Date of Award
Santa Clara : Santa Clara University, 2021.
Master of Science (MS)
Three different small aircraft, a Diamond DA40, a Cessna Skyhawk 172S and a Cirrus SR22, are used to assess the feasibility of converting an existing aircraft's power system to a serial-hybrid system or an all-electric system. The serial-hybrid system uses a gasoline engine to generate electricity that can power the main electric motor or charge onboard batteries, while the all-electric system uses batteries only and does not carry a gasoline engine. General system designs are proposed, and a calculation model was developed to allow for analysis of the three different aircraft and their variants. The all-electric and serial-hybrid variants are compared to the existing aircraft, the gas variant, by replicating the gas variant's performance on a representative flight plan as best as possible. Feasibility is evaluated on how well the variants perform relative to the gas variant and how power plant system weight, useable weight, endurance, range, and fuel consumption compare. Converting to an all-electric would reduce an aircraft's basic empty weight, but battery packs require large amounts of weight to achieve similar amounts of flight time. A serial-hybrid possesses a higher basic empty weight but will be able to trade battery pack weight for gasoline weight, and as a result can receive some benefits of an all-electric and benefits of an all-gas system. Performing a conversion of a gas system to an all-electric system would be difficult to achieve successfully without sacrificing significant performance such as speed and flight endurance. However, a serial-hybrid system conversion is possible, but flight endurance and range are sacrificed while fuel consumption is reduced. A serial-hybrid is useful in some scenarios, such as a training aircraft, due to low time per flight and short distances of flight, but a gasoline powered aircraft can travel farther and for longer due to the higher energy density of gasoline.
Rosenow, Kyle, "Feasibility Study of Serial Hybrid-Electric Systems in Small Aircraft" (2021). Mechanical Engineering Master's Theses. 41.