Thermal enhancement of an air-cooled motor with a flow guide

A cooling system with a flow guide is proposed to enhance the winding cooling of an air-cooled motor. Thermal and flow modeling was performed using computational analysis and the results are validated through experiments. In addition, the effects of the flow guide installation on the flow and heat transfer characteristics inside the motor are analyzed. The variation in the cooling effect and pressure drop ratio with various design factors at experimental points selected based on the design of experiments are investigated through numerical analysis. When a flow guide is installed at the rear cavity of the motor, the cooling air directly cools the winding end-turn, thereby reducing the winding temperature. The installed flow guide reduces the pressure drop by enhancing the cooling path. Optimization was conducted to obtain the optimal design points of the flow guides based on the numerical data. Correlations are proposed to establish the design criteria for maximizing the winding cooling for different types of flow guides. The use of these correlations results in the improvement of the cooling effect by up to 28% without the degradation of flow rate due to increased pressure drops. (c) 2021 Elsevier Ltd. All rights reserved.