• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.617-618
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• 2012

• New & Renewable Energy
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• v.8 no.1
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• pp.44-51
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• 2012

Due to a high tidal range of up to 10 m on the west coast of Korea, numerous tidal current projects are being planned and constructed. The turbine, which initially converts the tidal energy, is an important component because it affects the efficiency of the entire system. Its performance is determined by design variables such as the number of blades, the shape of foils, and the size of a hub. To design a turbine that can extract the maximum power on the site, the depth and duration of current velocity with respect to direction should be considered. Verifying the performance of a designed turbine is important, and requires a circulating water channel (CWC) facility. A physical model for the performance test of the turbine should be carefully designed and compared to results from computational fluid dynamics (CFD) analysis. In this study, a horizontal axis tidal current turbine is designed based on the blade element theory. The proposed turbine's performance is evaluated using both CFD and a CWC experiment. The sealing system, power train, measuring devices, and generator are arranged in a nacelle, and the complete TCP system is demonstrated in a laboratory scale.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.104-112
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• 2014

The counter-rotating approach on wind turbine has been recently put in interest for its certain advantages in both design and performance. This paper introduces a study on a counter-rotating wind turbine designed and modeled using NREL airfoils S822 and S823. The aims of the study is to evaluate and discover the performance of the counter-rotating system, and compares to that of single rotor turbine of same design using numerical simulation. The results show higher performance of the counter-rotating system compared with single rotor case at TSR 3 to 5 but lower performance at higher TSR. This is due to the interaction between upstream and downstream rotors. Thus, the counter-rotating turbine is more efficient at low rotor rotational speed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.512-515
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• 2009

This research describes on airfoil shape design, crucial to core technique and algorithm optimization for the wind turbine blade development. We grasped the parameter to define the airfoil shape in the wind turbine blade and aircraft, and the important performance characteristic of the airfoil. The airfoil shape function is selected by studying which is suitable for wind turbine blade airfoil development. The selected method is verified by to compare the generated airfoil shape with base airfoil. The new airfoils were created by the selecting shape function based on the well-known airfoil for wind turbine blades. In addition, we performed aerodynamic analysis about the generated airfoils by XFOIL and estimated the point of difference in the airfoil shape parameter using the aerodynamic performance results which is compared with basic airfoil. This result data applies to the fundamental research for a wind turbine blade optimization design and accomplished the aerodynamic analysis manual.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.38-44
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• 2011

The performance experiment was tested for the velocity compound turbine of turbopump which was the main part of 75 ton class liquid rocket engine. The seal is installed between the 1st rotor and the reversing vane to reduce the leakage flow. The turbine outlet pressure of the velocity compound turbine by changing the rotating speed was compared with that of baseline turbine with single rotor including the effect on the total performance.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.535-542
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• 2011

To utilizing CFX V12.0.l, internal flow characteristics of denture high-speed air turbine hand-piece unit was identified, in order to analyze the performance of the torque values were compared. In order to find out the difference of torque by mash values, under steady condition, performed grid convergence test. It compared theoretical torque with torque through flow analysis. To describe the motion of turbine blade was used to immerged solid method. Depending on the location of the turbine blade were calculated from five case. Maximum and minimum values of turbine blades was analyzed. To analyze the performance of the torque values were compared with speed of turbine blade.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.5
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• pp.326-333
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• 2009

Design life-time of a wind turbine is required to be at least 20 years. In the meantime, the wind turbine will experience a lot of load cases such as extreme loads and fatigue loads which will include several typhoons per year and extreme gusts with 50 years recurrence period as well as endless turbulence flow. Therefore, IEC61400-1 specifies design load cases to be considered in the wind turbine design and requires the wind turbine to withstand the load cases in various operational situations. This paper investigates the ultimate loads which the wind turbine will experience for 20 years and their characteristics based on the IEC61400-1 using an aero-elastic software, GH-Bladed. And the performance characteristics of a wind turbine such as electrical power generation and annual energy yield are also investigated.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2880-2885
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• 2008

Design lifttime of a wind turbine is required to be at least 20 years. In the meantime, the wind turbine will experience a lot of load cases such as extreme loads and fatigue loads which will include several typhoons per year and extreme gusts with 50 years recurrence period as well as endless turbulence flow. Therefore, IEC61400-1 specifies design load cases to be considered in the wind turbine design and requires the wind turbine to withstand the load cases in various operational situations. This paper investigates the ultimate loads which the wind turbine will experience for 20 years and their characteristics based on the IEC61400-1 using an aero-elastic software, GH-Blade. And the performance characteristics of a wind turbine such as electrical power generation and annual energy yield are also investigated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1455-1460
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• 2014

Wind turbine generators were designed on general regulations of wind condition. At real situations, it could be different from the design conditions. There are many control methods and definitions of transient region, because an efficient wind turbine generator control logic is the important matter in generator performance and annual energy production at real conditions. In this document, the power generation sensitivity for wind speed and turbulence intensities was defined to know the sensitive transient region. Wind conditions are applied for the ranges of 7~10m/s mean wind speed and 14~20% turbulence intensity. The sensibility of HR-D86 wind generator was increased in transient region(8~10m/s) on power curve diagram through a torque control to a pitch control. And then GH-bladed simulations was performed for performance analysis of the torque mode switching in transient region on 2MW direct drive wind generator(HR-D86) which is designed IEC class II for onshore. Through the sensitivity and performance analysis, the sensitivity for real wind condition could be the performance index for an wind generator. And the torque mode switching in transient region can increase the mean power generation on HR-D86 wind turbine generator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.99-105
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• 2002

The performance test of an axial-type turbine is carried out with various axial gap distances between the stator and rotor. The turbine is operated at the low pressure and speed, and the degree of reaction is 0.373 at the mean radius. The axial-type turbine consists of ons-stage and 3-dimensional blades. The chord length of rotor is 28.2mm and mean diameter of turbine is 257.56mm. The power of turbo-blower for input power is 30kW and mass flow rate is $340m^3$/min at 290mmAq static-pressure. The RPM and output power are controlled by a dynamometer connected directly to the turbine shaft. The axial gap distances are changed from a quarter to three times of stator axial chord length, and performance curves are obtained with 9 different axial gaps. The efficiency varies about 8% of its peak value due to the variation of axial gap on the same non-dimensional mass flow rate and RPM, and experimental results show that the optimum axial gap is 1.6-1.9Cx.