High-Fidelity Aircraft Fuselage Design Framework Coupling Internal Layout with Aerodynamic and Structural Analyses

Fuselage outer mold line (OML) design strongly affects aircraft drag and structural weight, but the OML must also accommodate the internal layout and installation constraints of onboard components. Although high-fidelity aerodynamic and structural analyses are needed to capture flow separation and complex load paths, integrated fuselage design methods that account for constrained internal layouts remain limited. This study develops a layout-informed high-fidelity fuselage design framework that links constrained internal layout generation with aerodynamic and structural design. First, an enhanced heuristic layout design algorithm is introduced to efficiently arrange internal components while satisfying installation and packaging constraints. Second, a layout-informed baseline modeling approach is proposed to transfer the resulting internal layout to the aerodynamic and structural models, thereby defining the spatial constraints for OML design and the geometry of internal structures. The proposed methods are coupled with existing high-fidelity aerodynamic and structural design frameworks and applied to the fuselage design of an electric vertical takeoff and landing aircraft. Relative to the case using the baseline OML and baseline internal layout, the integrated design reduced total drag and structural weight by 35.5% and 13.2%, respectively. Compared with the aerodynamic design case using the baseline internal layout, the integrated design with internal layout optimization further reduced drag by 13.3%. The results also show that aerodynamic optimization without structural considerations can drive the OML excessively close to the internal layout, leading to substantial structural weight penalties. These findings demonstrate that layout-informed fuselage design is essential for obtaining aerodynamically efficient and structurally feasible fuselage designs.