CAD OPTIMZNTION OF GLIDER DESIGN WITH PROGRAM 'NAI 186'

Abstract

A cmputer-aided-design (CAD) program for glider optimization sizing at the preliminary design stage is described in this paper. This program was originally developed for optimization of light canard airplane design and had been used successfully in two designs of this type. The program has been modified to suit the mathematical models of glider at the preliminary design stage for optimization of sizing a glider. It utilizes constrained parameter optimization to minimize a performance index (e.g. gross weight of the glider) while satisfying operating constraints. The approach in the optimization uses geometric descriptors and mission parameters as independent design variables which are systematically iterated to find the optimum design. The constraints consist of geometric parameters, performances, trim conditions, static stabilities, handling qualities, and so on. All these parameters are calculated by the program. As a means of illustrating its use as a conceptual design tool, the optimization is used to perform a sensitivity study on design variable variations for a variety of design corstants and constraint functions.