Winglet Design and Optimization for Uavs

Abstract

Winglets have been shown to improve the efficiency of large aircraft at high subsonic speeds, but winglet designs for smaller aircraft like UAVs are unproven. Winglets improve efficiency by diffusing the shed wingtip vortex, which in turn reduces the drag due to lift and improves the wing's lift over drag ratio. This research investigates methods for designing and optimizing winglet geometry for UAVs that operate at Reynolds numbers near 10^6. The design methodology is based on the vortex lattice method. Optimized designs are tested and compared with base designs for validation and include both Whitcomb and blended winglets. Designs are validated using wind tunnel tests. The resulting methodology is then applied to existing UAV platforms for specific performance improvements.