Mapping the Potential of Hybrid Electric Architectures for Commuter Aircraft

Abstract Hybrid electric aviation is a possible step toward sustainable flight. Several hybrid architectures and synergetic concepts have been investigated. However, environmental performance results seem to be inconsistent due to deviations in technology assumptions and a mismatch between the fidelity of methodologies used for simulation of different aircraft systems. A multidisciplinary framework is developed, consisting of detailed modeling approaches for thermal and turbomachinery components, electrical power system design, aircraft/mission, and environmental analysis. The framework is employed for the investigation of an entry-into-service 2035 30 passenger commuter aircraft with a design mission of 1000 nautical miles. The investigation of parallel hybrid electric, turbo-electric, and series/parallel partial architectures is performed through a systematic conceptual design approach. The analysis reveals a bare minimum battery technology of 0.75 kWh/kg and 0.8 kW/kg, needed to compete with the conventional aircraft's performance. High degrees of hybridization (>20%) trigger the snowball effect of aircraft mass and thrust requirement, counteracting specific fuel and performance benefits generated by electrification. The turbo-electric and series/parallel partial concepts are paired with an electrically driven boundary layer ingestion fan. For those concepts to result in any block fuel and emissions benefits compared to conventional counterparts, a drag reduction from wake ingestion of 7.5–10% is required, with power split ratios between the electrically driven fan and propellers being limited to 15% due to extensive mass increase.