More Electric Engine Technologies Towards the 2040s

Improvement and evolution of all aircraft technologies and the commercialization of new technologies are essential to the carbon-net-zero goal of air mobility. Passenger aircraft are required to provide the ultimate in comfort, economy, and safety, and gas turbine engines will not disappear, while promoting the conversion to SAF and hydrogen fuels. The More Electric Engine (or MEE) concept, which has been proposed since the late 2000s, is one alternative. This paper focuses on the electrification of engine accessories. When the concept of electrification of engine accessories was first presented at Aerotech 10 years ago, the discussion at Aerotech seemed to be negative. Attaching a motor to conventional engine accessories would obviously increase the weight. Next, the conventional engine accessories are centrally controlled and only FADEC is in command, but electrification of engine accessories will increase the cost by adding intelligence to all the accessories. On a more academic level, a complete solution for the multiplicity required to ensure safety has not yet been clearly defined. Currently, electrification of engine accessories is not on the list of practical scenarios as far as the authors are aware. MEE is not only a technology that simply replaces power with electricity but is also a necessary technology to improve performance while keeping up with the latest technologies. Electrification and intelligence are inseparable due to their physical characteristics, and various industrial machinery systems and mobility systems have been innovated to take advantage of this relationship. This paper summarizes the concept of MEE technology required for aircraft in the 2040s and beyond, and the research results necessary to realize it. Finally, the background of how MEE can be used as a useful technology in the practical application of SAF and hydrogen-based fuels, which are realistically required in the 2040s and beyond, is summarized.