Multidisciplinary Aeroelastic Optimization of High Aspect-Ratio Composite Aircraft Wings via Tow-Steering

Innovative high aspect-ratio airframe designs are leading the way to a more sustainable future in aviation. These configurations enhance aerodynamic efficiency by reducing induced drag. Further performance improvements, especially regarding structural mass, are achieved with composite material airframes, that have been used progressively more in the aerospace industry due to their superior performance, lightweight design and inherent ‘tailorability’. On that end, towsteered composites have recently shown to enhance performance compared to conventional composites by taking advantage of the anisotropic behavior of fiber composites. However, these advancements can result in undesirable effects and specifically aeroelastic couplings due to increased flexibility, making the design and optimization of such airframes highly complex and computationally demanding. In our approach, a computational framework for the aeroelastic optimization of a composite high aspect-ratio commercial aircraft wing is proposed. Initially, we explore the effect of tow-steered composite skins on the mass of a fully-sized reference wing compared to conventional composites and subject to multidisciplinary constraints. We then aim to further investigate the effect of steered composites in various disciplines and thus introduce two single sub-optimization problems, namely the minimization of the stress aggregate function on the skins as well as the maximization of the flutter velocity. Finally, a multi-objective problem is formulated for the simultaneous optimization across three objectives. Multiple gains in performance are observed across all of the objectives in the aforementioned optimization problems, indicating the positive effect of tow-steered composites in the design of high aspect-ratio wings.