Enhancing UNICADO’s systems design methodology for future aircraft energy supply architectures

Abstract In response to the imperative to reduce aircraft emissions, future propulsion systems are anticipated to undergo significant changes. Conventional propulsion systems typically supply onboard systems with shaft power and bleed air. As propulsion systems change, onboard systems may draw power from bleed-less engines, batteries, or hydrogen fuel cells, requiring system architecture and sizing adjustments. This paper uses a model-based approach to enhance the systems design module of the aircraft design software UNICADO to allow the modeling of such system architectures and investigate their effect at the aircraft level. The new methodology provides a graphical architecture definition using the SystemXF systems modeling approach. On this basis, a model-based safety assessment can identify safety issues and thus help to find suitable architectures. Power flow routing details the linkage between the power source and consumer systems through energy distribution systems and, hence, allows for a more precise and flexible representation of the aircraft system architecture. The introduction of energy-based interfaces, independent of specific power sources, allows for user-defined energy exchanges— such as engine offtakes, electrical power, or fuel— between system design and overall aircraft design. The approach is validated with a conventional architecture similar to that of the A320 and a system architecture powered in part by a fuel cell APU demonstrates the versatility of the enhanced systems design module.