Uncertainty Analysis for Hybrid Electric Propulsion in NASA EPFD Vehicles*

The National Aeronautics and Space Administration (NASA)'s Electrified Powertrain Flight Demonstration (EPFD) program aims to advance hybrid-electric propulsion (HEP) as part of the aviation industry's decarbonization efforts. However, the feasibility and performance of hybrid-electric aircraft are highly dependent on the development of key electrical components such as batteries, electric machines, and power converters, whose future capabilities remain uncertain. This paper presents an uncertainty quantification analysis of two hybrid-electric aircraft architectures: a turboprop aircraft and a turbofan aircraft. Using our established uncertainty propagation framework, we assess the impact of technological uncertainty on the design and performance of both vehicle configurations. The turboprop vehicle analysis builds on prior work, incorporating the latest iteration of the vehicle model, which was a retrofit study, while the turbofan analysis extends the framework to a revised model - incorporating an updated thermal management system along with a new operational mode for electric taxiing. The results indicate that hybridization offers promising benefits for the turboprop vehicle, whereas the potential advantages for the turbofan architecture appear less optimistic. The results indicate that hybridization offers promising benefits for the turboprop vehicle, whereas the potential advantages for the turbofan architecture appear less optimistic. These findings highlight the importance of tailored hybrid-electric strategies and demonstrate the utility of uncertainty quantification in guiding technology-informed design decisions.