Effect of wingtip bending morphing on gust-induced aerodynamics based on fluid-structure interaction method.

This article investigates the effects of active wingtip bending morphing on mitigating gust-induced aerodynamic loads using a fluid–structure interaction (FSI) numerical framework at a Reynolds number of 40,000. The study develops a geometrically nonlinear model for spanwise wingtip bending morphing and couples it with unsteady Reynolds-Averaged Navier–Stokes (URANS) simulations incorporating gust profiles, validated against experimental data. Results show that wingtip bending morphing can significantly reduce lift and wing root bending moment (WRBM) responses to gusts, with optimal phase offsets depending on gust ratio (GR) and flare angle; for example, at GR = 0.4 and a flare angle of 30°, lift and WRBM responses are reduced by 37% and 73%, respectively. The mitigation mechanism involves reducing the spanwise width of leading-edge vortices and low-pressure zones, with flare angle inducing a negative sectional angle of attack that enhances gust alleviation. The findings suggest that active wingtip bending morphing holds promise for gust load alleviation in future high-altitude, long-endurance unmanned aerial vehicles (HALE UAVs) and similar aircraft.