• New & Renewable Energy
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• v.3 no.3
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• pp.54-62
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• 2007

The present paper describes the scale effect correction methods for scaled NREL Phase VI wind turbines by using CFD[computational fluid dynamics). For the corrections of wind turbine scale effect, various researches on the helicopter rotor scale effect were investigated and the feasibility study of the methods was performed to correct wind turbine scale effect. The present paper also introduces scale effect correction methods based on two dimensional lift slope. In order to test the present method, performance analyses of NREL Phase VI wind turbines under various scale conditions were carried out and new correction method was applied. Granting that the new correction method is valid only above Reynolds No. 100,000, it showed reasonable agreement between model and full scale wind turbines in the linear torque region.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.273-279
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• 2014

In this paper, wind tunnel tests of a scaled wind turbine have been performed to investigate the effects of turbulent intensity of oncoming flow on turbine wake field. The scaled turbine model was carefully designed to satisfy the similarity conditions. The wind velocities and turbulent intensities were measured using hotwire anemometer in order to compare with existing wake model. It was found from the tests that the existing wake models well fit with test results at turbulent flow rather than at uniform flow. Finally modified wake model has been proposed based on the measured data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.8
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• pp.75-82
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• 2013

We propose a fiber grating sensor system for condition monitoring of large scale wind turbine blades. For the feasibility test of the proposed sensor system, a down-scaled wind turbine has been constructed and experimented. Fiber grating sensors were attached on a blade surface for distributed strain and temperature measurements. An optical rotary joint was used to transmit optical signals between the FBG sensor array and the signal processing unit. Instead of broadband light source, we used a wavelength-swept fiber laser to obtain high output power density. A spectrometer demodulation is used to alleviate the nonlinear wavelength tuning problem of the laser source. With the proposed sensor system we could measure dynamic strain and temperature profiles at multi-positions of rotating wind turbine blades.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.391-394
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• 2007

Wind turbine gearbox is a complex mechanical system that includes gear trains, shafts, bearings, and gearbox housings. All these components are interacting with each other therefore it is important to assess the whole performance by considering the individual component design. In this paper, the performance assessment of 2MW wind turbine gearbox was conducted under various operating conditions at test bench and test result was compared with the design calculation.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.2
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• pp.199-209
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• 2013

This paper presents the model test results of 3 new spar platforms which were developed based on the OC3-Hywind spar to support a 5-MW wind turbine. By changing the shape but keeping both volume and mass of OC3-Hywind spar platform, those platforms were expected to experience different hydrodynamic and hydrostatic loads. The scale models were built with a 1/128 scale ratio. The model tests were carried out in waves, including both rotating rotor effect and mean wind speed. The characteristic motions of the 3 new models were measured; Response Amplitude Operators (RAO) and significant motions were calculated and compared with those of OC3-Hywind.

• New & Renewable Energy
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• v.5 no.2
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• pp.31-38
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• 2009

The performance test of a wind turbine in a wind farm is generally carried out by the owner to verify the power curve of the wind turbine given by the turbine manufacturer. The international electro-technical commission provides the IEC 61400-12-1 standard on "Power performance measurements of electricity producing wind turbines". By using this code, one can easily find the suitable met-mast (meteorological mast) location for the wind data whether a wind farm is potential or already built. In this paper, the valid sectors for wind turbines installed in the HanKyoung wind farm, south-west in Jeju island are analyzed on the basis of the code by considering the wind farm layout. Among these sectors, the optimal met-mast location is presented for the power curve verification of the wind farm.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.34.2-34.2
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• 2011

Wind guide can be installed on the top of buildings to collect wind. In this study, optimum shape of wind guide is developed, and proposed to combinate with the vertical wind turbine. Impact of parameters for wind guide is analyzed with several cases planned by Taguchi test plan. Front angle, rear angle, and roof angle are selected as key variables and changed into four different levels. By the experimental plan, totally, 64 cases are reduced to 16 cases of analysis. With optimum design of wind guide, the installed vertical axis wind turbines can be operated with maximum power output.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.125-130
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• 2004

This study proposes a development for the l-kW class small wind turbine system, which is applicable to relatively low wind speed region like Korea and has the variable pitch control mechanism. In the aerodynamic design of the wind turbine blade, parametric studies were carried out to determine an optimum aerodynamic configuration which is not only more efficient at low wind speed but whose diameter is not much larger than similar class other blades. A light composite structure, which can endure effectively various loads, was newly designed. In order to evaluate the structural design of the composite blade, the structural analysis was performed by the finite element method. Moreover both structural safety and aerodynamic performance were verified through the prototype test.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.85-91
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• 2015

Wind turbine blades represent a key component of wind turbines, which extract energy from the wind. In the present study, the structural design of a small wind turbine blade is undertaken using a numerical analysis. The reliability of numerical results is verified through a comparison with the full-scale structural test data of a current blade. To modify the blade design, the blade was divided into several sections and the effect of the thickness of each section was investigated in a numerical analysis. Finally, the modified blade was designed with a lightweight and high-strength.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.401-407
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• 2004

This study proposes a interim development result for the l-㎾ class small wind turbine system, which is applicable to relatively low wind speed regions like Korea and has the variable pitch control mechanism. In the aerodynamic design of the wind turbine blade, parametric studies were carried out to determine an optimum aerodynamic configuration which is not only more efficient at low wind speed but whose diameter is not much larger than similar class other blades. A light composite structure, which can endure effectively various loads, was newly designed. In order to evaluate the structural design of the composite blade, the structural analysis was performed by the finite element method. Moreover both structural safety and stability were verified through the full-scale structural test.