Low Reynolds number high-lift airfoil design for HALE concept UAV

This paper is focused on the design and analysis of a new laminar flow airfoil for a high-altitude long-endurance concept aircraft. It is expected that the new designed airfoil have the maximum possible thickness and the best polar performance at relative low Reynolds numbers. The powerful inverse design methods can efficiently produce the anticipant airfoil shapes by solving the classical inverse problem of determining the aerodynamic shape that will produce given pressure distributions. For a successful design, the translation of the design goal into a properly defined pressure distribution which usually exhibits the required aerodynamic characteristics is a difficult problem. Aimed at this purpose, a Genetic Algorithm (GA) has been employed to optimize target pressure distributions for aerodynamic inverse design methods in the current study. Once the target pressure distributions are obtained, the corresponding airfoil geometries can be produced by an inverse design method. This paper outlines the design procedures. It was shown from the design samples that the design efficiency has been improved by providing the designer with tools for target pressure specification.