Performance assessment of an innovative Gurney flap for straight-bladed vertical axis wind turbine

2021 ◽  
Author(s):  
Qingsong Liu ◽  
Weipao Miao ◽  
Qi Ye ◽  
Chun Li
Keyword(s):  
Wind Turbine ◽  
Performance Assessment ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Gurney Flap

Performance Improvements for a Vertical Axis Wind Turbine by Means of Gurney Flap

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Yan Yan ◽  
Eldad Avital ◽  
John Williams ◽  
Jiahuan Cui
Keyword(s):  
Wind Turbine ◽  
Stokes Equations ◽  
Numerical Study ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Performance Improvements ◽  
Gurney Flap

Abstract A numerical study was carried out to investigate the effects of a Gurney flap (GF) on the aerodynamics performance of the NACA 00 aerofoil and an associated three-blade rotor of a H-type Darrieus wind turbine. The flow fields around a single aerofoil and the vertical axis wind turbine (VAWT) rotor are studied using unsteady Reynolds-averaged Navier–Stokes equations (URANS). The height of GF ranges from 1% to 5% of the aerofoil chord length. The results show that the GF can increase the lift and lift-to-drag ratio of the aerofoil as associated with the generation of additional vortices near the aerofoil trailing edge. As a result, adding a GF can significantly improve the power coefficient of the VAWT at low tip speed ratio (TSR), where it typically gives low power production. The causing mechanism is discussed in detail, pointing to flow separation and dynamic stall delay.

Effect of geometric parameters of Gurney flap on performance enhancement of straight-bladed vertical axis wind turbine

2021 ◽  
Vol 165 ◽  
pp. 464-480
Author(s):  
Haitian Zhu ◽  
Wenxing Hao ◽  
Chun Li ◽  
Shuai Luo ◽  
Qingsong Liu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Performance Enhancement ◽  
Vertical Axis ◽  
Geometric Parameters ◽  
Vertical Axis Wind Turbine ◽  
Gurney Flap

scholarly journals Aerodynamic Characteristics of Airfoil and Vertical Axis Wind Turbine Employed with Gurney Flaps

2021 ◽  
Vol 13 (8) ◽  
pp. 4284
Author(s):  
Yosra Chakroun ◽  
Galih Bangga
Keyword(s):  
Wind Turbine ◽  
Numerical Solutions ◽  
Vertical Axis ◽  
Power Production ◽  
Aerodynamic Characteristics ◽  
Maximum Height ◽  
Vertical Axis Wind Turbine ◽  
Time Step ◽  
Gurney Flaps ◽  
Gurney Flap

In the present studies, the effects of Gurney flaps on aerodynamic characteristics of a static airfoil and a rotating vertical axis wind turbine are investigated by means of numerical approaches. First, mesh and time step studies are conducted and the results are validated with experimental data in good agreement. The numerical solutions demonstrate that the usage of Gurney flap increases the airfoil lift coefficient CL with a slight increase in drag coefficient CD. Furthermore, mounting a Gurney flap at the trailing edge of the blade increases the power production of the turbine considerably. Increasing the Gurney flap height further increases the power production. The best performance found is obtained for the maximum height used in this study at 6% relative to the chord. This is in contrast to the static airfoil case, which shows no further improvement for a flap height greater than 0.5%c. Increasing the angle of the flap decreases the power production of the turbine slightly but the load fluctuations could be reduced for the small value of the flap height. The present paper demonstrates that the Gurney flap height for high solidity turbines is allowed to be larger than the classical limit of around 2% for lower solidity turbines.

scholarly journals The effect of gurney flap on flow characteristics of vertical axis wind turbine

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040107
Author(s):  
Taurista Perdana Syawitri ◽  
Yu-Feng Yao ◽  
Jun Yao ◽  
Budi Chandra
Keyword(s):  
Wind Turbine ◽  
Lift Coefficient ◽  
Flow Characteristics ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Trailing Edge ◽  
Eddy Simulation ◽  
Moment Coefficient ◽  
Gurney Flap

Recently, the Gurney Flap (GF) has been used to improve the performance of Horizontal Axis Wind Turbine (HAWT) by enhancing its lift coefficient. Compared to HAWT, research on GF application for Vertical Axis Wind Turbine (VAWT) is very limited. Moreover, most works studied a GF geometry attached to the trailing edge of a stationary airfoil, without considering the rotating effect experienced by VAWT. For this reason, a three-straight-bladed VAWT rotating blade with GF is studied by transient RANS simulation together with a stress-blended eddy simulation (SBES) turbulence model to investigate the GF height effect and the flow characteristics near the blade trailing edge. Results have shown that by introducing the blade rotating, an optimum GF height is found to be 3% of the blade chord, slightly higher than 2% chord in a stationary airfoil case. In addition, the presence of GF can delay deep stall of VAWT blades, thus eliminating negative instantaneous moment coefficient and improving the turbine performance.

A Note on the Decomposition of Aerodynamic Forces Induced by A Wind Turbine Flaps

2020 ◽  
Vol 36 (5) ◽  
pp. 585-593
Author(s):  
Y. Y. Niu ◽  
P. J. Shih ◽  
S. C. Kong
Keyword(s):  
Wind Turbine ◽  
Aerodynamic Force ◽  
Rotational Velocity ◽  
Angular Acceleration ◽  
Surface Friction ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Gurney Flap ◽  
Force Element ◽  
Element Theory

ABSTRACTIn this study, the aerodynamic characteristics of a vertical-axis wind turbine blade coupled with a high-lift device, such as the Gurney flap at the trailing edge, are investigated. For numerical analysis, the force element theory is used to understand how the Gurney flap influences the force evolution of the lift-type vertical-axis wind turbine. This study shows that the lift and drag can be respectively approximated into four elements, which are induced by volume vorticity, rotational velocity, angular acceleration and surface friction of the flow around the blades. Based on the perspective of the force element theory, the present simulation provides a clear picture of how the Gurney flap influences the formation of the aerodynamic force elements during a rotational cycle for a vertical-axis wind turbine. Simulation results show that the contributions mainly result from the surface vorticities, the rotational acceleration of the airfoil, and the acceleration of the surface.

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