Effect of Reduced Frequency on the Flow Pattern of Pitch Oscillating Elliptic Airfoil |
Ki-Young Lee, Hyong-Seok Chung, Myong-Hwan Sohn |
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피치 진동하는 타원형 에어포일의 환산주파수가 날개 주위 유동패턴에 미치는 영향 |
이기영, 정형석, 손명환 |
1공군사관학교 기계공학과 2공군사관학교 항공우주공학과 |
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Abstract |
The purpose of this paper is to examine the dynamic stall characteristics of an elliptic airfoil when subject to constant pitch motions. In this study, which was motivated by the pressing need for a greater understanding of the reduced frequency$({kappa})$ effects on flow patterns of elliptic airfoil, the various reduced frequencies were considered. The result confirms that the reduced frequency has a profound effects on the flow patterns. The increase of ${kappa}$ accelerate the separation bubble bursting process up to ${kappa}=0.10$, then diminish with further increase in ${kappa}$. Compared with static condition, the dynamic pitching airfoil delays stall angle approximate $4{circ}{sim}5{circ}$ during pitch-up stroke for ${kappa}=0.10$. Results from this qualitative analysis provided valuable insight Into the control of dynamics stall. |
Key Words:
Pitch Oscillating Airfoil, Unsteady Flow Separation, Dynamic Stall, Reduced Frequency, Elliptic Airfoil, Particle Image Velocimetry |
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