Convective Heat Transfer Characteristics on End-Winding of Stator Immersed Oil-Cooled Electrical Machines for Aerospace Applications

The stator immersed oil cooling has emerged as a promising thermal management method for high power density electric machines applied in aerospace applications. However, due to the complex geometry of end-winding, research on convective heat transfer coefficient (CHTC) flooded is still at infancy. This article investigates characteristics end-winding oil-cooled electrical by computational fluid dynamics (CFD) methods and experiments implemented motorette. variation law CHTCs with flow rate thoroughly investigated. Subsequently, new dimensionless correlations are defined using Nusselt numbers function Reynolds numbers, which further into detailed lumped-parameter network (LPTN) rapid evaluation temperature distribution. Finally, obtained simulation results verified local measurements. experimental also show that proposed structure can withstand current up 30 A/mm2 corresponding continuous 6.8 kW/kg.