Numerical Optimization of Thermal Performance Using Kriging Method in a Propulsion Motor

초록

Compared to traditional radial flux permanent magnet motors, axial flux permanent magnet (AFPM) motors face challenges in air-cooled internal space design due to their compact internal structure. A separate, independent liquid cooling system is applied to effectively dissipate heat generated within the stator core and windings. This research employs computational fluid dynamics (CFD) and the Kriging method to analyze the thermal performance and pressure characteristics of AFPM motors with outer-rotating housings. The aim is to derive a thermal performance map and optimal design parameters for the cooling passage. For efficient analysis, the motor was simplified into a simple thermal model that includes the coolant passage, stator hub, core, and stator coil. CFD was adopted to predict the temperature distribution of significant components, focusing on coolant channel diameter and flow rate as parameters. The Kriging method was applied to derive a thermal performance map, and optimal design parameters were proposed using a utility function. Results indicate that increasing the coolant channel diameter by 0.9 mm and flow rate by 0.2 lpm reduces the hydraulic power required for coolant circulation by 62.1%. The maximum winding temperature stays within the permissible limit of 109 degrees C, and the thermal performance index improves by 49.3%.

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