Numerical Investigation on Periodic Flow Unsteadiness in a Centrifugal Pump With Volute

In this paper, the CFD simulation and flow unsteadiness analysis for a centrifugal pump with volute were carried out in whole flow passage including impeller, volute and side chamber. The periodic flow unsteadiness based on URANS equations has been quantitatively investigated in detail by defining unsteady velocity intensity, and turbulence intensity under design condition was also studied. Meanwhile, three-dimensional effect has been considered for the twisted blade channels. The time-averaged unsteady velocity intensity and time-averaged turbulence intensity were calculated by averaging the results of each grid node for entire impeller revolution period to evaluate the strength distributions of flow unsteadiness directly and comprehensively. The accumulative results of an impeller revolution can directly show the positions and strength of the flow unsteadiness and turbulence intensity in both rotor and stator domains which can be an important aspect to be considered in the centrifugal pump optimum design procedure for obtaining more stable inner flow of the pump and cutting down certain components of flow-induced vibration and noise.