• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.88-89
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• 2002

The aims of this study is to realize the structural design for development of a medium scale E-glass/epoxy composite wind turbine blade for a 750KW class horizontal axis wind turbine system. In this study, the various load cases specified by the IEC61400-1 international specification and GL Regulations for the wind energy conversion system were considered, and a specific composite structure configuration which can effectively endure various loads such as aerodynamic and centrifugal loads, loads due to accumulation of ice, hygro-thermal and mechanical loads was proposed. In order to evaluate the structure, the structural analysis for the composite wind turbine blade were peformed using tile finite element method(FEM). In the structural design, the acceptable blade structural configuration was determined through the parametric studies, and the most dominant design parameters were confirmed. In the stress analysis using the FEM, it was confirmed that the blade structure was safe and stable in any various load cases Moreover the safety of the blade root joint with insert bolts, newly devised in this study, was checked against the design fond and the fatigue.

• Journal of Wind Energy
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• v.2 no.1
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• pp.82-89
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• 2011

his dissertation is on power control system for MW-class wind turbine. Especially, the control purpose is reduction in electrical power and rotor speed. The base control structure is power curve tracking control using variable speed variable pitch operational type. For the reduction of fluctuations, more control algorithm is needed in above rated wind conditions. Because general pitch control system is low dynamic response as compared with the wind speed change. So, this paper introduces about the pitch feed forward control to minimize fluctuations of the electrical power and rotor speed. To maintain rated electrical power, the algorithm of feed forward control adds feed forward pitch amount to the pitch command of power curve tracking control. The effectiveness of the feed forward control is verified through the simulation.

• Composites Research
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• v.25 no.2
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• pp.54-61
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• 2012

In this study, a specific structural design procedure for 2 MW class glass/epoxy composite wind turbine system towers is newly proposed through load case study, trade-off study, optimal structural design and structural analysis. Optimal tower design is very important because its cost is about 20% of the wind turbine system's cost. In the structural design of the tower, three kinds of loads such as wind load, blades, nacelle and tower weight and blade aerodynamic drag load should be considered. Initial structural design is carried out using the netting rule and the rule of mixture. Then the structural safety and stability are confirmed using a commercial finite element code, MSC NASTRAN/PATRAN. The finally proposed tower configuration meets the tower design requirements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.201-208
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• 2009

Recently, the wind energy has been widely used as a renewable energy resource due to lack and environmental issues of the mostly used fossil fuel. This work is to develop a 500W class small wind turbine blade which will be applicable to relatively low speed region like Korea and for the domestic use. For this blade a high efficiency wind turbine blade was designed with the proposing aerodynamic design procedure, and a light and low cost composite structure blade was designed considering fatigue life. Structural analyses including load case study, stress, deformation, buckling and vibration analysis were performed using the Finite Element Method. The fatigue life was estimated using the load spectrum analysis and the Miner rule. In order to evaluate the designed blade, the structural and aerodynamic performance tests were carried out, and the test results were compared with the analysis results.

• The KSFM Journal of Fluid Machinery
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• v.14 no.2
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• pp.52-58
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• 2011

In this study, the design and verification of 6 kW class lift-type vertical-axis wind turbine (VAWT) has been conducted using advanced CAE technique based on computational fluid dynamics (CFD), finite element method (FEM), and computational structural dynamics (CSD). Designed aerodynamic performance of the VAWT model is tested using unsteady CFD method. Designed structural safety is also tested through the evaluation of maximum induced stress level and resonance characteristics using FEM and CSD methods. It is importantly shown that the effect of master eccentricity due to rotational inertia needs to be carefully considered to additionally investigate dynamic stress and deformation level of the designed VAWT system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.663-670
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• 2011

In this study, the design and verification of 6kW class lift-type vertical-axis wind turbine (VAWT) has been conducted using advanced CAE technique based on computational fluid dynamics (CFD), finite element method (FEM), and computational structural dynamics (CSD). Designed aerodynamic performance of the VAWT model is tested using unsteady CFD method. Designed structural safety is also tested through the evaluation of maximum induced stress level and resonance characteristics using FEM and CSD methods. It is importantly shown that the effect of master eccentricity due to rotational inertia needs to be carefully considered to additionally investigate dynamic stress and deformation level of the designed VAWT system.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.94-99
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• 2023

Recently, renewable energy has been widely used as a source of wind energy and solar energy due to the shortage of fossil fuels and environmental problems. Against this backdrop, wind energy is emerging as an important energy source, and the wind power market is showing rapid growth worldwide. In this study, a high-efficiency wind turbine blade was designed with an integrated blade aerodynamic design for prior research on separate blades. The blade airfoil was applied as NACA 4418, and it was verified by comparing it with the analysis results to evaluate the newly designed blade.

• 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).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.616-620
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• 2009

Modern wind turbines have been mainly erected in region where earthquake are rare or normally weak, especially Korea was thought as safety zone from earthquake. But recently, the earthquake occurs more and more frequently. So, the wind turbine design is required the structural and functional stability under the earthquake. The earthquake can influence normal operation, even if a weak earthquake. There are two ways to review the design under earthquake using Computer Applied Engineering (CAE). One is the Response Spectrum Analysis (RSA) the other is Time History Analysis (THA). In this research, dynamic response on time is obtained under the earthquake by taking into account ground accelerogram consistent with the relevant standards applied to the turbine foundation.

• The KSFM Journal of Fluid Machinery
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• v.11 no.4
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• pp.22-31
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• 2008

In this study, computer applied engineering (CAE) techniques are fully used to conduct structural and dynamic analyses of a huge composite rotor blade. Computational fluid dynamics is used to predict aerodynamic load of the rotating wind-turbine blade model. Static and dynamic structural analyses are conducted based on finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results for aerodynamic load, static stress, buckling and dynamic analyses are presented and characteristics of structural behaviors are investigated herein.