Study of BPF pressure pulsations reduction in centrifugal bladed machines using splitters

Abstract

Abstract Presence of intensive pressure pulsations and noise on blade passing frequencies is a characteristic feature of all types of centrifugal bladed machines including pumps. Under definite conditions pressure pulsations can reduce the pump reliability and life cycle. High level of tonal noise can be inappropriate due to ecological requirements. The paper is devoted to the study of application of splitters for reduction of pressure pulsations in centrifugal pumps. 2D and 3D numerical methods are used in the study. Initial computational tests were performed with a two-dimensional formulation for a centrifugal pump with a simple volute using 2D discreet vortex method for the impeller flow and 2D acoustic-vortex approach for pressure pulsations prediction. 3D unsteady flow computations of an air model of the centrifugal pump are undertaken with the impeller having splitters. Calculations of pressure pulsations show that the use of additional blades reduces the amplitude of the first harmonic of blade passing frequency by more than three times compared to the design without splitters. It correlates with flow parameters distribution along the impeller outlet diameter that has less nonuniformity and a more balanced vorticity profile. Application of splitters reduces the amplitude of pressure pulsations by a factor of 3.