Initial Sizing Methodology for Hybrid-Electric General Aviation Aircraft

Electric and hybrid-electric propulsion offer unique possibilities to improve aircraft efficiency and performance. The potential advantages are fuel savings, lower emissions, and reduced noise. Because hybrid-electric aircraft generally apply multiple power sources, they can be designed to sustain flight if certain parts of the propulsion system fail. However, their additional degrees of freedom increase the complexity of the design process. This paper describes a methodology of an initial sizing algorithm that considers aircraft with hybrid-electric propulsion systems. A central element is a modified constraint diagram, which matches the power-to-weight ratio, wing loading, and the hybridization of power . It is coupled with a mission performance analysis that is capable of dealing with multiple energy sources and defines the mass and size of all relevant aircraft components. The modified constraint diagram also allows a visual assessment of the sizing results, and thereby greater insight into the design space.