City Research Online

Abstract

Flexible wingtip extensions attached to the end of a symmetric (NACA 0012) aerofoil have been tested at 0°, 5°, 10° angles of attack and speeds of 20 cm s−1, 30 cm s−1, 40 cm s−1. Time resolved particle image velocimetry (TR-PIV) was used to compare a clean wing and a wing with flexible wingtip extensions. Material testing of the extensions were also conducted to ensure comparable flow conditions between that of bird flight and the tests. As anticipated for the clean wing, a large roll-up motion was observed which resulted in a large wingtip vortex. However when the flexible extensions were attached, it has been shown that the main tip vortex is dislocated and separated into smaller vortices off of each tip. It is concluded that the flexible extensions are able to replicate a bird’s slotted wingtip and modify the vortex sheet to reduce induced drag.

Publication Type:	Conference or Workshop Item (Paper)
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TL Motor vehicles. Aeronautics. Astronautics
Departments:	School of Science & Technology > Engineering

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