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Reductions in induced drag by the use of aft swept wing tips

Published online by Cambridge University Press:  04 July 2016

C. W. Burkett*
Affiliation:
Department of Aeronautics and AstronauticsUniversity of Southampton

Summary

Recent experimental and computational studies have indicated that rearward curvature of a wing can reduce the induced drag factor to values less than that obtained from the unswept elliptical wing considered optimal in classical wing theory. Wake non-planarity associated with a wing with aft swept tips has been suggested as a reason for this behaviour. This paper provides a systematic examination of the wake non-planarities induced by a variety of wing planforms and quantifies the induced drag reductions which may be expected. Results suggest a dependence of induced drag factor upon angle of attack, and therefore upon lift coefficient. The crescent wing is identified as the planform to derive the most benefit from its non-planar wake shape, typically a 4% reduction in induced drag factor at moderate angle of attack.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1989 

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