Research on applicability of integrated design optimization in blended wing body aircraft

Requirements to produce environmentally friendly aircrafts that are efficient and capable of conveying large number of passengers over long ranges at reduced direct operating cost urge aircraft designers to develop the Blended Wing Body (BWB) concept. This kind of aircraft represents a paradigm shift in aircraft designs and provides many aerodynamic and structural benefits. To explore and exploit the enormous design potential and take the coupling effects of aerodynamics and structure into consideration, an integrated optimization method is presented in this paper to conceptually demonstrate its applicability in BWB aircrafts. The optimization aims at minimizing the stiffness of the outer wing of a BWB aircraft under the cruise condition subject to aeroelastic and aerodynamic constraints. The aeroelastic responses are calculated by MSC.Nastran and the flow field is estimated by the viscous/inviscid iteration method provided by MGAERO. The Genetic Algorithm is performed to search the optimal wing jig shape, beam position, and stiffness distribution of the representative beam-frame structure and the Kriging method is adopted to improve optimization efficiency. The sensitivity of the optimum is analyzed to study important parameters. The design results provide designers with a wealth of information and are significant reference for further designs.