A Study On Two-level Optimization Approach For Aerodynamic Design Of Wing Shape

The flight performance of aircraft is strongly influenced by its aerodynamic characteristics. Therefore, designing optimal aerodynamic shape of the wing becomes one of the main tasks of aircraft design. Traditionally, aerodynamic shape design optimization of the wing includes two approaches. One is contour optimization which means that the contour parameters of the wing are optimized to obtain optimal aerodynamic performance given the airfoil. The other is section optimization which means that wing sections (airfoils) are chosen or modified to achieve optimal aerodynamic performance for the given contour parameters of the wing.This paper proposes a two-level optimization approach for aerodynamic design of aircraft shape. The approach is simple in terms of flowchart and has the ability to conduct both the contour and the section optimization simultaneously. The approach is divided into two levels including contour optimization and section optimization: the contour optimization passes the contour parameters to the level of section optimization and its objective is to find the optimum contour; the section optimization is aimed to find the optimum section shape for the given contour parameters and feedback optimization results to the level of contour optimization. This two-level approach is able to find out the optimum shape including both the contour and the section shape.The aerodynamic optimization of the wing of a general aviation aircraft was used to verify the approach. The aerodynamic optimization of the wing of a civil regional jet was studied using the proposed approach. The results indicated that this approach could reduce the drag and obtain optimum aerodynamic shape of the wing under the given constraints such as wing structure limitation and internal volume and so on.