Experimental study of the aerodynamics of micro airfoils with wavy surface and the use of different patterns inspired by nature

Enhancing the aerodynamic performance of airfoils, minimizing drag, and controlling flow separation are key objectives in aerospace research, pursued through various methods. A miniature wind tunnel with a test section of 100 × 100 mm was designed and constructed for this study to enable experimental testing of low-volume models at low Reynolds numbers. Given the increasing application of small-scale flying devices and the limited research available at low Reynolds numbers, this study experimentally investigates the aerodynamic behavior of a micro-scale airfoil. Specifically, the influence of surface corrugation on the aerodynamic performance of a NACA 0012 airfoil was examined. For validation, a standard NACA 0012 airfoil was fabricated and tested in the wind tunnel, followed by a corrugated version with wavy contours on the leading edge, trailing edge, upper surface, and lower surface. At Reynolds numbers of 15,000 and 66,000, the corrugated airfoil exhibited superior aerodynamic performance compared to the baseline configuration. At Re = 15,000 and an angle of attack of 15°, the lift coefficient (Cl) increased from 0.22 for the standard airfoil to 0.33 for the corrugated design, representing a ~50% improvement. At Re = 66,000, the drag coefficient (Cd) beyond the 15° angle of attack increased from 0.57 in the standard airfoil to 0.61 in the corrugated one, indicating a growth of over 7%. Below the critical angle of attack, the corrugated airfoil demonstrated higher lift and lower drag than the standard NACA 0012 airfoil, resulting in significantly improved aerodynamic efficiency beyond the critical point