Flutter Suppression Enhancement in Coupled Nonlinear Airfoils with Intermittent Mixed Interactions

TL;DR

This paper introduces an intermittent mixed coupling strategy to enlarge the amplitude death regime, thereby enhancing flutter suppression in coupled nonlinear airfoils, which is crucial for aircraft structural safety.

Contribution

It proposes a novel intermittent mixed coupling approach combining instantaneous and time-delayed interactions to improve flutter suppression in nonlinear coupled airfoils.

Findings

Intermittent mixed coupling enlarges amplitude death regions.

Continuous mixed coupling promotes broader AD onset.

Intermittent interactions further enhance flutter suppression.

Abstract

Flutter suppression facilitates the improvement of structural reliability to ensure the flight safety of an aircraft. In this study, we propose a novel strategy for enlarging amplitude death (AD) regime to enhance flutter suppression in two coupled identical airfoils with structural nonlinearity. Specifically, we introduce an intermittent mixed coupling strategy, i.e., a linear combination of intermittent instantaneous coupling and intermittent time-delayed coupling between two airfoils. Numerical simulations are performed to reveal the influence mechanisms of different coupling scenarios on the dynamical behaviors of the coupled airfoil systems. The obtained results indicate that the coupled airfoil systems experience the expected AD behaviors within a certain range of the coupling strength and time-delayed parameters. The continuous mixed coupling favors the onset of AD over a larger parameter set of coupling strength than the continuous purely time-delayed coupling. Moreover, the presence of intermittent interactions can lead to a further enlargement of the AD regions, that is, flutter suppression enhancement. Our findings support the structural design and optimization of an aircraft wing for mitigating the unwanted aeroelastic instability behaviors.