Aerodynamic Performance and Vortex Structure Investigations for A NACA2412 Based Non-Slender Delta Wing

The vortex structures formed on non-slender delta wings are highly related to the sweep angle and leading-edge geometry. This study investigates the aerodynamic performance parameters of a NACA 2412-based non-slender delta wing. Aerodynamic forces, including lift and drag coefficients, were measured to determine the maximum lift-to-drag ratio. Additionally, flow structures on the suction surface and in the wake region were examined using titanium-dioxide-based surface oil visualization and the tuft-grid technique. Results indicate a maximum lift coefficient of 0.9256 at a 21° angle of attack, and a maximum lift-to-drag ratio of 5.2553 at 9°. Surface oil visualization demonstrated the movement of vortex breakdown toward the apex and highlighted unswept flow areas over the wing. Tuft-grid analysis, applied at different chord distances (1C, 2C, and 3C) from the trailing edge, revealed that the vortex cores expand and shift downward as they move downstream. In addition to the detailed observation of vortex structures and the comparison of aerodynamic forces, the results revealed that the non-slender wing exhibited a smooth stall characteristic, contrasting with the sharper stall typically observed in standard fixed-chord NACA 2412 wings.