| The purpose of this study is to develop a CFD based wing shape design optimization tool by utilizing Computer Aided Geometry Design (CAGD) techniques. A loosely coupled design optimization system is established with a generalized grid based flow solver for fluid dynamics and aerodynamic sensitivity, and a NURBS (Non-Uniform Rational B-Spline) based geometry description and grid generation.; The first part of this research concentrates on the derivation of a NURBS based geometric description of a wing with pertinent constraints, the automation of the grid generation, and formulation of associated sensitivity.; For the second part of this research, the sensitivity analysis of a nonlinear aerodynamics system has been performed by ADIFOR (Automatic Differentiation of Fortran Programs), which generates the automatic differentiation code derived from an existing flow solver. A widely accepted optimization package, ADS (A Fortran Program for Automated Design Synthesis) supported by NASA Langley Research Center, has been incorporated to perform the optimization bounded by the inequality constraints.; The initial validation of the resulting design tool is accomplished by exercising an inverse design problem involving Onera M6 wing and NACA four-digit airfoil section. (Abstract shortened by UMI.)... |
