Study on the influence of the splitter blade length on radial and axial force of a centrifugal pump

To enhance the operational stability of centrifugal pumps, this study investigates the influence of splitter blade length on the axial and radial forces of centrifugal pumps. Using the SST k-ω turbulence model and experimental research, the external characteristics, axial force, radial force, and time-frequency characteristics of pressure pulsation were compared among impellers without splitter blades and those with splitter blades of two different lengths. The results show that impellers with a conventional structure achieve higher efficiency near the design operating point. However, under low-flow conditions, the rectifying effect of splitter blades allows impellers with splitter blades to achieve higher efficiency. For impellers with splitter blades, the axial force shows a periodic behavior, presenting two peak values — one large and one small — within each cycle. The addition of splitter blades shifts the radial force acting on the impeller to one side, requiring an increase in the support strength and stiffness of the rotor system. Furthermore, splitter blades influence the pressure pulsation at the impeller's inlet and outlet, the original impeller has an additional pulsation energy at 145 Hz but the splitter blades are different. Thus, an impeller with splitter blades can reduce the frequency pulsation and optimizing flow conditions. This study provides valuable theoretical insights and data support for the hydraulic structural optimization of centrifugal pumps.