Feasibility study of an induction motor rim drive for an aircraft boundary-layer-ingestion fan

This study presents a feasibility study for an induction motor rim drive to power aircraft boundary-layer-ingestion (BLI) fans. The design is developed from a BLI-fan specification for traditional aircraft architecture: the rotor is fastened to the rim of the blade shroud, not to obstruct the fan duct and interfere with the air flow. The main objective of this study is the identification of achievable power density and efficiency levels with an induction motor rim drive configuration considering the structural requirements for the integrity of the rotor operating with high tip speeds. The proposed 250 kW, 14,000 rpm design example achieves an efficiency in excess of 97% with an active mass around 20 kg.