Experimental Investigation on the Performance of NACA 4412 Aerofoil with Curved Leading Edge Planform

Aircraft wings are the lifting surfaces with the chosen aerofoil sections. The efficiency as well as the performance of an aircraft mostly depends on the aerodynamic characteristics e.g. lift, drag, lift to drag ratio, etc of wings. Besides many factors, the effects of wing shape are also crucial to aircraft performance. This paper represents the experimental investigation to explore better aerodynamic performance by incorporating curvature at the leading edge of a wing. A wooden model with straight leading and trailing edge i.e. rectangular planform and another model with curved leading edge and straight trailing edge are prepared with NACA 4412 aerofoil in equal length (span) and surface area. Both the models are tested in a closed circuit wind tunnel at air speed of 85.35 kph (0.07 Mach) i.e. at Reynold's number 1.82 × 105. The static pressure at different angles of attack (-4°, 0°, 4°, 8°, 12°, 16°, 20° & 24°) are measured from both upper and lower surfaces of the wing models through different pressure tapings by using a multi-tube water manometer. From the static pressure distribution, lift coefficient, drag coefficient and lift to drag ratio of both the models are analyzed. After analyzing the data, it is found that the curved leading edge wing planform is having higher lift coefficient and lower drag coefficient than the rectangular wing planform. Thus, the curved leading edge planform is having higher lift to drag ratio than the rectangular planform.