In this study, operational vibration experiment and analysis have been conducted for the 4-blade small vertical-axis wind turbine (VAWT) including the effect of tower elastic behavior. Computational structural dynamics analysis method is applied to obtain Campbell diagram for the VAWT with elastic tower. An open type wind-tunnel is used to change and keep the wind velocity during the ground test. Equivalent reduced elastic tower is supported to the VAWT so that the elastic stiffness effect of the tower can be reflected to the present vibration experiment. Various excitation sources with aerodynamic forces are considered and the dominant operating vibration phenomena are physically investigated in detail.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.493-493
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• 2009

Recently, small vertical axis wind turbine attracts attention because of its clean, renewable and abundant energy resources to develop. Therefore, a cross-flow type wind turbine is proposed for small wind turbine development in this study because the turbine has relatively simple structure and high possibility of applying to small wind turbine. The purpose of this study is to investigate the effect of the turbine‘s structural configuration on the performance and internal flow characteristics of the cross-flow turbine model using CFD analysis. The results show that guide nozzle should be adopted to improve the performance of the turbine. Optimization of the nozzle shape will be key-importance for the high performance of the turbine.