Study of Sinusoidal Perturbations on the Leading Edge of an Aircraft Wing *

The application of leading edge sinusoidal tubercles applied on an aircraft wing is believed to improve the aerodynamic performance in terms of lift and drag as well as the stall characteristics of the wing. A NACA 2421 airfoil model was selected to mimic the whale flippers with the tubercle configuration on the leading edge of a tapered wing of 0.5 taper ratio, as it achieved better aerodynamic performance in comparison to 1.0, 0.7, and 0.3 taper ratios. The analysis was conducted at Mach 0.2 for low-speed aircraft with varying tubercle locations across the wingspan; full, half and quarter span. The results obtained showed how the tubercle configurations located across the full span of A2W30 attained. Particularly, 5.42% more lift produced than the unmodified wing at the stalling AOA, while the lift coefficient of the A8W30 Quarter Span model in the post-stall regime dropped by 14.68% in contrast to the unmodified wing that experienced a 22.58% drop in lift coefficient. The modified wing with tubercles experienced enhanced performance at the optimum Re of 1,000,000 and additionally, it showed how tubercles helped in reducing the acoustic power levels which could contribute to a minimal loss of aircraft energy in terms of sound energy.