Combined Aerodynamic and Structural Optimization of a High-speed Civil Transport Wing

A combined procedure for the aerodynamic and structural optimization of a High-Speed Civil Transport wing is presented. Primary goal of the procedure is the determination of the jig shape of the wing necessary so that it deforms into its optimum shape in cruise flight. The wing twist and camber distribution is optimized for the cruise condition using WINGDES, a code based on a linearized potential flow solution for zero-thickness lifting surfaces. The structural design is decomposed into three levels. The top level uses the FLOPS aircraft synthesis program to generate preliminary weights, mission, and performance information. The optimization criterion is productivity expressed by a productivity index for the specified mission. The second level of the system performs a finite-element based structural optimization of the wing box with the help of the ASTROS structural optimization tool. The wing structure is sized subject to strength, buckling, and aeroelastic constraints. The buckling constraint information is supplied by the third level where a detailed buckling optimization of individual skin cover panels is performed. The Georgia Tech HSCT baseline aircraft is presented and the resulting optimum wing structure, cruise and jig shapes are explained in detail.