Numerical Study on Radial Force and Pressure Pulsation of an Electronic Water Pump for Different Front Cavity Clearances

As the core of the thermal management system in new energy vehicles, the operational reliability of electronic water pumps directly affects vehicle thermal safety. Radial force and pressure pulsation, as key indicators, significantly impact the operation of the rotor system in electronic water pumps. However, existing research has largely focused on optimizing blade structures, with limited consideration of how front cavity clearance affects radial force and pressure pulsation. Therefore, this paper investigates the effect of front cavity clearance on the radial force and pressure pulsation of electronic water pumps through numerical simulation. The results show that under steady-state conditions, changes in the front cavity clearance significantly affect the external characteristics. Specifically, efficiency increases with the enlargement of the front cavity clearance, up to 3.5%. The variation in head is related to the flow rate: at high flow rates, it increases with the clearance, peaking at 3.5%, while at low flow rates, it decreases by up to 1.4%. The impact on impeller forces is more pronounced. Radial force decreases by up to 54.2% with larger clearance, while axial force shows the opposite trend, increasing by 202.8%. Under unsteady-state conditions, increasing the front cavity clearance dampens both radial force by up to 49.4% and pressure pulsation. The maximum 30.2% reduction in pressure pulsation. This study provides an effective tool for investigating the unsteady characteristics of electronic water pumps and offers theoretical support for suppressing radial force and pressure pulsation.