Development of a NURBS-based wing design optimization system

A three-dimensional wing aerodynamic design optimization procedure was developed based on the NURBS (non-uniform rational B-spline). The procedure includes NURBS-based wing geometry generation module, NURBS-based grid generation system, inviscid Euler equations solver and numerical optimization algorithm. The convex hull, local support, shape preserving forms and the variation diminishing properties of NURBS gives an excellent capability of wing geometry design. The current procedure also offers accurate geometry data transferring from the design optimization system to any CAD system since all the geometrical entities in the procedure involves the parametric based NURBS, which is accepted as the standard for the geometry definition in IGES (initial graphics exchange specification). The application of the procedure to the transonic wing design shows a reasonable result in the aspect of reduced wave drag due to the weakened shock strength on the upper surface.