Parameterization of Curvilinear Spars and Ribs for Optimum Wing Structural Design

摘要

A parameterization of the aircraft shape is needed for a correct mathematical definition of the structure and its components. The parameterization allows the definition of the geometry as a function of a few meaningful parameters. Traditionally, the aircraft industry focused on developing a universal parameterization of the aircraft outer mold line to facilitate the automatic construction of complex aerodynamic meshes to be used in computational fluid dynamics calculations and aerodynamic shape optimization problems. More recently, the attention of researchers has shifted toward the internal structure topology parameterization. The introduction of new design concepts such as SpaRibs (spars and ribs) requires the capability to define the geometric shape of the internal wing components for a correct automatic generation of the finite element mesh. The aim of this research is to present a simple and efficient way to parameterize the topology of the internal structure of complex wings. Spline curves are used to define the shape of each SpaRib in the natural space. The spacing between two SpaRibs is determined by the common ratio of a geometric progression. The parameterization of the topology of the internal structure of a simple quadrilateral wing box is presented. The same parameterization is then extended to the placement of SpaRibs in a generalized shape wing. The parameterization is used to place SpaRibs in the outer mold line of a high-speed commercial transport aircraft for structural optimization.