• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.661-668
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• 2015

We present a design methodology for horizontal-axis tidal turbine blades based on blade element momentum theory, which has been used for aerodynamic design and power-performance analysis in the wind-energy industry. We design a 2-blade-type 1 MW HATT blade, which consists of a single airfoil (S814), and we present the detailed design parameters in this paper. Tidal turbine blades can experience cavitation problems at the blade-tip region, and this should be seriously considered during the early design stage. We perform computational fluid dynamics (CFD) simulations considering the cavitation model to predict the power performance and to investigate the flow characteristics of the blade. The maximum power coefficient is shown to be about 47 under the condition where TSR = 7, and we observed cavitation on the suction and pressure sides of the blade.

• Journal of Energy Engineering
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• v.29 no.1
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• pp.34-43
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• 2020

A study has been done for self-starting torque of vertical axis wind turbine blade. It is especially concentrated to evaluate the torque coefficient before starting rotation. Two different aerofoils(AMI903 and AMI904) are proposed to benchmark the possible best blade(supercritical airfoil) for self-starting performance. Torque coefficients in the tangential direction of rotation are given with respect to the angle of attack in terms of drag coefficient and lift coefficient. Torque coefficient shows that the effect of Reynolds number is minimal. The thicker blade(AMI904) between two different proposed airfoils has bigger torque coefficient, which is attributed to lower lift coefficient and higher drag coefficient.

• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.1-9
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• 2020

In this paper, the effects of the delta winglet vortex generator, the airfoil vortex generator and the guide vanes on the friction factor and the Colburn factor in the fin-tube flow were studied. The vortex generator and guide vane were non-dimensionalized based on the channel height and tube diameter, and locations were selected according to the authors' suggestions. The Reynolds number based on the inlet velocity and the tube diameter was selected in the range of 1400-8000. As a result, the friction factor resulted in a 4.7% decrease in guide vanes at the Reynolds number 8000 over the conventional fin-tube, and the Colburn factor resulted in a 33% increase in the delta winglet vortex generator at the Reynolds number 3800 over the conventional fin-tube.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.485-492
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• 2021

The wind turbines with a rated capacity of 50kW or less are generally considered as small class. Small wind turbines are an attractive alternative for off-grid power system and electric home appliances, both as stand-alone application and in combination with other energy technologies such as energy storage system, photovoltaic, small hydro or diesel engines. The research objective is to develop the 50kW scale wind turbine blades in ways that resemble as closely as possible with the construction and methods of utility scale turbine blade manufacturing. The mold process based on wooden form is employed to create a hollow, multi-piece, lightweight design using carbon fiber and fiberglass with an epoxy based resin. A hand layup prototyping method is developed using high density foam molds that allows short cycle time between design iterations of aerodynamic platforms. A production process of five blades is manufactured and key components of the blade are tested by IEC 61400-23 to verify the appropriateness of the design. Also, wind system with developed blades is tested by IEC 61400-12 to verify the performance characteristics. The results of blade and turbine system test showed the available design conditions for commercial operation.