Structural Optimization of a High Aspect Ratio Transport Aircraft with Laminar Wing using High Fidelity Methods

Abstract

A high aspect ratio jet transport aircraft (ULTIMATE-NLF) with a laminar wing is designed within the project ULTIMATE funded by the German Federal Aeronautical Research Programme (LuFo). The design of the wing features both a high aspect ratio (15.6) as well as an innovative laminar airfoil layout with Crossflow Attenuated Natural Laminar Flow (CATNLF). A particular challenge is the structural design and optimization of the highly flexible wing due to the impact of aeroelastic effects, which must be considered throughout the whole design process. In this work we present an approach for the structural optimization of the wing of the ULTIMATE-NLF configuration that considers all relevant load cases requested by the CS-25 specifications (including steady and quasi-steady maneuver as well as unsteady gust loads) and uses high fidelity aerodynamic methods (RANS) to trim the aircraft for different mass cases and for the analyses of the aerodynamic performance during the iterative design process.