Hybrid-Electric Propulsion for Aircraft

Against a background of increasing energy demand and rising fuel prices, hybrid-electric propulsion systems have the potential to significantly reduce fuel consumption in the aviation industry, particularly in the lighter sectors. By taking advantage of both electric motor and internal combustion engine, hybrid-electric propulsion systems provide not only a benefit in fuel saving but also a reduction in takeoff noise and the emission levels. This research considers the design and sizing process of a hybrid-electric propulsion system for a single-seat demonstrator aircraft, the experimental derivation of the internal combustion engine map, and the electric motor parameters. In addition to the experimental data, a novel modeling approach including several linked desktop PC software packages is presented to analyze and optimize hybrid-electric technology for aircraft. Further to the analysis of a parallel hybrid-electric, midscale aircraft, this paper also presents a scaling approach for a 20 kg unmanned aerial vehicle and a 50 ton intercity airliner. At the smaller scale, two different mission profiles are analyzed: an intelligence, surveillance, and reconnaissance mission profile and a maximum-duration profile. At the larger scale, the performance of a 50 ton intercity airliner is modeled, based on a hybrid-electric gas turbine, assuming a range of electric boost powers and battery masses.