Investigation on the Changing Characteristics of Flow-Induced Noise in a Centrifugal Pump

Centrifugal pumps are widely used in engineering for a variety of applications. A known drawback of these devices is the high-level noise generated during operations, which can affect their stability and adversely influence the entire working environment. By combining the Powell vortex sound theory, numerical simulations and experimental measurements, this research explores the trends of variation and the corresponding underlying mechanisms for the flow-induced noise at various locations and under different operating conditions. It is shown that the total sound source intensity (TSSI) and total sound pressure level (TSPL) in the impeller, in the region between the inlet to the outlet and along the circumferential extension of the volute, are much higher than those at pump inlet and outlet. Additionally, under various rotational speeds with the design flow rate (Condition 1), the TSSI and TSPL at pump inlet and outlet are higher than those obtained with the opening of the valve kept unchanged (Condition 2); vice versa when these two parameters are evaluated at various locations in the impeller and the volute under the Condition 2, they exceed the equivalent values obtained for the other Condition 1.