Abstract
The development of low-noise pumps is essential to design quiet fluid delivery systems. Due to the complicated internal flow, the flow-induced noise characteristics of high-speed centrifugal pumps have not been well understood. Taking engine cooling pumps as an example model, experimental measurements are performed in a semi-anechoic room and a CFD/CFA calculation method is proposed to study the fluid-borne noise and radiated noise characteristics. In the speed range of 5000–6750 r/min, both the pump head and the dimensionless radiated noise characteristics conform to similar laws, and the highest efficiency point pump presents the lowest noise level. Consistent with the experimental results, the predicted radiated noise of the model pump presents dipole characteristics at the required flow rate condition. Moreover, the spectrum of fluid borne noise at pump outlet shows broadband characteristics but with obvious discrete peaks, which are not only related to the fluid pressure pulsation characteristics (6f0 and the multiple) at the low-frequency region, but also to the frequency of the structural mode (3000–6000 Hz region). Rotor-stator interaction of the pump flow field between the impeller and volute is the main reason of flow-induced noise; unstable flow also contributes to the broadband components in the noise spectrum.
Highlights
Pumps are widely used in social and economic life, such as high building water supply, engine cooling, chemical process, nuclear power, and so on, most of which are centrifugal pumps
Where p1 and p2 imply the inlet pressure and outlet pressure, respectively; v1, v2 denote the average velocities of the inlet and outlet section, respectively; z1, z2 are the heights at the inlet and outlet center section of the model pump to the reference horizontal plane; ρ denotes the fluid density; g denotes the standard acceleration of gravity; Pe is the shaft power calculated by the input power and motor radiated noise field, two sets of microphone sensors are arranged, respectively, in the direction perpendicular to the inlet tube and 45 °oblique to the inlet tube
It can be seen that the dimensionless head and efficiency performance curves at different rotational speeds have high similarity, which means the internal flow in the pump follows a similar law
Summary
Pumps are widely used in social and economic life, such as high building water supply, engine cooling, chemical process, nuclear power, and so on, most of which are centrifugal pumps. Si et al [17,18] proposed a numerical calculation method of flow-induced noise in a centrifugal pump combining CFD and CA (computational acoustics). Accurate flow noise prediction based on analogy theory is the development trend, but numerical methods that consider both fluid-borne noise and radiated noise still need development at present. A CFD/CFA (computational fluid dynamics/computational fluid acoustic) method is proposed to calculate the fluid-borne noise and flow-induced radiated noise of high-speed centrifugal pumps based on Lighthill’s acoustic analogy theory. The numerical flow-induced noise characteristics of the high-speed centrifugal pumps under the required working conditions are studied .
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
