Passive Thermal Management Through Vapor Chamber Integration of a PMSM E-Motor installed on UAV for Urban Mobility Applications

Thermal management represents a critical design aspect for Permanent Magnet Synchronous Motors (PMSMs) employed in Unmanned Aerial Vehicle (UAV) propulsion systems, where high power density and compact integration lead to significant heat generation. Excessive temperatures may compromise efficiency, reliability, and lifetime, making effective yet lightweight cooling strategies essential. The integration of a vapor chamber is investigated as a fully passive thermal management solution for a commercially available PMSM intended for UAV applications. Unlike active cooling systems, the proposed approach does not require moving parts, external power supply, or additional control devices. The vapor chamber operates through phase-change heat transfer mechanisms, enabling an enanched heat dissipation, exploiting the whole external surface of the vapor chamber; consequently the system naturally adapts to local thermal loads and provides self-regulating behavior without auxiliary components. A simplified three-dimensional model of the motor was developed, and steady-state conjugate heat transfer simulations were performed to evaluate the thermal response of the system. Two configurations were compared: a baseline motor housing and a configuration integrating a vapor chamber within the external structure. The vapor chamber will be modeled through a three-dimensional approach in which the wick region is represented by means of an equivalent porous medium formulation. The comparative analysis demonstrates the effectiveness of the vapor chamber in enhancing temperature uniformity and heat rejection while maintaining structural simplicity. The integration of passive vapor chamber technology may represent a promising approach for compact packaging and layout optimization in UAV electric propulsion systems.