Airfoil optimization with CST-parameterization for (un-)conventional demands

Abstract

For the development of modern airplanes new and “better” airfoils are needed. The design of a new airfoil is mostly done for a number of fixed design points by the inverse method and optimized by manual iteration. When changing the preliminary design of the airplane, the airfoil design parameters are changing continuously in the design process. Therefore a tool chain was created, which allows the parametric optimization of the airfoil and the connection with a 2D panel method with fully coupled boundary layer calculation (XFOIL) with an optimizer. This paper will show an approach for airfoil optimization using an enhanced parameterization method of the airfoil coordinates. It explains the tool chain and the influence of the parameters used. The validation results for optimizing typical main wing airfoils with and without camber changing flap are shown. Based on that validation for conventional airfoils, more complex airfoils for unconventional geometries can be optimized. First results for a high lift system on a morphing wing system for a sailplane are shown and discussed.