Renewable Energy, Vol.42, 105-110, 2012
Mitigation of flow separation using DBD plasma actuators on airfoils: A tool for more efficient wind turbine operation
In this study, dielectric barrier discharge plasma actuators (DBD-PA) were used to actively control flow separation over a NACA0024 airfoil. Experiments were conducted at a free stream velocity up to U approximate to 10 m/s (Re approximate to 1.3 x 10(5)) in an open-circuit blower type wind tunnel with a test section measuring 200 mm x 200 mm x 600 mm. The airfoil model was designed specifically to incorporate minimum flow disturbances from the components of the DBD-PA and was made using rapid prototyping. A sheet of dielectric polyimide (125 mu m) with copper electrodes (35 mu m) was attached to the outer surface of the airfoil. A layer of DBD plasma across the airfoil was produced when a peak-to-peak voltage of Vp-p = 8.0 kV was applied between top and bottom electrodes at a frequency of f(p) = 9.0 kHz. This development of plasma produced a tangential air jet across the surface of the airfoil, which reached its maximum value (u(j-max)) in the range of 0.5 m/s < u(j-max) < 0.7 m/s. Varying degrees of separation flow control was observed under these conditions. Performance comparisons were made between electrodes located at the leading edge (LE) and the quarter chord (QC, 25% of chord length) at angles of attack of alpha = 8 degrees, 12 degrees, 16 degrees. The plasma-induced jet velocities and flow profiles were measured using particle image velocimetry (Ply). Characteristics such as power consumption, voltage waveform, and current magnitude were quantified through the use of a digital oscilloscope. (C) 2011 Elsevier Ltd. All rights reserved.