• 한국정밀공학회지
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• 제30권9호
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• pp.977-982
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• 2013

Blades of wind energy plants are exposed to external shocks or internal cracks during operation. Furthermore, the blade surfaces can be contaminated by substances such as dust, blood of birds, salt or insects which can decrease the electricity generation efficiency significantly. For this reason, many blade cleaning companies started to appear and a variety of methods for cleaning were suggested. Despite these diverse methods, there has been no study to investigate how effectively to clean the substances in quantitative manner. In this paper, the cleaning efficiency of two rotor blade cleaning methods, brush and water-jet, is examined through experiments by changing operating parameters. Then, the optimal operating conditions for both methods are derived.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.243-248
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• 2011

The 3-dimensional flow field has been investigated by numerical analysis in a 2.5MW wind turbine blade. Complicated and separated flaw phenomena in the wind turbine blade were captured by the Reynolds-averaged Navier-Stokes(RANS) steady flaw simulation using general-purpose code, CFX and the mechanism of vortex structure behavior is elucidated. The vortical flow field in a wind turbine rotor is dominated by the tip vortex and hub separation vortex. The tip vortex starts to be formed near the blade tip leading edge. As the tip vortex develops in the tangential direction, interacting with boundary layer from the blade tip trailing edge. The hub separation vortex is generated near the blade hub leading edge and develops nearly in the span-wise direction. Furthermore, 3-dimensional blade tip shape has been designed for increasing shrift power and reducing thrust force on the wind turbine blade. It is expected that the behavior of the tip vortex and hub separation vortex plays a major role in aerodynamic and aeroacoustic characteristics.

• 설비공학논문집
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• 제22권8호
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• pp.562-566
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• 2010

Wind energy is one of the most general natural resources in the world. However, as of today, generating electricity out of wind energy is only available from big wind generator, Furthermore, an axial-flow turbine is the only way to produce electricity in the big wind generator. This paper is for the guidance of drawing impact fact about power turbine using cross-flow type transferring wind energy to electricity energy. It will find the ideal value which enables to make cross-flow power turbine(CPT) using computational fluid dynamics(CFD) code. This study tries to analyze the "Solidity" characteristics. We can find out turbine-blade number through CFD. CFD is using "Fluent_ver 6.3.16", and the data from its result will judge fan-blade performance through specific torque and specific power from each "Solidity" model. Based upon the above, we will make cross-flow power turbine of multi-blade centrifugal fan instead of axial-flow type.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.64-68
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• 2014

This paper is intended to provide experimental data for the design of the small VAWT(vertical axis wind turbine). Three types(lift, drag, and hybrid) of the blade of VAWT are tested with digital wind tunnel in this study. From the test, the relation of power coefficient and tip speed ratio for the blades are evaluated and compared each other depending on the blade type. Especially, the characteristics of hybrid blade which is shown to be expanded in the market without any logical data is proposed in the relation of power coefficient and tip speed ratio. It is shown that the hybrid blade can be used to make higher starting torque with trade off of degradation of power coefficient.

• 대한기계학회논문집B
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• 제36권5호
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• pp.465-475
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• 2012

본 연구는 두 가지 목표를 가지고 수행하였다. 하나는 수치해석과 Design-FOIL Pro.를 이용해 블레이드 에어포일 모델개발이고, 다른 하나는 이 모델을 Folding blade에 적용하는 것이다. 일반적으로 1MW이상 대형풍력터빈용 블레이드는 강풍시에 피칭제어로 풍향에 대해서 평형상태를 유지하여 로터를 회전시키지 않는 방법으로 블레이드의 손상을 방지 하였지만, 소형풍력터빈용 블레이드는 설비비, 유지비등 경제성을 이유로 피칭제어를 채택하지 않아 블레이드의 파손 문제가 심각하다. 그래서 본 연구에서는 유지보수가 필요 없고 강풍에서도 파손이 없는 Spring pack을 이용한 로터를 직접설계(Direct-Design) 방법으로 설계하여, 그 성능을 검증 하고 변화 풍속에 맞는 폴딩각을 이용해 강풍시에도 Wind turbine이 Cut-out 없이 계속발전을 유지할 수 있도록 하는 점에 집중 연구하고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• 제38권2호
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• pp.154-161
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• 2014

This research presents results of structural designs and evaluations for 3MW Wind Turbine Blade by FEM analysis. After the GFRP model was designed as a baseline model, failure check by Puck's failure criterion and buckling analysis were accomplished to verify safety of wind turbine blade in the critical design load case. Moreover, applicability of two kinds of carbon spar cap model, was studied by comparing total mass, price and tip deflection to the GFRP model. The results showed that the GFRP model had sufficient structural integrity in the critical design load case, and the carbon spar cap model could be a reasonable solution to reduce weights, tip deflections.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.191-193
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• 2006

The various wind turbines have been designed and developed for the century. The precision design of the blade and turbine system considering the wind circumstance is required for the high efficiency. In this paper, we investigated the output characteristics of the horizontal and vertical wind turbine related to the wind velocity. Furthermore we will intend to design the wind turbine blade adapted the urban wind circumstance.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.379-384
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• 2004

A prototype of 750 kW direct-drive wind turbine generator system, KBP-750D is under development in Korea. For the gearless, direct-drive prototype a synchronous generator with permanent magnets has been developed. The upwind 3-blade type machine employs variable speed and pitch control. The operating ranges of wind and rotor speed are 3 to 25 m/s and 9 to 25 rpm, respectively. The tip speed ratio of rotor blade is 7.5, designed for power coefficient 0.47, The blade pitch and torque are controlled with the predefined torque-speed curve according to the conditions of wind and public electric grid. This paper describes the outlines of primary components of KBP-750D.

• 한국항공운항학회지
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• 제25권2호
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• pp.63-68
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• 2017

In the present study, a wind tunnel test for a rotor-blade configuration was conducted to investigate a basic aerodynamic performance and a effect of the cross wind. The diameter of the configuration was 1.46 m and the test was carried out for both a clean and a tripped configurations. The boundary layer for the trip configuration was simulated by zig-zag tape and the test performed on constant-velocity and constant-rotational modes. It was shown that the test result for the tripped configuration reduces the maximum power coefficient by 9.4% ~ 12.1% compared to the clean one. Within $5^{\circ}$ of the flow angle, there is no significant loss of power, however, the coefficient is reduced by 5.3% ~ 36.7% in the range of $10^{\circ}{\sim}30^{\circ}$.

• 한국정보전자통신기술학회논문지
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• 제11권3호
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• pp.241-245
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• 2018

본 논문에서 주 블레이드를 V 형태로 설계하고 주 블레이드 각도와 풍속을 변화시켜 최상의 설계조건을 확인하고자 하였다. 주 블레이드 open angle을 $120^{\circ}$유지하고, 각도를 $30^{\circ}$로 변화시킨 sample2와 $60^{\circ}$로 변화시킨 sample3를 비교 하였을 때, sample2는 출력이 3.8[kW], 효율은 0.12로 측정되었고 sample3은 출력이 6.0[kW] 효율은 0.18로 측정되었다. 즉 sample3은 sample2보다 출력이 58%, 효율이 50% 상승되었다. 그리고 주 블레이드 open angle $120^{\circ}$, 각도를 $60^{\circ}$로 고정하여 풍속을 7[m/s]일 때 출력이 6.0[kW]으로 효율은 0.18로 측정되었고, 풍속을 10[m/s]로 변화 주었을 때 출력은 7.7[kW], 효율은 0.23으로 측정되었다. 즉 풍속이 높았을 때 출력은 28%, 효율은 83%가 상승되었다. 또한 sample4는 sample2보다 출력에서 103%, 효율에서 92%가 더 상승하였다.