Study on the inner flow mechanisms and unsteady force distribution of side channel pump

Abstract

Stability dynamics in pumps is a key problematic issue which needs to be critically looked at. For instance, in side channel pump, pressure fluctuations and unsteady forces characteristics are inevitable in the clearances and this strongly affects the flow and pressure stability. Therefore, the research work herein seeks to numerically investigate the pressure fluctuation intensity in the clearances and characterize the axial and radial forces distributions around the impeller under different blade suction angles. Three impeller schemes 1, 2, and 3 are modeled with blade suction angles 10°, 20°, and 30°, respectively. Based on the reliable standard SST k-ω turbulent flow model, the unsteady flow state of the side channel pump was obtained by numerical simulation and further verified by experiment results. Variations in amplitude and frequency at different monitoring points in the clearances were observed in both time and frequency domain for each impeller scheme. The findings elucidate that pressure fluctuation intensity in the clearances is significantly different for all the impeller schemes. Obvious asymmetrical distribution of fluctuation magnitudes was noticeable in the axial and radial clearance. Generally, the amplitude of pressure fluctuation intensity of impeller scheme 1 and 2 is substantially reduced compared to impeller scheme 3. Also, impeller scheme 1 exerts the smallest magnitude of axial and radial force. However, when the pump operates under impeller scheme 3, the amplitude of the forces increases significantly. This study provides a solid foundation for the reduction of pressure fluctuations, vibration, and noise performance in side channel pumps.