EFFECT OF ROTATING CYLINDER ON BOUNDARY LAYER BEHAVIOR AND AERODYNAMIC PERFORMANCE OF NACA 0015 AIRFOIL

Flow separation over airfoils at moderate and high angles of attack leads to a significant degradation in aerodynamic performance. Active boundary layer control using moving surfaces provides an effective approach to delay separation and enhance lift. In this study, the aerodynamic efficiency of a NACA 0015 airfoil equipped with a rotating leading edge cylinder is numerically investigated using computational fluid dynamics. Simulations are carried out for a range of angles of attack and cylinder surface speed ratios at low Reynolds numbers like Re = 1.2 x105. The rotating cylinder injects momentum into the boundary layer, promoting flow attachment on the upper surface and delaying stall. The results show an increase in the maximum lift coefficient of up to 45%, with the stall angle extended from approximately 12° to nearly 28°. Additionally, the lift-to-drag ratio improves significantly, with drag reductions of up to 60% at moderate angles of attack. These results demonstrate the effectiveness of rotating cylinder based moving surface boundary layer control in enhancing airfoil aerodynamic efficiency.