Experimental investigation of a pitch-oscillating wind turbine airfoil with vortex generators

2020 ◽  
Vol 12 (6) ◽  
pp. 063304
Author(s):  
Shuang Li ◽  
Lei Zhang ◽  
Jin Xu ◽  
Ke Yang ◽  
Juanjuan Song ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Wind Turbine ◽  
Vortex Generators ◽  
Wind Turbine Airfoil

scholarly journals Controlling dynamic stall using vortex generators on a wind turbine airfoil

2021 ◽  
Author(s):  
D. De Tavernier ◽  
C. Ferreira ◽  
A. Viré ◽  
B. LeBlanc ◽  
S. Bernardy
Keyword(s):  
Wind Turbine ◽  
Vortex Generators ◽  
Dynamic Stall ◽  
Wind Turbine Airfoil

scholarly journals Effect of Single-Row and Double-Row Passive Vortex Generators on the Deep Dynamic Stall of a Wind Turbine Airfoil

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2535
Author(s):  
Chengyong Zhu ◽  
Tongguang Wang ◽  
Jie Chen ◽  
Wei Zhong
Keyword(s):  
Wind Turbine ◽  
Flow Separation ◽  
Aerodynamic Performance ◽  
Vortex Generators ◽  
Dynamic Stall ◽  
Aerodynamic Forces ◽  
Double Row ◽  
Single Row ◽  
Maximum Angle ◽  
Wind Turbine Airfoil

Passive vortex generators (VGs) have been widely applied on wind turbines to boost the aerodynamic performance. Although VGs can delay the onset of static stall, the effect of VGs on dynamic stall is still incompletely understood. Therefore, this paper aims at investigating the deep dynamic stall of NREL S809 airfoil controlled by single-row and double-row VGs. The URANS method with VGs fully resolved is used to simulate the unsteady airfoil flow. Firstly, both single-row and double-row VGs effectively suppress the flow separation and reduce the fluctuations in aerodynamic forces when the airfoil pitches up. The maximum lift coefficient is therefore increased beyond 40%, and the onset of deep dynamic stall is also delayed. This suggests that deep dynamic-stall behaviors can be properly controlled by VGs. Secondly, there is a great difference in aerodynamic performance between single-row and double-row VGs when the airfoil pitches down. Single-row VGs severely reduce the aerodynamic pitch damping by 64%, thereby undermining the torsional aeroelastic stability of airfoil. Double-row VGs quickly restore the decreased aerodynamic efficiency near the maximum angle of attack, and also significantly accelerate the flow reattachment. The second-row VGs can help the near-wall flow to withstand the adverse pressure gradient and then suppress the trailing-edge flow separation, particularly during the downstroke process. Generally, double-row VGs are better than single-row VGs concerning controlling deep dynamic stall. This work also gives a performance assessment of VGs in controlling the highly unsteady aerodynamic forces of a wind turbine airfoil.

scholarly journals Numerical Investigation of Passive Vortex Generators on a Wind Turbine Airfoil Undergoing Pitch Oscillations

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 654 ◽  
Author(s):  
Chengyong Zhu ◽  
Tongguang Wang ◽  
Jianghai Wu
Keyword(s):  
Wind Turbine ◽  
Stokes Equations ◽  
Turbine Blades ◽  
Operating Conditions ◽  
Vortex Generators ◽  
Dynamic Stall ◽  
Wind Turbine Blades ◽  
Unsteady Aerodynamic ◽  
Wind Turbine Airfoil ◽  
Airfoil Flow

Passive vortex generators (VGs) are widely used to suppress the flow separation of wind turbine blades, and hence, to improve rotor performance. VGs have been extensively investigated on stationary airfoils; however, their influence on unsteady airfoil flow remains unclear. Thus, we evaluated the unsteady aerodynamic responses of the DU-97-W300 airfoil with and without VGs undergoing pitch oscillations, which is a typical motion of the turbine unsteady operating conditions. The airfoil flow is simulated by numerically solving the unsteady Reynolds-averaged Navier-Stokes equations with fully resolved VGs. Numerical modelling is validated by good agreement between the calculated and experimental data with respect to the unsteady-uncontrolled flow under pitch oscillations, and the steady-controlled flow with VGs. The dynamic stall of the airfoil was found to be effectively suppressed by VGs. The lift hysteresis intensity is greatly decreased, i.e., by 72.7%, at moderate unsteadiness, and its sensitivity to the reduced frequency is favorably reduced. The influences of vane height and chordwise installation are investigated on the unsteady aerodynamic responses as well. In a no-stall flow regime, decreasing vane height and positioning VGs further downstream can lead to relatively high effectiveness. Compared with the baseline VG geometry, the smaller VGs can decrease the decay exponent of nondimensionalized peak vorticity by almost 0.02, and installation further downstream can increase the aerodynamic pitch damping by 0.0278. The obtained results are helpful to understand the dynamic stall control by means of conventional VGs and to develop more effective VG designs for both steady and unsteady wind turbine airfoil flow.

Characterization of Vortex Generators Induced Flow around Wind Turbine Airfoil

2013 ◽  
Vol 448-453 ◽  
pp. 1779-1784 ◽  
Author(s):  
Li Ping Dai ◽  
Hui Zhang ◽  
Jian Dong Jiao ◽  
Xin Kai Li ◽  
Shun Kang
Keyword(s):  
Wind Turbine ◽  
Flow Separation ◽  
Lift Coefficient ◽  
Vortex Generator ◽  
Control Flow ◽  
Vortex Generators ◽  
Different Types ◽  
Wind Turbine Airfoil ◽  
Induced Flow

Vortex generators (VGs) are an effective way to control flow separation in wind turbine. To understand the mechanism of VGs controlling flow separation, the flow field around airfoil Du97W300 with VGs was simulated and analyzed with CFD tools, and this numerical method is validated through the comparison between the numerical results and the experimental results. Furthermore, the flow fields around airfoil equipped with four different types of VGs are calculated and analyzed. The results show that the helical vortex induced by counter-rotating VGs develop approximately along streamwise direction; these types of VGs can cause a delay in stall and enhance the maximum airfoil lift coefficient. However the helical induced vortex actuated by the co-rotating VGs develop nearly along vortex generator direction and cannot cause a delay in stall effectively. In the counter-rotating VGs, the Q integration (the character parameter of induced vortex) of rectangular is twice of the triangle, and the Q integration of the forward triangle is almost equal to the backward triangle VGs.

Flow control on the NREL S809 wind turbine airfoil using vortex generators

Energy ◽  
2017 ◽  
Vol 118 ◽  
pp. 1210-1221 ◽  
Author(s):  
Haipeng Wang ◽  
Bo Zhang ◽  
Qinggang Qiu ◽  
Xiang Xu
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Vortex Generators ◽  
Wind Turbine Airfoil

Dynamic stall control of the wind turbine airfoil via single-row and double-row passive vortex generators

Energy ◽  
2019 ◽  
Vol 189 ◽  
pp. 116272 ◽  
Author(s):  
Chengyong Zhu ◽  
Jie Chen ◽  
Jianghai Wu ◽  
Tongguang Wang
Keyword(s):  
Wind Turbine ◽  
Vortex Generators ◽  
Dynamic Stall ◽  
Double Row ◽  
Single Row ◽  
Wind Turbine Airfoil ◽  
Stall Control
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