Development and Application of a CFD Framework for the Simulation of Fully Coupled Electromagnetic and Heat Transfer Process Inside Electric Motors

In recent years, the thermal management of electric motors for automotive applications became a key factor to further improve the motor performance and ensure its efficiency, durability and safety. As a matter of the fact, a motor overheat can result in various issues, including: demagnetization of magnets, degradation of insulation materials, decreased efficiency, shortened lifespan, and even motor failure. In this context, this work aims to improve the comprehension of heat generation phenomena in electric motors and to model the cooling circuit through the integration of CFD, in order to provide guidelines for the optimization of the overall system. To this scope, a novel OpenFOAM solver is introduced, capable of computing electromagnetic quantities and losses, consequently assessing heat generation across various motor components. The combined thermodynamic and electromagnetic analysis of the electric machine, which predicts the heat sources and temperature distribution under the effective electromagnetic operating conditions, allows to optimize the cooling system design and the thermal management strategy. The methodology is applied for the simulation of a simplified permanent magnet synchronous motor (PMSM), to improve the understanding of heat production and guide the development of efficient cooling mechanisms, with the ultimate goal of enhancing both its durability and performance.