Three-dimensional Simulation of Forced Convective Flow and Heat Transfer in Air-Cooled Motor Stator

The reliable prediction of cooling medium velocity and stator temperature distribution is very important for a running motor to ensure the temperature rise of stator below the limit. In this paper, taking the stator ventilation duct of an air-cooled motor as the research object, a 3D physical model including the iron core, the windings, the stator ventilation duct and the main insulation was established. In order to fully reveal the characteristics of forced convective flow and heat transfer in air-cooled motor stator, the fluid field and temperature field were calculated by using finite volume method. The radial and axial distribution characteristics of the fluid field were analyzed deeply. It's shown that the velocity decreases in the axial direction on the half of the axial plane and varies greatly in the radial direction. The temperature distribution in the main insulation layer of the stator was elaborated emphatically. The temperature of the insulation material along the length of the slot and the temperature difference between inner and outer insulation were discussed in detail. Based on the experimental results, the reliability of the calculation method was evaluated and the relative error is within 15%.