GEOMETRIC NONLINEAR AEROELASTIC BEHAVIOR of HIGH ASPECT RATIO WINGS

As a result of the increasing demand and performance in aircraft development, the high-aspect-ratio (HAR) wing becomes the primary structural type of the emerging aircrafts. The wing type holds high lift-to-drag ratio, large deformations and low weight inherent characteristics. Both static and dynamic aeroelastic behavior of the classic HAR wing are studied using intrinsic beam structural model coupling with finite state inflow aerodynamic model in this paper. The results show that the aeroelastic phenomenon of the flexible wing are distinctly different from traditional linear aeroelastic behavior due to the geometric nonlinear effects. It is found that the static deflect is smaller than the linear one, as well as the critical flutter velocity, which is related to the initial angle of attack. As increasing in the flow speed, the aeroelastic response of the flexible wing undergoes damping vibration, simple harmonic limit cycle oscillation (LCO) and periodic LCO phase, but no divergent behavior occurs. The analysis method is demonstrated to be capable of capturing the aeroelastic behavior of HAR wings with geometric nonlinear effects.