Review of Winglets on Tip Vortex, Drag and Airfoil Geometry
Keywords:aircraft, induced drag, optimization, profile drag, vortex, winglets
This review is mainly based on the aerodynamic analysis and optimization of winglets, as well as the summarized induced drag (Di) and vortex detection on different types of aircraft winglets. These winglets are optimal wing tip shape changers. Each optimized winglet model has its improvement toward uncertainty under various operating regimes. The phases of winglet design and development process are discussed. Special attention is provided to the performance of winglets with the change in design aspects. Experimental and theoretical investigations are exhibited under different operating conditions to access the performance. This review highlights previous research on different types of winglets, such as blended, spiroid, multi-tip, sharklets, raked wingtips, and wing fences. This survey determines that several drag reduction techniques use optimized winglets. The effect on the reduction of Di will gradually increase the profile drag, which plays a challenge of balancing the two criteria.