Influence of Wingtip Devices in Reducing Induced Drag - A Review

Induced drag and the efforts to reduce it has been a continuous effort in the past decades. Many wingtip devices have evolved as a result of detailed research. Different winglets have reduced induced in different flight regimes. This paper documents the influence of winglets in the reduction of induced drag in the best possible way. The role of blended, raked wing grid, and spiroid winglets have been documented. It has been noted that different winglets have different efficiencies at different flight regimes and also the effect of different parameters of each winglet have been considered. The so called winglets provide an optimum reduction in drag created by the vortices at the tip of the aircraft wings. This paper also presents their theoretical significance by simultaneously keeping the aerodynamic characteristics into consideration.