Thermal Analysis of an Aviation Air Compressor Motor at Different Flight Altitudes

This paper discusses the heat transfer mechanism inside the motor, the motor's heat generation mechanisms - copper losses, core losses, and convective-radiative dissipation - are modeled using Fourier's law, Navier-Stokes equations, and Stefan-Boltzmann law. And then investigates the changes in thermal behavior of a permanent magnet motor for aviation air compressors caused by changes in the physical properties of air caused by increasing altitude. A computational fluid dynamics (CFD) thermal simulation was carried out for an aviation air pressure pump motor with high flight altitude. Through the analysis of the simulation results, it is found that the increase in altitude will reduce the natural convection heat dissipation performance of the motor. If the altitude rises from 10km to 20km, it will lead to a 25.2% decrease in the natural convection heat dissipation performance, and this change is non-linear, which is mainly due to the air density, viscosity and thermal conductivity caused by the increase in altitude. Caused by the decline in coefficients. The study concludes that conventional natural convection cooling becomes insufficient above 16,000 m, necessitating emissivity-enhanced surfaces or hybrid thermal management for reliable motor operation.