Multi-Fidelity Maneuver and Gust Loads Analyses of a High Aspect Ratio Jet Transport with Laminar Wings

Kurzfassung

The ULTIMATE-NLF is a high aspect ratio jet transport aircraft featuring a laminar wing, developed under the German LuFo-funded ULTIMATE project. The wing design combines an aspect ratio of over 15 with an innovative Crossflow Attenuated Natural Laminar Flow (CATNLF) configuration. A key challenge is the structural design of the highly flexible wing, as aeroelastic effects must be addressed throughout the entire design process. Conventional transport aircraft load and sizing processes rely on potential aerodynamic methods (e.g., VLM, DLM) to efficiently compute hundreds of load cases. However, these methods fail to capture nonlinear aerodynamic effects - such as flow separation at high load factors and large gust gradients - which significantly impact loads in transonic flight conditions. This work presents a hybrid approach for the structural optimization of the ULTIMATE-NLF wing, combining conventional potential flow methods (MSC Nastran SOL144,146) for initial load calculations with high-fidelity CFD (RANS, URANS) simulations applied to critical regions on the convex hull.