Unsteady pressure-pulsation-induced severe vibration and high alternating stress can cause some unexpected results, including impeller crack and structural damage of the entire pumping system. In the present paper, a review on pressure pulsations in pumps is carried out based on the published studies. A comprehensive view on pressure pulsations from several aspects is discussed in detail. The contents of the studies include the mechanism of rotor–stator interaction; a prediction model and experimental and numerical investigations of pressure pulsations; unsteady rotating-stall-induced pressure pulsations at off-design flow rates; the relationship between pressure pulsation and the internal flow structure and cavitation; and the reduction in pressure pulsation caused by some effective approaches. It is concluded that unsteady pressure pulsation in pumps is closely associated with complex flow structures, for instance flow separation, cavitation, and rotating stall. The rotor–stator interaction mainly dominates pressure pulsation characterized by the discrete components in pressure spectrum. To reduce pressure pulsation, some effective approaches are proposed, such as increasing the rotor–stator gap, staggered blade, and blade modification. Finally, several suggestions for future works are given and discussed considering the current research. The review contributes to better understanding of pressure pulsations in centrifugal pumps, and may also benefit engineers in controlling pressure pulsations in some fields, such as pumps in nuclear reactor.

Turbulent flow generated by the intense rotor–stator interaction is detrimental to the safe running of the centrifugal pump. In order to gain more insight into unsteady velocity pulsation characteristics, this research applies the laser Doppler anemometry technique to capture velocity signals at various flow rates. Besides, pressure transducers are arranged on the model pump to sample transient pressure pulsation signals. The study paid particular attention to pulsation signals in the diffusion section of the volute. Results show that at low flow rates, a prominent hump phenomenon generated within the pump head curve, which indicates the development of rotating stall in the model pump. As noted from the spectra, the discrete blade passing frequency and impeller rotating frequency dominate the velocity and pressure spectra. Root mean square values of velocity signals increase rapidly at off-design flow rates, especially within the rotating stall region, and a similar trend is observed for pressure amplitude at the blade passing frequency. From the measuring point (P3) at the inlet of the discharge channel upstream of the volute tongue to the point (P10) at the volute outlet, pressure amplitude rises significantly. Meanwhile, the minimum point of pressure amplitude vs flow rate occurs around 0.4Φ_N, and again, the findings show differences for comparisons between measuring points in the core flow region of the volute. This resulting phenomenon can be attributed to flow patterns in the diffusion section.