Clocking effect of relative position matching on the hydrodynamic and flow-induced noise characteristics in a centrifugal pump

• RPM between rotating and stationary blade can cause clocking effect. • The absolute value of Ce is negatively correlated with pump performance. • The clocking effect is not the only parameter that determines the performance. • The clocking effect improves noise performance by changing the unsteady surface pressure. This paper investigates the influence of the clocking effect caused by the relative position matching(RPM) between the rotating and stationary blades in a single-stage centrifugal pump. Numerical simulations are used to study the hydrodynamic performance and flow-induced noise characteristics under different speed configurations. Acoustic predictions are made using the Ffowcs Williams-Hawkings (FW-H) analogy. Experimental validations are carried out for validation. The results indicates that the clocking effect caused by RPM can improve pump hydrodynamic performance and noise characteristics. A non-dimensional parameter describing the clocking effect caused by RPM is proposed, which absolute value shows a significant negative correlation with the pump head and sound pressure. The variation of hydrodynamic performance and noise characteristics among the different C e are compared, suggesting that the C e is not the only factor and is also affected by the blade tilt angle. The analysis of the flow field indicates that the clocking effect primarily enhances noise reduction by improving the transmission characteristics of pressure fluctuation, and then improves the unsteady surface pressure distribution on the wall of the volute. The above results demonstrate that it is able to achieve the effect of increasing the head and reducing the noise by adjusting the RPM.