基于 Sobol 指数的翼型动态失速优化全局敏感性分析

Dynamic stall of an airfoil causes aerodynamic fluctuations due to the formation of leading edge stall vortices on the suction surface, which seriously affects the wind energy capture efficiency and structural stability. Aerodynamic shape optimization provides an effective method to retard the dynamic stall characteristics. However, multiple evaluations using accurate but time-consuming computational fluid dynamics (CFD) simulations make the optimization process computationally expensive. Therefore, an surrogate-based optimization (SBO) technique is proposed in this paper to reduce the computational burden. The feasibility of the framework is verified by optimizing the S809 wind turbine airfoil. Due to the increase in thickness and leading edge radius of the optimized airfoil, the development of trailing edge vortices towards the leading edge is suppressed. Compared with the baseline airfoil, the average drag coefficient and bending moment coefficient of the optimized airfoil are reduced by 48.95% and 23.74% respectively, while the lift coefficient is improved. Finally, a global sensitivity analysis of the optimized design using Sobol’s index reveals the geometric parameters and their interactions that have the greatest influence on the dynamic stall characteristics of the airfoil.