Wing airfoil geometric parameterization method for efficient aerodynamic design optimization

Rodrigo F. de Souza, Ana Paula C. Cuco and Tarik H. Orra (Embraer)

CHALLENGE - Geometric parameterization is of fundamental importance for aerodynamic shape optimization. The design solution is closely related to the parametric representation of the geometry. Therefore, it must be carefully chosen in order to allow geometrical flexibility to efficiently solve optimization problems.

SOLUTION - This study aims to determine the design parameters based on a set of specified thickness, therefore we set out thickness requirements along the airfoil chord, using a method named here as the Thickness-Based Method (TBM). A well-known CST parameterization method is used to introduce an efficient way to determine the design parameters. This method ensures the generation of feasible geometric airfoils for thickness constrained optimization problems, leading to a more efficient optimization process. The method is evaluated through different optimization cases and algorithms. The optimization processes were implemented using the integration platform modeFRONTIER.

BENEFITS - A significant improvement of up to 50% at the convergence rate of the objective function was observed in both gradient-based and gradient-free methods by the application of the TBM method in comparison to the CST one. The increase in optimization efficiency highlighted in this paper are based on single airfoil optimization examples, therefore if a typical wing design is performed using several airfoils, the usage of a method such as TBM can save considerable amount of computational resources.