Open AccessWind tunnel test on airfoil Risø‐B1‐18 with an Active Trailing Edge Flap
Author(s) -
Bak Christian,
Gaunaa Mac,
Andersen Peter B.,
Buhl Thomas,
Hansen Per,
Clemmensen Kasper
Publication year - 2009
Publication title -
wind energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.743
H-Index - 92
eISSN - 1099-1824
pISSN - 1095-4244
DOI - 10.1002/we.369
Subject(s) - airfoil , trailing edge , aerodynamic center , wind tunnel , lift (data mining) , chord (peer to peer) , leading edge , lift coefficient , mechanics , engineering , physics , structural engineering , aerodynamics , acoustics , angle of attack , pitching moment , computer science , reynolds number , distributed computing , turbulence , data mining
A wind tunnel test of the wind turbine airfoil Risø‐B1‐18 equipped with an Active Trailing Edge Flap (ATEF) was carried out. The ATEF was 9% of the total chord, made of piezo electric actuators attached to the trailing edge of a non‐deformable airfoil and actuated using an (electric) amplifier. The airfoil was tested at Re = 1.66 × 10 6 . Steady state and dynamic tests were carried out with prescribed deflections of the ATEF. The steady state tests showed that deflecting the ATEF towards the pressure side (positive β) translated the lift curve to higher lift values and deflecting the ATEF towards the suction side (negative β) translated the lift curve to lower lift values. Testing the airfoil for a step change of the ATEF from β = −3.0 to +1.8 showed that the obtainable Δ c l was 0.10 to 0.13 in the linear part of the lift curve. Modeling the step response with an indicial function formulation showed that the time constant in the step change and in sinusoidal deflections in dimensionless terms was T0 * = 0.6. Testing the ability of the ATEF to cancel out the load variations for an airfoil in sinusoidal pitch motion of Δ AOA = ±0.7 showed that it was possible to reduce the amplitude with around 80% from Δ c l = 0.148 to Δ c l = 0.032. Copyright © 2009 John Wiley & Sons, Ltd.