Wing Design Day 8
Updated: Mar 26, 2020
Hoerner wingtips reduce the size of the wingtip vortices and therefore decrease lift induced drag which can account for 50% of the total drag at cruise and even more during takeoff and landing. Hoerner wingtips are proven to to increase the cruise speed 2-4mph, increase climb rate 75-100ft/min, improve roll stability, decrease stall speed 4-5mph, and decrease takeoff distance. Based on Dr. Hoerner’s 6 primary wingtip design requirements, Design Team successfully implemented 5 of them into a draft of some Hoerner wingtips. Design team struggled to create the convex curve along the bottom plane but will continue to search for a workaround in the future. Since the Hoerner wingtip is a very organic curve, the current plan is to slice it into 10ish layers and then CNC mill each one of them out of house insulation foam before gluing them all together and (lightly) fiberglassing the final product. This assembly will then be bolted or epoxied to the wing tip rib. To make the Hoerner wingtip removable, a thin 1/16” plywood “wingtip cap” plate was also added, and serves as a blunt wingtip (protecting the ends of the spars and stringers) and a Hoerner wingtip attachment point.
*Editors note: the thought processes and design choices presented in this article don't necessarily represent those implemented into the final design and are subject to change. Flight Club Aerospace is a group of amateur students with no formal education in any fields of engineering. We present this information for educational purposes only, with the understanding that it is not to be re-created without adequate professional oversight and mentorship. For our latest designs and updates, please see our most recent blog posts.