Optimization of impeller blades of an electric water pump via computational fluid dynamics

Electric water pumps (EWPs) are characterized by small sizes and variable operating conditions. Efficient operation of such a pump is important for the whole thermal management system. Here, comprehensive hydraulic optimization was performed to improve the performance of an EWP. The computational fluid dynamics technique was used to assist in the optimization. The numerical scheme was validated using experimental data. Variations in the blade number, blade profile, and blade inlet edge were implemented. The results showed that solely increasing the blade number leads to an increase in the pump head but cannot guarantee high pump efficiency. A combination of adjusting the blade wrap angle and extending the blade inlet edge toward the pump inlet promotes increases in both the pump head and efficiency. With the improvement in pump performance, the characteristics of the flow field alter remarkably. The pressure at the blade inlet is reduced, and the turbulent kinetic energy near the impeller blade decreases overall.