Investigation into Potential Emissions Reduction via Small-Scale Hybrid Electric Aircraft Powertrain

Abstract

This project presents the design rationale for the development of a parallel-hybrid electric powertrain for an 84" remote controlled aircraft. The resulting powertrain utilized a 20cc internal combustion engine and 960 W electric motor connected via a planetary gearbox to produce approximately 100 N of thrust at maximum RPM. By comparing the performance of the hybrid-electric powertrain to a baseline 40cc internal combustion engine in terms of system mass, thrust, and lifecycle emissions, the potential benefits of a hybrid-electric powertrain could be assessed. Preliminary findings agreed with the existing literature on hybrid-electric architectures that the mass penalty associated with the battery and electrical system is the largest barrier to adoption for the technology, although promising results relating to the reduction of CO_ emissions were also discovered. Over the course of the project, the challenges and opportunities associated with a hybrid-electric powertrain were identified and presented to Pratt and Whitney, along with potential implications for scaling to agricultural, private, and commercial aviation. In this way, lessons gained when working with hybrid-electric architectures at a small scale could be applied to streamline the development of larger and more complex hybrid-electric systems.