Knowledge-based engineering methods for hydrogen tank and system integration in aircraft fuselage design

Integrating new technologies such as liquid hydrogen as an energy carrier is a key step toward climate-neutral and sustainable aviation. Current research mainly focuses on integrating cryogenic hydrogen tanks in the rear fuselage section. This paper presents an extended knowledge-based engineering (KBE) framework that enables the automated modelling and assessment of hydrogen tank integration concepts in preliminary aircraft design. The framework integrates several stages of the preliminary aircraft design process. Starting with openAD, a design synthesizer for determining the aircraft outer mold line and tank positions, followed by the Fuselage Geometry Assembler for generating structural, cabin, and cargo geometries as well as the Systems Architecting Assistant and GeneSys for system sizing and integration. Data exchange between these tools is realized through an XML-interface, and geometric consistency is ensured using the Open Cascade Technology library. Parametric data exchange with simulation environments is supported via CAD-exchange formats and the Common Parametric Aircraft Configuration Schema. The newly developed methods enhance an existing KBE-based fuselage design system with experimental tank mounts, crash structures, and hydrogen distribution systems. These additions enable a consistent and fully automated generation of structural and system models at the required fidelity level for future disciplinary analyses. The proposed method is demonstrated in a preliminary design study of two liquid-hydrogen-powered aircraft configurations, highlighting the improved automation, consistency, and integration capabilities of the extended KBE framework.