HSCT Wing Design through Multilevel Decomposition

Abstract

A multilevel decomposition approach for the preliminary design of a High Speed Civil Transport Aircraft wing structure is described. The wing 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 process is then verified with the help of data from supersonic transport studies performed by US aerospace companies in the 70s. Finally, an HSCT configuration based on the NASA HiSAIR H 24 e is optimized using the multilevel decomposition scheme. The gross weight is reduced by 9.5 %, and the productivity index, the system level objective function, is increased by 15 % for the most promising of the configurations analyzed.