High-Order Harmonic Balance Vortex Lattice Method for Nonlinear Aeroelastic Limit Cycle Oscillations

This paper presents a full frequency‐domain framework for nonlinear aeroelastic analysis that couples a high‐order harmonic‐balance (HB) structural solver with a recently developed HB Vortex‐Lattice method (HB‐VLM) for unsteady aerodynamics. Embedding this coupled solver within a numerical‐continuation algorithm enables efficient tracing of self‐sustained limit‐cycle oscillations (LCOs) and their associated bifurcations without resorting to costly time‐domain integration. The approach is demonstrated on canonical three‐degree‐of‐freedom wing sections, where comparisons against time‐marching solutions confirm that high‐order HB captures rich harmonic content and bifurcation behavior. Our results highlight the method’s accuracy and robustness even in strongly nonlinear regimes, along with paving the way for rapid medium‐fidelity aeroelastic analysis of complex wings in early‐stage aircraft design.