Study of winglets and other non-planar wing configurations for improved low-speed aerodynamic efficiency

Abstract

The induced drag is one of the most important sources of aerodynamic drag in an aircraft, and reducing it could mean saving thousands of dollars in fuel per plane and year. For this reason, since the 1970s oil crisis, agencies like NASA and airplane manufacturers have been developing wing-tip devices with the objective to reduce the induced drag. This work presents a discussion of the effects that the most common used wing-tip devices have on an airplane's aerodynamic and structural performance. It is also discussed the effects of a non-planar wing design, which is a relatively new concept design that has not been used in commercial aircrafts yet. The analysis in this work are based on inviscid flow simulations. Since induced drag only depends on the lift distribution over the wing, it can be approximated with inviscid methods and the boundary layer can be neglected.