The optimization of supersonic aircraft structures needs to address different aspects of the design as the internal structural layout, the sizing of the structural components, the aerodynamic loads developed for the given flight conditions and the aeroelastic response of the structure. In particular, the study of the interaction between the structure and the aerodynamics is critical for designing large supersonic transport aircraft and must be considered in an optimization framework which aims to obtain more efficient wing structures. In this paper, the SpaRibs design concept is implemented in a multidisciplinary optimization framework including structures, static aerodynamics and nutter analysis, in an effort to reduce the weight of a baseline supersonic transport aircraft, given structural and aerodynamic/aeroelastic constraints for given flight conditions. The framework incorporates global optimization and local optimization loops which are executed following a two-step optimization process and interact in a synergetic manner for the efficient computation of the responses required by the design process. The main purpose of the global optimization loop is to optimize the internal structural layout using the SpaRibs. In other words, the topology of the wing is changed during the global optimization. However, the responses computed depend also on the size of the structural components and not only on the layout. In particular, the aerodynamic loads and the aeroelastic responses of the structure are different for wing structures characterized by the same internal layout but different thickness distribution. The purpose of the local optimization loop is to compute the best thicknesses of the structural components given a fixed structural layout. In this phase each panel of the skin is optimized to satisfy stress constraints. A detailed description of the overall process is given by the authors along with a set of results obtained by applying the framework for optimizing a realistic supersonic wing structure.
展开▼
