Flow Separation Control by Flexible Memetic Coverts

This paper presents a systematic experimental investigation on a passive flow control of a NACA 0012 airfoil using memetic coverts which are installed on the suction surface. The objective of the present study is to determine the major role of memetic coverts in the aerodynamic performance of the airfoil at post-stall angles of attack. The memetic coverts width w, thickness δ, and its installation position xin are varied from 0.025c to 0.1c, 0.0002c to 0.0005c, and 0.0 to 0.05c, respectively, where xin is measured from the leading edge of the airfoil, and c is the chord length of the airfoil. In the optimum control case, the maximum lift CL,max, and lift-to-drag ratio CL/CD are enhanced as high as 30.18% (α = 18°) and 309% (α = 14°), respectively, relative to the baseline case. Furthermore, the stall angle was delayed by 6°, i.e., from 12 to 18°. By examining the flow around the airfoil, we discover the physics by which the memetic coverts improve the aerodynamic performance of the airfoil.