A multilevel decomposition procedure for the preliminary wing design of a high-speed civil transport aircraft

A Multidisciplinary Design Environment is developed that decomposes the wing design process from the system level (aircraft) to the subsystem level (wing) down to the component level (wing skin cover panel) in a three-level structure. The linking of conceptual and preliminary design tools of different levels of fidelity is demonstrated, as well as processing higher-fidelity information at the conceptual synthesis level. The MDO environment is developed as a modular, open framework that will permit the integration of additional disciplinary modules in the future. The methodology is verified with two test cases, the BAC-Sudaviation Concorde and a Lockheed supersonic cruise configuration study. It is then applied to the design of a High-Speed Civil Transport configuration for 250 passengers and a design range of 6500 nm. After two full iterations through the multilevel procedure, convergence is reached and the objective function, the productivity index of the aircraft, is increased by approximately 15% over the baseline configuration with a reduction in gross weight of about 10%. The final configuration exhibits an increased cruise Mach number of 2.5, a smaller wing, and slightly smaller aspect ratio than the baseline configuration. The system level optimizer trades aerodynamic performance against structural weight savings, resulting in a final configuration with a considerably lower wing structural weight at almost constant fuel weight. At the current technology level, further improvement does not seem possible; however, the procedure developed in this work provides an efficient tool to rapidly explore the impact of new technologies in structures, aerodynamics, and propulsion on the overall performance of modern supersonic transport configurations.