From a Battery-Based to a PEM Fuel Cell-Based Propulsion Architecture on a Lightweight Full Electric Aircraft: A Comparative Numerical Study

The aviation sector is firmly committed to reducing harmful emissions and electric propulsion promises to tackle both pollution and noise at the same time. More Electric Aircrafts are progressively giving way to full electric aircraft that are expected to represent the next revolution in aviation. As is known, electric propulsion can be based on different electrochemical sources; nowadays, the widely used systems are developed on lithium battery packs, especially in automotive, where requirements in terms of gravimetric and volumetric energy densities are not so stringent compared to the aeronautical sector. Systems based on hydrogen fuel cells exhibit better performance in terms of range and endurance. In this article, a numerical study is presented on a lightweight electric aircraft, whose battery-based architecture is converted to a fuel cell-based architecture with the contribution of a battery pack that essentially intervenes in the take-off phase and, in addition, of a pack of ultracapacitors to prevent high discharge rate of the battery. The final intent is to explore the range extension without an increase in maximum take-off weight. The lumped parameter numerical models of the two propulsion systems have been developed in Simcenter Amesim where a set of simulations has been launched. It is shown that even under the constraint on the maximum take-off weight a significant extension of the range is obtained when adopting an electric propulsion system based on hydrogen fuel cells.