Effect of leading edge tubercles on the aerodynamic performance of a symmetrical airfoil at subsonic flows

Reducing the wing platform area of stabilizers through innovative design offers decreased structural weight, increased aerodynamic performance, fuel efficiency, and stealth characteristics. Further, examining the characteristics of unmanned aerial vehicles at higher angles of attack is essential for enhancing their performance, adaptability, and operational effectiveness. This study mainly investigates the aerodynamic performance of wing sections with lesser wing platform areas and leading-edge tubercles compared to conventional stabilizers at higher angles of attack. Numerical simulations were performed by solving Reynolds-averaged Navier–Stokes equations with k–ω shear stress transport turbulence model using ANSYS Fluent, covering angles of attack from 0° to 26° in 2° increments and Reynolds numbers ranging from 5 × 105 to 6 × 106 assuming constant area wing section with zero swept angle along the span. The aerodynamic coefficients from numerical simulations were validated with the data obtained from a six-component external pyramidal balance attached to the low-speed wind tunnel, and they compare well. The flow field over the wing sections is examined through vorticity, turbulent kinetic energy, and coefficient of pressure plots. This study reveals that the wing with leading-edge tubercles has a higher lift coefficient and sustained the same for large angles of attack after the stall compared to a conventional stabilizer, although a slightly lesser lift is noticed till the stall. It suggests that the tubercles' wings have a promising future for vehicles that require higher lift and stability at higher angles of attack, such as aircrafts, surveillance drones, and underwater vehicles.