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arXiv · 2506.00306

Phase-based analysis and control of low Reynolds number aeroelastic flows

Chathura R. Sumanasiri·Tulsi Ram Sahu·Aditya G. Nair
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Abstract

Flutter in lightweight airfoils under unsteady flows presents a critical challenge in aeroelastic stability and control. This study uncovers phase-localized mechanisms that drive the onset and suppression of flutter in a freely pitching airfoil at low Reynolds number. By introducing targeted impulsive stiffness perturbations, we identify critical phases that trigger instability. Using phase-sensitivity functions, energy-transfer metrics, and dynamic mode decomposition, we show that flutter arises from phase lock-on between structural and fluid modes. Leveraging this insight, we design an energy-optimal, phase-based control strategy that applies transient heaving motions to disrupt synchronization and arrest unstable growth. This minimal, time-localized control suppresses subharmonic amplification and restores stable periodic motion.

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Chathura R. Sumanasiri, Tulsi Ram Sahu, Aditya G. Nair. 2025-05-30. Phase-based analysis and control of low Reynolds number aeroelastic flows. https://doi.org/10.1017/jfm.2025.10721

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