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

Experimental investigations of flow over NACA airfoils 0021 and 4412 of wind turbine blades with and without Tubercles

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Critical Region ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Wind Turbine Blades

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.

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).

Wind Tunnel Experimental Study of Wind Turbine Airfoil Aerodynamic Characteristics

2012 ◽  
Vol 260-261 ◽  
pp. 125-129
Author(s):  
Xin Zi Tang ◽  
Xu Zhang ◽  
Rui Tao Peng ◽  
Xiong Wei Liu
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Aerodynamic Characteristics ◽  
Wind Turbine Blades ◽  
High Lift ◽  
Minimum Drag ◽  
Stall Angle ◽  
High Reynolds

High lift and low drag are desirable for wind turbine blade airfoils. The performance of a high lift airfoil at high Reynolds number (Re) for large wind turbine blades is different from that at low Re number for small wind turbine blades. This paper investigates the performance of a high lift airfoil DU93-W-210 at high Re number in low Re number flows through wind tunnel testing. A series of low speed wind tunnel tests were conducted in a subsonic low turbulence closed return wind tunnel at the Re number from 2×105to 5×105. The results show that the maximum lift, minimum drag and stall angle differ at different Re numbers. Prior to the onset of stall, the lift coefficient increases linearly and the slope of the lift coefficient curve is larger at a higher Re number, the drag coefficient goes up gradually as angle of attack increases for these low Re numbers, meanwhile the stall angle moves from 14° to 12° while the Re number changes from 2×105to 5×105.

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

A New Vascular System Highly Efficient in the Storage and Transport of Healing Agent for Self-Healing Wind Turbine Blades

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Rulin Shen ◽  
Ryoichi S. Amano ◽  
Giovanni Lewinski ◽  
Arun Kumar Koralagundi Matt
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Vascular System ◽  
Copper Wire ◽  
Turbine Blades ◽  
Real Life ◽  
Transport Processes ◽  
Self Healing ◽  
Wind Turbine Blades ◽  
Healing Agent

Self-healing wind turbine blades offer a substantial offset for costly blade repairs and failures. We discuss the efforts made to optimize the self-healing properties of wind turbine blades and provide a new system to maximize this offset. Copper wire coated by paraffin wax was embedded into fiber-reinforced polymer (FRP) samples incorporated with Grubbs' first-generation catalyst. The wires were extracted from cured samples to create cavities that were then injected with the healing agent, dicyclopentadiene (DCPD). Upon sample failure, the DCPD and catalyst react to form a thermosetting polymer to heal any crack propagation. Three-point bending flexural tests were performed to obtain the maximum flexural strengths of the FRP samples before and after recovery. Using those results, a hierarchy of various vascular network configurations was derived. To evaluate the healing system's effect in a real-life application, a prototype wind turbine was fabricated and wind tunnel testing was conducted. Using ultraviolet (UV) dye, storage and transport processes of the healing agent were observed. After 24 h of curing time, Raman spectroscopy was performed. The UV dye showed dispersion into the failure zone, and the Raman spectra showed the DCPD was polymerized to polydicyclopentadiene (PDCPD). Both the flexural and wind tunnel test samples were able to heal successfully, proving the validity of the process.

PERFORMANCE EVALUATION AND WAKE STUDY OF A MICRO WIND TURBINE

2011 ◽  
Vol 35 (1) ◽  
pp. 101-117 ◽  
Author(s):  
Graeme I. Comyn ◽  
David S. Nobes ◽  
Brian A. Fleck
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Power Output ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Published Data ◽  
Wind Turbine Blades ◽  
Axial Thrust ◽  
Cross Sectional ◽  
Output Performance

In preparation for a study on icing of wind turbine blades, we tested a horizontal axis micro wind turbine in a low speed wind tunnel. The ratio of wind turbine rotor area to wind tunnel cross-sectional area resulted in highly blocked experimental configuration. The turbine was instrumented to measure rotational speed of the rotor, axial thrust and power output. Performance characteristics were calculated and compared with the manufacturer’s published data. In addition, the near wake of the turbine was measured with a Kiel probe. One dimensional axial momentum theory, including a modification that includes channel walls, was applied to determine power extracted from the wind by the rotor. The results were compared to actual power output and show that though the assumptions of the model over-predict power by 50 % the basic trend is followed.

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