A Hybrid CFD-LPTN Thermal Modeling Approach for In-Slot Evaporative Cooling in Electrical Motors

This article presents a hybrid thermal modeling approach combining Computational Fluid Dynamics (CFD) and Lumped Parameter Thermal Network (LPTN) for the thermal analysis of in-slot evaporative cooling systems. Firstly, a Volume of Fluid (VOF) based numerical model is established to characterize the boiling heat transfer under various slot geometry parameters. Subsequently, a heat transfer correlation is derived to decouple the effects of heat flux and geometry parameters, which is then integrated into the LPTN model. The comparative results demonstrate that the proposed hybrid model achieves high-fidelity thermal prediction with significantly reduced computational cost. Furthermore, the parametric analysis identifies an optimal channel design that effectively balances the trade-off between convective heat transfer area and volumetric heat generation.