Method for efficient feasibility study of air cooling systems for modern PMSM electric motors in all-electric aviation

In this paper, the authors present a computational model of a fin-based air cooling system for Permanent Magnet Synchronous Machine (PMSM) electric motors. The model can be used as a method for fast and efficient feasibility studies of air cooling for PMSM motors in hybrid-electric or all-electric aviation applications, supplementing further research (thermal resistance networks, and FEA/CFD-CHT models). In the paper, authors provide temperature distributions along the fin height which are calculated and presented for a straight fin, followed by heat transfer rate from fin surface and fin efficiency. A parameter to compare different fin materials for aviation applications is introduced – heat transfer rate from the fin to fin mass ratio. Aluminum and copper fins are compared. Different shapes of straight fin are considered and compared. The above parameters and comparison are then calculated and given for circular fins. Parameters of the whole fin-based air cooling system for specific 140 kW PMSM motor are calculated and presented.