The Effect of Wingtip Geometry on Wake Vortex Dynamics for a Low Aspect Ratio Wing

This study investigates how wingtip geometry influences wake vortex dynamics for a low aspect ratio swept wing using a combined experimental and computational approach. The study focuses on four different wingtip devices including a flat and store tip along with a blended and split winglet. Aerodynamic wake interrogation data were acquired through a high-resolution 7-hole probe wake survey technique with very high grid densities. S-PIV and CFD simulations were also used to characterize velocity deficits, induced flow turning, vortex structure, and vortex dissipation for use in future formation flight studies. While operating the wings all under the same lift coefficient, the wingtip devices generated drastically different wake topologies. Vorticity analyses showed that winglets significantly reduce swirl intensity and they exhibit greater vortex spreading. Flow-turning metrics revealed reduced induced angles beneficial for formation flight applications on winglets versus blunt tip geometries. The research presented in this study provides a new look into nearfield vortex behavior for diverse tip devices and supports future work on formation flight performance.