Investigation of unsteady pressure fluctuations and methods for its suppression for a double suction centrifugal pump

Double suction centrifugal pumps find their usage in a variety of applications because of their ability to deliver good performance at higher flowrates and heads. The main issue with these devices is the occurrence of large pressure pulsations which cause noise, vibration, and unstable operation. The present work makes an effort using steady and unsteady computational fluid dynamics (CFD) approach to minimize these pulsations and also to improve the hydraulic performance of the considered pump. The CFD methodology and obtained results were validated by the experimental data to ensure reliability of the study. Fast Fourier Transform (FFT) analysis was performed to calculate the amplitude of these pressure pulsations. A parametric study was undertaken to find the effect of impeller stagger angles in reducing these pulsations and finding the most desirable stagger angle. Then, the performance of reference non-staggered impeller design was evaluated with the use of split volute arrangement and its comparison was done with the staggered impeller design. Finally, a combination of staggered impeller design with the split volute arrangement was tested to find its utility in suppressing pressure pulsations. It was observed that the best hydraulic performance could be obtained by the staggered 30 degrees design with reduced pulsations; however, the least pressure pulsations were delivered by the combination of staggered 30 degrees design with the split volute. The use of CFD helped in better visualization of the inherent flow physics associated with these designs. (C) 2022 Elsevier Ltd. All rights reserved.