Multidisciplinary optimization of an NLF forward swept wing in combination with aeroelastic tailoring using CFRP

Abstract

This article introduces a process chain for commercial aircraft wing multidisciplinary optimization (MDO) based on high fidelity simulation methods. The architecture of this process chain enables two of the most promising future technologies in commercial aircraft design in the context of MDO. These technologies are natural laminar flow (NLF) and aeroelastic tailoring using carbon fiber reinforced plastics (CFRP). With this new approach the application of MDO to a NLF forward swept composite wing will be possible. The main feature of the process chain is the hierarchical decomposition of the optimization problem into two levels. On the highest level the wing planform including twist and airfoil thickness distributions as well as the orthotropy direction of the composite structure will be optimized. The lower optimization level includes the wing box sizing for essential load cases considering the static aeroelastic deformations. Additionally, the airfoil shape adaptation based on sectional pressure distribution optimization and inverse design follows for the design point. Thereby, the objective function of the sectional pressure distribution optimization is the minimization of drag to find the best trade-off between profile drag considering NLF and transonic wave drag. First optimization results of the multidisciplinary process chain are presented for a forward swept wing aircraft configuration. At this stage, airfoil shape optimization has not been included yet. Instead, natural laminar flow is considered by prescribing laminar-turbulent transition locations.