Ki-Young Lee*, Hyoung-Seog Chung** and Dong-Hyun Cho**
International Journal of Aeronautical and Space Sicences, vol. 9, no. 1, pp.111-120, 2008

Abstract : A particle image velocimetry (PIV) technique was employed to investigate the effects of blowing jet on the flow characteristics over stationary and pitch-oscillating airfoils. The Reynolds number was 7.84×105 based on the chord length. It was found that for stationary airfoil cases, continuous and pulsating blowing jets successfully reduced separated wake region at high angles of attack. A comparison study of two different types of jet blowing indicated that pulsating jet is more effective than continuous jet for flow separation control. Pulsating leading-edge blowing postpones flow separation and increased stall angle of attack by 2°～3°. For pitch-oscillating airfoil cases, the PIV results showed that blowing jet efficiently delays the separation onset point during pitch-up stroke, whereas it does not prevent flow separation during pitch-down stroke, even at angles of attack smaller than static ones.

Keyword : Pitch-Oscillating Airfoil, Flow Pattern, Blowing Jet, Flow Separation Control