In this proposal we propose to evaluate the performance of a novel configuration of superconducting electric motor. The application of this motor is propelling partially- or fully-electric aircraft. The technology has the potential to quadruple the existing state of the art in aircraft motor specific power. Gains in specific power come from several aspects of the design:
The axial flux configuration is used rather than the radial flux. Low-temperature superconductor (LTS) is used for the rotor rather than permanent magnets or high-temperature superconductor. The LTS is cooled via conduction cooling rather than helium-bath cooling. An optimized Halbach winding array concentrates magnetic flux and removes the need for back iron. A relatively high rotational speed allows for direct coupling to a propeller or ducted fan. A cryogenic Litz wire stator is used to reduce dissipation and heat transfer to the rotor. A relatively high pole count for a superconducting machine allows greater efficiency at higher electrical frequency.
In Phase I we propose to evaluate the principles using multiphysics modeling. We propose to design a 100 kg, 1 MW motor and a 1000 kg, 20 MW motor. For Phase II we would build and test the three test articles relevant to the 1 MW motor. A 1 MW motor coupled to a propeller is sufficient to replace a turboprop engine in a small business or regional airline aircraft. A 20 MW motor coupled to a ducted fan is sufficient to replace a jet engine in a large passenger aircraft.
This proposal is relevant to commercial aircraft fuel efficiency and emissions reduction, and electrification of aircraft propulsion. These are NASA technology roadmap Technology Areas (TA) of TA15.3.1, TA15.3.3, TA15.4.1, and TA15.4.2 and NASA Technology Taxonomies (TX) of TX01.3.4, TX01.3.8, TX01.3.9, and TX01.3.10.
A 1 MW motor coupled to a propeller is sufficient to replace a turboprop engine in a small business or regional airline aircraft. Roughly 600 of these aircraft are delivered per year. A 20 MW motor coupled to a ducted fan is sufficient to replace a jet engine in a large passenger aircraft such as the Boeing 737-800. High-power electric motors will be required for the DoD’s electric battlefield.