Experimental and Numerical Nonlinear Stability Analysis of Wings Incorporating Flared Folding Wingtips

Fintan J Healy*, Ronald C M Cheung, Djamel Rezgui, Jonathan E Cooper, Thomas Wilson, Andrea Castrichini

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

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Recent studies have considered the use of wings incorporating flared folding wingtips (FFWTs) to enable higher aspect ratios (reducing overall induced drag) while also reducing gust loading and meeting airport operational requirements. This paper presents the first experimental research into the nonlinear dynamic behavior of a wing incorporating an FFWT. Wind-tunnel tests were conducted at a range of velocities below and beyond the linear flutter boundary. The experimental findings are compared with results obtained from continuation and bifurcation analyses on a representative low-fidelity numerical model. The results show that beyond the linear flutter boundary, stable limit cycle oscillations form, which is dependent on the flare angle, are bounded by either geometric or aerodynamic nonlinearities. Also presented is the effect of a wingtip trim tab on the stability boundary of a wing incorporating FFWTs. It is found that the tab angle can significantly alter the stability boundary of the system, indicating that the choice of camber is an important parameter when considering the stability boundary of FFWTs and that a moveable control surface on an FFWT could be used “in flight” to extend the stability boundary of an aircraft.
Original languageEnglish
Pages (from-to)140-154
Number of pages15
JournalJournal of Aircraft
Issue number1
Early online date4 Jul 2023
Publication statusPublished - 1 Jan 2024
Event2022 AIAA Science and Technology Forum and Exposition: AIAA SciTech Forum - San Diego, United States
Duration: 3 Jan 20227 Jan 2022

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