RESEARCH ON APPLYING FREE-FORM DEFORMATION IN AIRFOIL PARAMETERIZATION AND AERODYNAMIC OPTIMIZATION
Handuo Hu, Yanping Song, Jianyang Yu, Yao Liu, Fu Chen · Proceedings · 2022
The key to an efficient parameterization method in airfoil design optimization is to control aerodynamic shape accurately with as few parameters as possible. Due to the disadvantages of traditional parameterization methods, such as plentiful variables and inflexible deformation, the Free-form Deformation (FFD) technique is getting attention. This work explores the capabilities of FFD applying in airfoil parameterization and design optimization by comparing with classical methods including B–splines and Class–Shape Transformation (CST). Firstly, a transonic airfoil RAE2822 is parameterized by three methods and their fitting errors are examined. Furthermore, numerical simulations are performed and the results are validated by comparison with experimental data. Finally, the surrogate-based optimization using Kriging model and genetic algorithm is carried out separately with each parameterization method. The results show that FFD can achieve flexible and accurate deformation with the least parameters. Moreover, the reduction of design variables accelerates convergence of optimization, thereby improving design efficiency. Among the optimized airfoils, FFD method achieves the greatest improvement on lift coefficient. Therefore, the capability of FFD method applying in aerodynamic design optimization is demonstrated.