Mid-Fidelity Approaches for the Non-Linear Aeroelastic Assessment of The Pazy Wing

Predicting the non-linear aeroelastic behavior of very flexible structures and the limit cycle oscillations that often develop is a challenge. This work investigates the nonlinear aeroelastic behavior of the Pazy Wing to determine the nature of its LCOs by coupling a nonlinear structural beam model with different mid-fidelity aerodynamic methods: the vortex lattice method and the panel method. The results demonstrate that the limit cycle originates from nonlinear structural effects, rather than aerodynamic nonlinearities. While both methods successfully predict the onset of the phenomenon, this study highlights that only the panel method accurately estimates the oscillation amplitude when compared to experimental data. This underscores the fundamental role of 3D aerodynamic effects, which are underestimated by the vortex lattice. The study therefore provides clear guidance for selecting efficient models, recommending the coupling of a nonlinear structural model with 3D aerodynamics as the optimal approach for a correct assessment of LCO severity.