• Journal of the Korean Society of Visualization
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• v.17 no.1
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• pp.43-52
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• 2019

'Ionic wind' is phenomenon induced by corona discharge which occurs when large electric potential is applied to electrodes with high curvature. The ionic wind has advantage that it could generate forced convective flow without any external energy like separate pump. In this study, 'pin-mesh' arrangement is utilized for experiments. First, optimization of configuration is conducted with local momentum of ionic wind behind the mesh. Empirical equation for prediction about velocity profile was derived using the measured results. Secondly, the enhancement of mass transfer rate of acetone with ionic wind was analyzed. Also, the drying efficiency using a fan which has same flow rate was compared with ionic wind for identification of additional chemical reaction. At last, the drying process of organic solvent was visualized with image processing. As a result, it was shown that the use of ionic wind could dry organic matter four times faster than the natural condition.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.64-67
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• 2005

A vibration monitoring system for a small size wind turbine (WIT) is established and operated. The monitoring system consists of monolithic integrated chip accelerometer for vibration monitoring, anemometers for wind data acquisition and auxiliary sensors for atmospheric data. Using the monitoring system, vibration response of a 6kW stand alone WIT generator is investigated. Acceleration data of the WIT tower under various operation condition is acquired in real time using LabVIEW and the data are remotely transferred from the test site to the laboratory in school by internet. Vibration response characteristics of the tower structure are diagnosed in the aspect of stability of W/T. Wind data and electrical power performance are also investigated with the stability problem.

• Journal of computational fluids engineering
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• v.10 no.1
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• pp.45-50
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• 2005

A fundamental understanding of the flow around the wind turbine is important to investigate the performance of new type of wind turbine. This study presents the simulation of three dimensional flow fields around the Darius wind turbine as an example. Incompressible Navier-Stokes equations are used for this simulation. The rotating coordinate system that rotates in the same speed of the turbine is used in order to simplify the boundary condition on the blades. Additionally, the boundary fitted coordinate system is employed in order to express the shape of the blades precisely. Fractional step method is used to solve the basic equations. Third order upwind scheme is chosen for the approximation of the non-linear terms since it can compute the flow field stably even at high Reynolds number without any turbulence models. The flow fields obtained in this study are highly complex due to the three dimensionality and are visualized effectively by using the technique of the computer graphics.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.83-87
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• 2004

A reduced structure model of a wind turbine generator is designed and manufactured. Mode data are obtained by modal testing and analytical method. Vibration response is measured and investigated under various speed condition by using a waterfall plot. Possibility of severe resonance is observed and the mechanism is explained by using the mode data. Simplified theoretical model gives the 1st resonance frequency of wind turbine structure model. The theoretical model can be applied in the design stage of the wind turbine structure to avoid the severe resonance problem.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.493-495
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• 2010

A three-dimensional flow simulation is performed to investigate the flow field in the ski resort on complex terrain. The present paper aims to study the wind effects of mountainous terrain on the gondola safety. Strong wind happens in the ski resort on the mountain by complex terrain and it causes the dangerous accident of gondola. A digital map around the ski resort area is used to model the actual complex terrain for a 3-D analysis domain. Wind direction and speed to be used as a boundary condition are taken from local meteorological reports. The numerical results show details of the velocity distribution around a ski resort. From the results, we can suggest the modification of the installation of gondola for the safety due to strong wind.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.53-59
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• 2010

Preliminary design of a ground plate, a device installed close to the aircraft model for wind tunnel test to simulate the ground effect, was performed by a numerical simulation. A two-dimensional numerical study was performed initially to decide the optimal leading edge and flap configurations. Then, three-dimensional studies were conducted to decide the optimal flap deflection angle for pressure distribution reduction since the plate and the plate supporting system generate static pressure difference between the upper and lower flow regions. Three-dimensional simulation additionally studied the effect of the clearance between the plate and the wind tunnel side wall. For the efficiency of computation, half model was simulated and a symmetric boundary condition was applied on the center plane. Based on the preliminary design, a ground plate was designed, manufactured and tested at the Korea Aerospace Research Institute(KARI) wind tunnel. The measured pressure differences versus flap deflection angle agreed well with the predicted results.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.41.2-41.2
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• 2011

NREL NWTC Deside codes are analyzed and introduced to develop the system performance simulation program for wind turbine generator systems. In this paper, The AirfoilPrep generating the airfoil data, the IECWind generating hub-height wind data with extreme condition following IEC 61400-1, the TurbSim generating stochastic full-field turbulent wind data, the PreComp calculating structural and dynamic properties of composite blade and the BModes making mode shapes of blade and tower are explained respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.33-37
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• 2004

Photovoltaic energy and wind energy are highly dependent on the season, time and extremely intermittent energy sources. Because of these reasons, in view of the reliability the photovoltaic and the wind power generation system have many problems(energy conversion, energy storage, load control etc.) comparing with conventional power plant. In order to solve these existing problems, hybrid generation system composed of photovoltaic(500W) and wind power system(400W) was suggested But, hybrid generation system cannot always generate stable output due to the varying weather condition So, the auxiliary power compensation unit that uses elastic energy of spiral spring was added to hybrid generation system for the present study. It was partly confirmed that hybrid generation system was generated a stable outputs by spiral spring was continuously provided to load.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.631-638
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• 2003

The wind turbine blade is the equipment converted wind into electric energy. The effect of the blade has influence of the output power and efficiency of wind turbine. The design of blade is considered of lift-to-drag ratio, structure, a condition of process of manufacture and stable maximum lift coefficient, etc. This study is used the simplified method for design of the aerodynamic blade and aerodynamic analysis used blade element method. This process is programed by delphi-language. The program has any input values such as tip speed ratio, blade length, hub length, a section of shape and max lift-to-drag ratio. The program displays chord length and twist angle by input value and analyzes performance of the blade.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.770-771
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• 2007

Wind power plant is based on the wind energy so the active power is frequently changed and connected to grid according with wind condition. These characteristics are bed effect to distribution line. On this reserch, we want to analyze the quality of electric power synchro/asynchronous generation system in Dae Kwan Ryung wind farm. The contents of analysis are active/reactive power variation and total demand distortion and transiency and sag/swell phenomena. we hope this research can contribute to the power quality improvement.