Thermal, Structural, and Rotordynamics Refinements to the Superconducting Rotor of a 1.4 MW Partially Superconducting Machine for Electrified Aircraft

NASA is developing the high efficiency megawatt motor (HEMM), a 1.4 MW partially superconducting machine, to address the need for highly efficient, lightweight, MW-class machines to support aviation sustainability efforts. This paper presents progress on the thermal, structural, and rotordynamics aspects of HEMM's superconducting rotor. A thermal model of the rotor is correlated to existing data from a thermo-electrical test of the rotor using emissivity measurements of gold-coated rotor parts. Sources of error in the uncorrelated thermal model and lessons learned from the correlated model are presented. An updated structural design of the HEMM rotor is presented and compared to the prior design. Finite element analysis demonstrates that the updated design improves stress margins while reducing magnetic flux leakage and retaining thermal performance. The key conclusions of the rotordynamics design are presented.