System-level modelling and safety assessment of a liquid hydrogen fuel cell regional aircraft

Hydrogen is increasingly making its way into the aviation industry as an opportunity to reduce emissions. Liquid hydrogen fuel cell aircrafts represent a promising technology to pursue the path toward decarbonization. Hydrogen holds great potential as a means of generating electrical energy and powering air transportation; however, it also poses significant challenges to overcome and stringent requirements to be met to reduce associated risks. Safety concerns are indeed a crucial aspect that greatly influences architectural choices. The thesis aims to analyse the safety aspects of a liquid hydrogen PEM fuel cell regional aircraft with a Model-Based System Engineering (MBSE) approach. A reference aircraft is taken into consideration to execute a safety assessment process, identifying potential failure conditions that could compromise flight safety. A functional model of the system architecture is developed with the tool Capella, based on the Arcadia MBSE methodology. The model does not focus on detailing the physics of the components to optimize the design but rather acknowledges their roles within the architecture, their requirements and their constraints. A Functional Hazard Assessment (FHA) is conducted on the system of interest, which includes the Energy generation system, the dedicated Thermal management system and the Energy storage system. The analysis provides an overview of possible failures of all the functions of the system, classifies their severity, and offers a deeper understanding of the requirements of the system, which can be integrated into future design phases.