The rise of electric propulsion systems has pushed aircraft designers towards new and potentially transformative concepts. As part of this effort, NASA is leading the SCEPTOR program which aims at designing a fully electric distributed propulsion general aviation aircraft. This article highlights critical aspects of the design of SCEPTOR's propulsion system conceived at Joby Aviation in partnership with NASA, including motor electromagnetic design and optimization as well as cooling system integration. The motor is designed with a finite element based multi-objective optimization approach. This provides insight into important design tradeoffs such as mass versus efficiency, and enables a detailed quantitative comparison between different motor topologies. Secondly, a complete design and Computational Fluid Dynamics analysis of the air breathing cooling system is presented. The cooling system is fully integrated into the nacelle, contains little to no moving parts and only incurs a small drag penalty. Several concepts are considered and compared over a range of operating conditions. The study presents trade-offs between various parameters such as cooling efficiency, drag, mechanical simplicity and robustness.
Design of an Electric Propulsion System for SCEPTOR
2016
30 pages
Report
No indication
English
Space Technology , Unmanned Spacecraft , Manned Spacecraft , Nacelles , Electric propulsion , Cooling systems , Design optimization , Systems integration , Computational fluid dynamics , Air cooling , Propulsion system configurations , Propulsion system performance , General aviation aircraft , Tradeoffs , Electric motors