Variable pitch control for vertical-axis wind turbines

2018 ◽  
Vol 42 (2) ◽  
pp. 128-135 ◽  
Author(s):  
S Horb ◽  
R Fuchs ◽  
A Immas ◽  
F Silvert ◽  
P Deglaire
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Variable Pitch ◽  
Pitch Control

NENUPHAR aims at developing the next generation of large-scale floating offshore vertical-axis wind turbine. To challenge the horizontal-axis wind turbine, the variable blade pitch control appears to be a promising solution. This article focuses on blade pitch law optimization and resulting power and thrust gain depending on the operational conditions. The aerodynamics resulting from the implementation of a variable blade pitch control are studied through numerical simulations, either with a three-dimensional vortex code or with two-dimensional Navier-stokes simulations (two-dimensional computational fluid dynamics). Results showed that the three-dimensional vortex code used as quasi-two-dimensional succeeded to give aerodynamic loads in very good agreement with two-dimensional computational fluid dynamics simulation results. The three-dimensional-vortex code was then used in three-dimensional configuration, highlighting that the variable pitch can enhance the vertical-axis wind turbine power coefficient ( Cp) by more than 15% in maximum power point tracking mode and decrease it by more than 75% in power limitation mode while keeping the thrust below its rated value.

Two-Dimensional Computational Fluid Dynamics Study on the Performance of Twin Vertical Axis Wind Turbine With Deflector

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Yichen Jiang ◽  
Peidong Zhao ◽  
Li Zou ◽  
Zhi Zong ◽  
Kun Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Energy Utilization ◽  
Offshore Wind ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Local Flow

Abstract The offshore wind industry is undergoing a rapid development due to its advantage over the onshore wind farm. The vertical axis wind turbine (VAWT) is deemed to be potential in offshore wind energy utilization. A design of the offshore vertical axis wind turbine with a deflector is proposed and studied in this paper. Two-dimensional computational fluid dynamics (CFD) simulation is employed to investigate the aerodynamic performance of wind turbine. An effective method of obtaining the blade’s angle of attack (AoA) is introduced in CFD simulation to help analyze the blade aerodynamic torque variation. The numerical simulations are validated against the measured torque and wake velocity, and the results show a good agreement with the experiment. It is found that the blade instantaneous torque is correlated with the local AoA. Among the three deflector configurations, the front deflector leads to favorable local flow for the blade, which is responsible for the improved performance.

Development of the Dual Vertical Axis Wind Turbine Using Computational Fluid Dynamics

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Gabriel Naccache ◽  
Marius Paraschivoiu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Urban Areas ◽  
High Efficiency ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Circular Path ◽  
Vertical Axis Wind Turbine

Small vertical axis wind turbines (VAWTs) are good candidates to extract energy from wind in urban areas because they are easy to install, service, and do not generate much noise; however, the efficiency of small turbines is low. Here-in a new turbine, with high efficiency, is proposed. The novel design is based on the classical H-Darrieus VAWT. VAWTs produce the highest power when the blade chord is perpendicular to the incoming wind direction. The basic idea behind the proposed turbine is to extend that said region of maximum power by having the blades continue straight instead of following a circular path. This motion can be performed if the blades turn along two axes; hence, it was named dual vertical axis wind turbine (D-VAWT). The analysis of this new turbine is done through the use of computational fluid dynamics (CFD) with two-dimensional (2D) and three-dimensional (3D) simulations. While 2D is used to validate the methodology, 3D is used to get an accurate estimate of the turbine performance. The analysis of a single blade is performed and the turbine shows that a power coefficient of 0.4 can be achieved, reaching performance levels high enough to compete with the most efficient VAWTs. The D-VAWT is still far from full optimization, but the analysis presented here shows the hidden potential and serves as proof of concept.

Vortex Sheet Analysis of the Giromill

1978 ◽  
Vol 100 (3) ◽  
pp. 340-342 ◽  
Author(s):  
R. E. Wilson
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Vortex Sheet ◽  
Maximum Energy ◽  
Power Coefficient ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Wind Force ◽  
Force Coefficient ◽  
Horizontal Axis Wind Turbine

A two-dimensional analysis of the performance and flowfield of the Giromill is presented. The Giromill is a vertical-axis wind turbine with straight blades that are articulated to produce maximum energy extraction from the wind. It is found that the power coefficient and windwise force coefficient for the Giromill have the same limit as obtained for the horizontal-axis wind turbine. A cross-wind force is also obtained with this type of wind turbine. The cross-wind force is of second order and decreases with tip speed. Streamlines and velocity profiles are illustrated for several loading conditions.

Design and Test of a Vertical-Axis Wind Turbine with Pitch Control

2012 ◽  
Vol 225 ◽  
pp. 338-343 ◽  
Author(s):  
J.J. Miau ◽  
S.Y. Liang ◽  
R.M. Yu ◽  
C.C. Hu ◽  
T.S. Leu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Variable Pitch ◽  
Pitch Control ◽  
Remarkable Improvement ◽  
The One ◽  
Variable Pitch Control ◽  
Starting Torque

The concept of pitch control has been implemented in the design of a small vertical-axis wind turbine. Benefits gained can be shown by the experimental and numerical results presented in this paper. As found, the method of variable pitch control outperforms the one of fixed pitch control. The present results show that the former can make remarkable improvement on the starting torque as well as the aerodynamic characteristics at low tip speed ratios.

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