Effect of volute tongue angle on the performance and flow unsteadiness of an automotive electronic cooling pump

Automotive electronic cooling pump is the core component of the new energy vehicle cooling system, with the exclusive advantages of high efficiency and low vibration which will bring a broad market prospect. However, the rotor–volute interaction between impeller blades and volute tongue is a severe problem which can result in the performance degradation and unsteady flow fields of pumps. The influences of volute tongue angle on hydraulic performance and fluid stability are investigated in this study. The flow loss inside the pump is visualized by means of the entropy production theory, while the pulsations of pressure and radial force of the rotor are compared by unsteady computational fluid dynamics simulation. The results show that entropy production is an effective tool to visualize the loss distribution which allows accurate assessment of pump performance. Specifically, the pressure pulsation intensity near the volute tongue is larger and the main frequency of the radial force is the blade passing frequency. With the increase of volute tongue angle, the hydraulic efficiency under large flow conditions is improved, with an alleviated rotor–volute interaction intensity, and greatly reduced fluctuations of pressure and radial force. The main significance of this study is that it provides a new perspective to investigate the optimization design for automobile electronic cooling pumps.