This proposal focusses on the development of two high power density and high reliability asynchronous lift motors for Electric Vertical Takeoff and Landing (eVTOL) being relevant to the NASA Revolutionary Vertical Lift Technology (RVLT) Project. These motors are proposed in response to NASA’s A1.06 Vertical Lift Technology for Urban Air Mobility -Electric Motor Fault Mitigation Technology request of advanced technologies supporting electric/hybrid-electric propulsion for the advance air mobility, specifically, to the area of Single Fluid Motor with High Power Density and High Reliability.
The key issues in the Phase I/Phase II program are the redesigning - scale down of the present highly successful Ohio State University megawatt class induction motor to, (1) optimize overall design (poles, topology, size, etc.) from 1 MW class to a 200 kW class UAM eVTOL motor as well as, (2) to operate with single fluid bearings and (3) synergistically integrate the lubrication with cooling in order to operate a single fluid and to achieve maximum power density and reliability.
During this program, two full-size motors (shaft equivalent performances) with different coolants and cooling lubrication methods will be fabricated in order to allow a complete shaft-to-shaft testing program and an apple-to-apple comparative analyze of the two cooling/lubrication solutions. The first motor will use deionized water for both cooling and lubrication while the second motor will use a proprietary single fluid & semi-evaporative cooling and lubrication method.
At the end of Phase I, the electromagnetic circuits and the cooling/semi-evaporative cooling will be fully modeled and simulated, while all fundamental bearings aspects (tribological, dimensional, life estimation etc) will be addressed. A full design concept will be developed for both motors in order to assess/estimate the technologies, materials, fabrications and costs related to Phase II.
Assuming the goals of the proposed R/R&D are achieved, the innovations may be directly and immediately applied to the other area (the first area) of the A1.06 solicitations: Electric Machine/Motor Fault Detection and Fault Mitigation. In the meantime, such solution may be applied to: Megawatt electric propulsion systems in the A1.04 Electrified Aircraft Propulsion subtopic.
In addition to eVTOL, UAMs and electric passenger aircraft, NASA can benefit for many other lightweight applications as smaller land-based motors and generators.
The results of this work can lead to various applications related to high power density rotating machines. The weight saving feature is an important avenue for the electrification of various domains whit focus on transportation with immediate applications for aircraft turbo-generators, aero-propulsion motors, marine propulsion and portable emergency power systems.