Case Studies in Initial Sizing for Hybrid-Electric General Aviation Aircraft

This paper showcases the potential influence of hybrid-electric propulsion systems on the performance of general aviation aircraft. Using the Cirrus SR-22 as a baseline, parallel- and serial-hybrid propulsion configurations are explored. For these case studies a high level approach is chosen, using an innovative initial sizing methodology to determine weight or energy consumption of new aircraft concepts. Mission parameters and aerodynamic performance are varied and the impact on aircraft fuel and energy consumption, as well as on take-off mass is studied. The studies' results indicate that hybrid-electric aircraft consume less energy than conventionally propelled designs for certain missions. However, the aircraft's design point, in terms of wing loading and installed power must be changed: Hybrid-electric aircraft should be sized with a higher power-to-weight ratio and a higher wing loading than their conventional counterparts.