Numerical Study on the Impact of End Windings Porosity on the Fluid Flow and Heat Transfer in a Totally Enclosed Fan-Cooled Electrical Machine

A critical review on thermal management technologies for motors in electric cars

“…Despite the research presented here, the heat transfer characteristics of convection heat transfer of end winding in end space have not been fully revealed, and further effort is still needed. It was suggested that the cavities in the end winding provided additional heat transfer paths and small variations of cavities could cause significant variations of the heat transfer coefficients [94,95]. Nevertheless, the cavities are difficult to accurately model even with CFD methods, not to mention LPTN models.…”

Development of a Thermal Analysis Tool for Linear Machines

“…It is hard to calculate the heat transfer coefficient analytically in regions with complex geometries, such as the end windings or the airgap. Thus, CFD simulations are often used to predict the operating temperatures of electrical machines [5][6][7][8][9][10][11]. However, as this technique requires high com-putational capabilities, the geometries of electrical machines are often simplified by means of symmetries and periodicities [5].…”

“…Nonetheless, the usage of these tools is essential for obtaining detailed results of especial heat exchange region configurations. For example, the influence of the end winding porosity in the heat transfer of the end region of a totally enclosed and fan cooled machine is analyzed in Reference [10]. The results show that increasing the porosity of the end windings from 3.7% to 15.2% can reduce the thermal resistance between the end windings and external the frame in 28%.…”