Active control of flow separation and structural vibrations of wind turbine blades

Wind Energy ◽  
2010 ◽  
Vol 13 (2-3) ◽  
pp. 221-237 ◽  
Author(s):  
Victor Maldonado ◽  
John Farnsworth ◽  
William Gressick ◽  
Michael Amitay
Keyword(s):  
Wind Turbine ◽  
Active Control ◽  
Flow Separation ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Structural Vibrations ◽  
Control Of Flow

scholarly journals A NEW ACTIVE CONTROL STRATEGY FOR WIND-TURBINE BLADES UNDER OFF-DESIGN CONDITIONS

2012 ◽  
Vol 19 ◽  
pp. 283-292 ◽  
Author(s):  
RI-KUI ZHANG ◽  
JIE-ZHI WU ◽  
SHI-YI CHEN
Keyword(s):  
Wind Turbine ◽  
Active Control ◽  
Turbine Blades ◽  
Leading Edge ◽  
Operating Conditions ◽  
Wind Turbine Blades ◽  
Delta Wings ◽  
Control Units ◽  
Shaft Torque ◽  
Active Control Strategy

A new active control strategy for wind-turbine blades under off-design conditions has been investigated in this paper. According to our previous work, in comparison with the traditional straight leading-edge blade, a new kind of bionic blades with a sinusoidal leading edge can significantly enhance the turbine's power output at high speed inflows. However, the wavy leading-edge shape is unfavorable under the design operating conditions since an early boundary-layer separation is inevitable for a wind-turbine blade because of the geometric disturbances of the leading-edge tubercles. But for the present active control, the deflect in wavy leading-edge blades can be eliminated by introducing a series of small flat delta wings as the control units, since delta wings can also generate powerful leading-edge vortices. As a preliminary test, our numerical results show that, the shaft-torque fluctuation in the turbine's stall region can be improved from 27.8% for a straight leading-edge blade (no control) to 8.9% for the present active control; and by adjusting the control parameters, the control units nearly have not any negative effect on the blade's shaft torque under the design conditions. We believe that, as an auxiliary tool of the conventional control strategies, the present active control approach may be favorable to generate a more stable and more controllable power output for wind turbines under all operating conditions (even in the yawed inflows).

Investigate aerodynamic performance of wind turbine blades with vortex generators at the transition area

2021 ◽  
pp. 0309524X2110385
Author(s):  
Zhou Wu ◽  
Tao Chen ◽  
Haipeng Wang ◽  
Hongwei Shi ◽  
Mingzhou Li
Keyword(s):  
Wind Turbine ◽  
Flow Separation ◽  
Turbine Blades ◽  
Simulation Method ◽  
High Energy ◽  
Aerodynamic Performance ◽  
Vortex Generators ◽  
Geometrical Parameters ◽  
Wind Turbine Blades ◽  
Transition Area

The transition area of the blade had a large relative thickness of airfoil, which was prone to the flow separation. The vortex generators (VGs) could restrain the flow separation. In this paper, the VGs were installed at the transition area of the WindPACT 1.5 MW wind turbine blades. The numerical simulation method was used to investigate the effects of the VGs on the aerodynamic performance of the blade. The high-energy vortexes were generated at the tail by the VG. It could change the energy distribution and flow characteristics of the airflow in the boundary layer. There were influences by the geometric parameters of the VGs. The VGs could change the aerodynamic performance at the transition area of the blade. A satisfactory result was obtained for reasonable geometrical parameters of the VGs. It also could restrain the flow separation of the blade surface and improve the torque.

Wind-tunnel Force-measurements of Gurney Flaps for Active Control of Wind Turbine Blades

2022 ◽  
Author(s):  
Wasi U. Ahmed ◽  
Keshav Panthi ◽  
Giacomo Valerio Iungo ◽  
D. Todd Griffith ◽  
Mario Rotea ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Active Control ◽  
Turbine Blades ◽  
Force Measurements ◽  
Wind Turbine Blades ◽  
Gurney Flaps

Investigation of Wind Turbine Blades with Tubercles

2014 ◽  
Vol 1051 ◽  
pp. 832-839 ◽  
Author(s):  
Kelvin Leung
Keyword(s):  
Flow Visualization ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Flow Separation ◽  
Power Output ◽  
Turbine Blades ◽  
Length Ratio ◽  
Wind Turbine Blades

This paper describes the testing of wind turbine blades with tubercles in two different ways: outdoor testing and flow visualization. In the outdoor testing, the tubercle pitch was varied for turbine blade lengths of 30 cm, 40 cm, and 50 cm. The pitch-to-length ratio of approximately 1/10 to 1/16 produced the most power output. In flow visualization, both tubercle pitch and amplitude were varied. Vortices created behind the tubercles were shown to increase lift by minimizing flow separation.

Flow Analysis of Straight and Swept Edge Wind Turbine Blades in Blade and Wake Regions

2012 ◽  
Author(s):  
Ryoichi S. Amano ◽  
Pradeep Mohan Mohan Das ◽  
Mohammed Alnakhli
Keyword(s):  
Wind Turbine ◽  
Cross Section ◽  
Flow Separation ◽  
Turbine Blades ◽  
Flow Analysis ◽  
Rotor Blades ◽  
Straight Edge ◽  
Wind Turbine Blades ◽  
Horizontal Axis Wind Turbine ◽  
High Reynolds

This paper presents the comparison of the wake sizes and shapes between two different designs of a horizontal axis wind turbine (HAWT) rotor blades; one a straight edged and the other with a backward sweep. The straight edge blade was constructed so that it is optimal for on coming wind and rotation speeds with 7m/s and 23rpm. The blade has a length of 20m and uses a constant airfoil cross section. The swept edge blade has the same characteristics as the straight edge except for the trajectory of the edge. Each swept blade has the same cross section with the same dimensions at the same distance from the hub as its corresponding section in the straight edge blade. The analysis was done at a range of velocities from 7 m/s to 18 m/s. It was confirmed that the stall region observed by previous studies is in fact due to the flow separation throughout the span of the blade for both the straight and swept blades. A comparison of wake lengths for both straight and swept blades was done for a range of wind velocities. It was shown that the wake length for swept edged blades were longer than for straight blades and both start decreasing beyond the stall region. From a comparison of flow separation angles from experiments and CFD computations, both were observed to follow the same trends at high Reynolds numbers.

Experiments of Wind Turbine Blades with Rocket Triggered Lightning

2009 ◽  
Vol 129 (5) ◽  
pp. 689-695
Author(s):  
Masayuki Minowa ◽  
Shinichi Sumi ◽  
Masayasu Minami ◽  
Kenji Horii
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Triggered Lightning
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