A FULLY AUTOMATED CAD-BASED FRAMEWORK FOR SHAPE OPTIMIZATION

Kurzfassung

In the area of aircraft design, many studies about Multi Disciplinary Optimization (MDO) and Multi Objective Optimization (MOO) have been published in the last decade. However, there are some concerns that prevent the use of many developed optimization tools in a real aircraft design process. These issues are simply a lack of functionalities of treating surface/surface intersections and geometrical constraints, and difficulties of applying design knowledge to the real aircraft design that are the fundamental features for MDO and MOO. In this study, a new shape parameterization framework is proposed to overcome these issues by establishing a geometry parameterization method based on a NURBS formulation that is used in nearly any state of the art CAD software, and utilizing the Free Form Deformation technique to deform the aircraft shapes arbitrary with a moderate number of design variables. With the developed shape parameterization based on NURBS in combination with a newly developed surface grid deformation approach, optimizations have been carried out for the DLR-F6 wing/body/nacelle/pylon/configuration. A significant drag minimization has been achieved in cases with and without geometrical constraints. It is demonstrated that this approach will be an essential design tool in practical aircraft design.