High Aspect-Ratio Composite Wing Aerostructural Optimisation of a Short-Medium Range Aircraft

Abstract

A key pathway towards climate-neutral aviation lies in the adoption of high aspect-ratio wings, which reduce lift-induced drag. A recently developed high-fidelity multidisciplinary design optimisation framework, incorporating DLR's aerodynamic TAU solver and Airbus' structural Lagrange solver, is used for the aeroelastic structural sizing optimisation of two high aspect-ratio composite medium-range transport aircraft wings. Three distinct objective functions are considered: i) the classical minimisation of mass, ii) the maximisation of aerodynamic efficiency, and iii) the maximisation of Breguet range. A gradient-based algorithm with direct sensitivity analysis is used. The design variables include structural sizing parameters such as the thickness or cross-sectional area of the skin, spars, and stringers. Constraints reflect industry requirements, encompassing structural strength, buckling stability, and manufacturing criteria. For the objective functions and design points analysed, the findings highlight the advantages of high aspect ratio wings in reducing drag and improving aerodynamic efficiency, despite the increase in structural weight. Optimising for Breguet range results in a trade-off between structural and aerodynamic efficiency, demonstrating the benefits of considering a multidisciplinary performance-based objective for structural sizing in the preliminary design phase.