Controlling dynamic stall using vortex generators on a wind turbine airfoil

De Tavernier, D.; Ferreira, Carlos; Viré, A.C.; LeBlanc, B.P.; Bernardy, S.

doi:10.1016/j.renene.2021.03.019

Controlling dynamic stall using vortex generators on a wind turbine airfoil

Title

Controlling dynamic stall using vortex generators on a wind turbine airfoil

Author

De Tavernier, D. (TU Delft Wind Energy)
Ferreira, Carlos (TU Delft Wind Energy)
Viré, A.C. (TU Delft Wind Energy)
LeBlanc, B.P. (TU Delft Wind Energy)
Bernardy, S. (TU Delft Facility Aerodynamics Laboratory)

Date

2021

Abstract

Vortex generators (VGs) have proven their capabilities in wind turbine applications to delay stall in steady flow conditions. However, their behaviour in unsteady conditions is insufficiently understood. This paper presents an experimental study that demonstrates the effect of VGs in unsteady flow, including controlling and suppressing the dynamic stall process. An airfoil, particularly designed for a vertical-axis wind turbine, has been tested in a wind tunnel in steady flow and unsteady flow caused by a sinusoidal pitching motion. The steady and unsteady pressure distributions, lift, drag and moment were measured for a range of cases. The cases vary in motion (mean angle of attack, frequency, amplitude) and VG configuration. VGs have shown to delay or even suppress dynamic stall depending on the VG configuration, with particularly important factors being VG height and VG mounting position. The VGs promote a later dynamic stall onset and reduce the hysteresis loop. As soon as the VG's effectiveness vanishes, the configurations with VGs show a severe loss in normal coefficient, larger than in the case of the clear airfoil. However, the flow reattaches quicker and the airfoil recovers easier from the deep-stall conditions. The experimental results demonstrate that the use of VGs significantly changes the unsteady aerodynamic loads. This experimental database can serve for validation purposes to evaluate whether current modelling strategies in unsteady conditions are sufficient for blades equipped with VGs.

Subject

Dynamic stall
Experiment
Vertical-axis wind turbines
Vortex generators
Wind turbines

To reference this document use:

http://resolver.tudelft.nl/uuid:95af29fc-6a7c-4a0f-8425-7d425ffb0feb

DOI

https://doi.org/10.1016/j.renene.2021.03.019

ISSN

0960-1481

Source

Renewable Energy, 172, 1194-1211

Part of collection

Institutional Repository