Abstract：In order to study the rules of pressure fluctuation and flow-noise change under different flow conditions in a centrifugal pump,and to find the relationship between pressure fluctuation and flow-noise,the frequency spectra of pressure signals and noise signals collected by high-frequency pressure transducer and hydrophone located at the pump discharge have been obtained with experimental method.The results show that the blade passage frequency dominates for all operating conditions,which manifests that the fluid-structure interaction between the rotating blades and the volute tongue may be the primary source of pressure fluctuation and noise generation.The flow noise frequency spectra has evident peak at the second multiple of the rotating frequency and 224.8 Hz,which is caused by the number of blade and the volute vibration.The frequency spectra of pressure fluctuation and flow noise are unanimous for small flow,and the flow noise may be predicted with the pressure fluctuation.But with the increase of flow,the high frequencies above 500 Hz and the blade passage frequency appear in the flow noise frequency spectra,which implies that the flow noise is partly caused by cavitation and turbulence,except pressure fluctuation for these operating conditions.
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