Leading-edge energy transfer governs flutter onset of a pitching finite wing in low-Reynolds number flows
Abstract
Flutter onset is determined by the sign of the aerodynamic work on the structure, but cycle-integrated work does not reveal where this energy transfer originates. We perform direct numerical simulations of incompressible flow over an aspect-ratio-two NACA 0015 wing pitching at Re=1000 and use lobe-resolved force-moment partitioning to identify the vortical contributions to aeroelastic power. The net energy transfer changes sign near U*=4.25. Across this transition, the upper leading-edge contribution changes from damping at U*=2 to excitation near onset and becomes the largest positive contribution at U*=6. Near the stability boundary, positive leading-edge work is nearly balanced by negative trailing-edge work. This change is accompanied by a reorganization of the leading-edge pressure footprint and a reduction in the phase difference between aerodynamic moment and pitch rate, linking flutter onset to the timing of the leading-edge vortex system. A single slowly growing-amplitude simulation recovers the finite-amplitude energy boundary, while a free-pitching calculation confirms the predicted instability. As the motion approaches its limit cycle, the energy pathways redistribute, and a response-frequency-matched forced calculation reproduces the large-amplitude energy budget. These results distinguish the mechanism that triggers flutter from that which saturates the response and identify the leading edge as a natural target for flutter suppression.
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BibTeX
@misc{parvathgari2026leadingedge,
title = {{Leading-edge energy transfer governs flutter onset of a pitching finite wing in low-Reynolds number flows}},
author = {Apoorva R. Parvathgari and Tulsi Ram Sahu and Aditya G. Nair},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.02402},
eprint = {2610.02402},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.02402},
}
RIS
TY - UNPB
TI - Leading-edge energy transfer governs flutter onset of a pitching finite wing in low-Reynolds number flows
AU - Apoorva R. Parvathgari
AU - Tulsi Ram Sahu
AU - Aditya G. Nair
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.02402
UR - https://arxiv.org/abs/2610.02402
AB - Flutter onset is determined by the sign of the aerodynamic work on the structure, but cycle-integrated work does not reveal where this energy transfer originates. We perform direct numerical simulations of incompressible flow over an aspect-ratio-two NACA 0015 wing pitching at Re=1000 and use lobe-resolved force-moment partitioning to identify the vortical contributions to aeroelastic power. The net energy transfer changes sign near U^*=4.25. Across this transition, the upper leading-edge contribution changes from damping at U^*=2 to excitation near onset and becomes the largest positive contribution at U^*=6. Near the stability boundary, positive leading-edge work is nearly balanced by negative trailing-edge work. This change is accompanied by a reorganization of the leading-edge pressure footprint and a reduction in the phase difference between aerodynamic moment and pitch rate, linking flutter onset to the timing of the leading-edge vortex system. A single slowly growing-amplitude simulation recovers the finite-amplitude energy boundary, while a free-pitching calculation confirms the predicted instability. As the motion approaches its limit cycle, the energy pathways redistribute, and a response-frequency-matched forced calculation reproduces the large-amplitude energy budget. These results distinguish the mechanism that triggers flutter from that which saturates the response and identify the leading edge as a natural target for flutter suppression.
ER -