Multi-disciplinary and multi-objective optimization of an unconventional aircraft concept

The aerospace engineering typically deals with multidisciplinary complex systems, and narrow margins of the design parameters make necessary the introduction of optimization approaches in order to pick optimal designs. In the present paper, an integrated computational environment has been implemented for the Multidisciplinary Design Optimization (MDO) of a non-conventional aircraft concept comprised of fuselage, tail and wing. The problem has been solved through an explicit Multi-Objective Optimization (MOO), where the optimization criteria include minimum Empty Weight and minimum Fuel Weight, taking into account of structural, aeroelastic and mission constraints. The level of fidelity for the involved disciplines is a relevant issue when iterative analyses are addressed and a compromise between high-delity and computational burden should be found. In the present paper high-fidelity analyses for the structural and aeroelastic assessment, together with middle-fidelity analyses for the aerodynamic, mission and performance analyses are performed. A complex MultiDisciplinary Analysis framework is proposed, in order to account for the interdisciplinary interaction and to provide self-consistent analyses. In this work Multi Objective Genetic Algorithm (MOGA) is applied for evaluating the Pareto frontier in the objective space of Empty Weight and Fuel Weight for the Over-the-Wing-Nacelle concept. This gives the designer a good overview of a multidisciplinary problem because it allows one to quantitatively model the coupling between the disciplines, in terms of constraints, design variables in uences, and possible trade-offs among the objectives.