• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.330-335
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• 2016

In this study, aerodynamic characteristics of the blades of a helical-type vertical axis wind turbine(VAWT) have been investigated. For this purpose, a 100-W helical-type vertical axis wind turbine was designed using a design formulae, and a 3D computational fluid dynamics analysis was performed considering wind tunnel test conditions. Through the results of the analysis, the aerodynamic power output and flow characteristics of a helical blade were confirmed. In order to validate the aerodynamic power output obtained through the analysis, a wind tunnel test was performed by using a full-scale helical-type vertical axis wind turbine. The 3D analysis technique was validated by comparing its results with those obtained from the wind tunnel test.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.289-292
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• 2001

A Dual rotor turbines HAWT/VAWT combined wind turbine system that can drastically enhance the power production capability compared to conventional Single Rotor Turbine HAWT system. The combined system that takes advantage of strong point of both horizontal and vertical Axis wind turbine system developed by a venture firm : KOWINTEC of Chonbuk National University. The HAWT/VAWT hybrid system has been successfully field tested and commercial operation since Feb. 12, 2001 in Hae-chang rest park, Bu-an county near the Sae Man-Kum Sea Dike. This paper will briefly describe the field test results performance and a special aerodynamic structure with bevel-planetary gear box of Dual Rotor Wind Turbine system.

• Wind and Structures
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• v.22 no.5
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• pp.595-616
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• 2016

Providing high starting torque and efficiency simultaneously is a significant challenge for vertical axis wind turbines (VAWTs). In this paper, a new approach is studied in order to modify VAWTs performance and cogging torque. In this approach, J-shaped profiles are exploited in the structure of blades by means of eliminating the pressure side of airfoil from the maximum thickness toward the trailing edge. This new profile is a new type of VAWT airfoil using the lift and drag forces, thereby yielding a better performance at low TSRs. To simulate the fluid flow of the VAWT along with J-shaped profiles originated from NACA0018 and NACA0030, a two-dimensional computational analysis is conducted. The Reynolds Averaged Navier-Stokes (RANS) equations are closed using the two-equation Shear Stress Transport (SST) turbulence model. The main objective of the study is to investigate the effects of J-shaped straight blade thickness on the performance characteristics of VAWT. The results obtained indicate that opting for the higher thickness in J-shaped profiles for the blade sections leads the performance and cogging torque of VAWT to enhance dramatically.

• The KSFM Journal of Fluid Machinery
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• v.19 no.4
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• pp.43-47
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• 2016

Vertical axis wind turbine, despite of its limit in power efficiency, the simplicity in structure and maintenance is a competitive factor that keeps this type of turbine in the game until nowadays. Continuous solutions have been given to handle its major weakness and the use of omni-directional guide vane is an considerable one. In this paper, a 5kkW scale Savonius-based wind turbine enhanced with such guide vane system was design and studied. Together with reasonable blade design, the wind turbine shows promising performance compared with basic design while maintaining its original advantages.

• Journal of Advanced Engineering and Technology
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• v.11 no.4
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• pp.237-243
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• 2018

The purpose of this study is to develop a vertical wind turbine with antenna structure in microgird environment. Computational fluid dynamics (CFD) was used to calculate the basic aerodynamic performance. The pressure resulted from CFD analysis has been mapped on the surface of wind turbine as load condition and the Fluid Structure Interaction (FSI) was applied. The stability of the wind turbine was confirmed by checking the deformation and internal stress of wind turbine by wind force.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.2
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• pp.114-123
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• 2018

Wind power tower (WPT) has been used to augment the performance of vertical axis wind turbine (VAWT). However, the performance of the WPT depends on several design parameters, such as inner and outer radius, or number of guide walls. Therefore, an experimental study was conducted to investigate efficient design parameters on the WPT. A wind tunnel was utilized and its test section dimension was 2m height and 2.2m width. One story model of the WPT was manufactured with seven guide walls and a VAWT was installed within the WPT. Three different sizes of guide walls were applied to test with various design parameters. The power coefficients were measured along the azimuthal direction in a state of equal inlet velocity in order to compare its performance relatively. The experimental results showed that the gap between the inner radius of the WPT and the rotating radius of the VAWT was a major parameter to improve the performance of VAWT within the WPT.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.4
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• pp.13-20
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• 2006

The inherent problem of a Darrieus wind turbine is its inability to self-start. Usually, a motor is used to provide angular acceleration until lift forces are produced in the airfoil blades or up until the turbine can already sustain its speed on its own. This paper describes a method of improving the self-starting of an H-type Darrieus vertical axis wind turbine (VAWT) by incorporating a helical Savonius turbine thus utilizing a drag-lift combination. The effect of each turbine in the combination relative to each other is investigated by testing a prototype windmill consisting of three NACA 0015 airfoil blades combined with a Savonius rotor with a helix angle of 180 degrees and whose swept area equals 30% of the entire turbine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1203-1204
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• 2010

• The KSFM Journal of Fluid Machinery
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• v.16 no.4
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• pp.22-27
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• 2013

The purpose of this paper is to perform the structural design of the small scale vertical-axis wind turbine (VAWT) blade using a response surface method(RSM). First, the four design factors that have a strong influence on the structural response of blade were selected. Analysis conditions were calculated by using the central composite design(CCD), which is a typical design of experiment for the response surface method(RSM). Also, the significance of the central composite design(CCD) was verified using analysis of variance(ANOVA). The finite element analysis was performed for the selected analytical conditions for the application of response surface method(RSM). Finally, a optimization problem was solved with a objective function of blade weight and a constraint of allowable stress to achieve a optimal structural design of blade.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.88-92
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• 2017

Owing to the depletion of fossil energy, wind power is attracting attention as a promising environmentally friendly alternative energy source, because it is abundant, renewable, and non-polluting. Wind turbines are divided into horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) according to the direction of the rotating shaft. VAWTs have a low power generation efficiency, but are not affected by the wind direction and, thus, no yaw system is required and their structure is simple. Small VAWTs are attracting much attention because they can generate power even at low wind speeds. In this study, the output voltages and output currents of small VAWTs with gyromill type, hinge type and double door type blades capable of generating power even at low wind speeds were analyzed at variable wind speeds in the range of 1~11 m/s. At the maximum wind speed of 11m/s, the application of the double door type blades achieved 67% and 9% higher wind turbine output voltages than that of the gyromill type and hinge type blades, respectively. As regards the wind turbine output currents, the application of the double door type blades gave rise to 93% and 5% higher results than that of the gyromill type and hinge type blades, respectively. Through this study, the excellent output characteristics and commercialization potential of the double door type blades, which can generate power both at low and high wind speeds, were confirmed.