Separation Control of NACA0015 Airfoil using Plasma Actuators

Separation control of NACA0015 airfoil using plasma actuators was investigated. Plasma actuators in span-wise array, which consists of 21 electrodes and has 1mm spacing between adjacent electrodes each having 9mm width, were located at the leading edge of the airfoil to distribute temporal periodic disturbance with phase variations φ (= 0 or π) into separation shear layer. The cord length of the airfoil was c = 100mm and corresponding Reynolds number was fixed at Re = 63,000. Non-dimensional frequency of the disturbance was chosen at F⁺ = 0.5 or 6.

Velocity fields was measured by conventional two-component PIV. Lift and drag were measured using a two-component force balance. Surface pressure was monitored by pressure transducers through pressure taps on the upper surface.

Improvements of lift coefficients were confirmed at PA actuation cases around stall angle. In addition, F⁺ = 6 cases showed greater improvements than F⁺ = 0.5. Among F⁺ = 6 cases, φ = π provided the higher lift compared to φ = 0 by approximately 1.4% at the angle of attack = 11degrees. Moreover, while quasi-spanwise-oriented roller vortices were formed at φ = 0, vortices arranged in a staggered manner were formed at φ = π. Hereafter, the relation between improvements of lift and 3D flow behavior will be clarified.