Numerical Estimation and Validation of Pressure Pulsation in Centrifugal Pump Discharge Pipes

Pressure pulsation is inherently present in all centrifugal pumps because of the rotor–stator interaction of impeller and volute. But its higher value may cause trouble in the performance and operation of the centrifugal pump. The experimental method traditionally investigates pressure pulsation, but the advancements in numerical and CFD methods allow us to explore this effect easily. The Tetra/Mixed grid method was used for meshing in ICEM CFD to investigate the transient variation of pressure pulsation. The analysis involves a parametric study in which parameters related to the impact of the cutwater gap (Gap-B) and variable frequency drives on pressure pulsation. The four Gap-B% and four pump speeds were used for analysis of pressure pulsation. Total 8 monitor points were placed in discharge pipes including point at half and quarter wavelength to measure pulsation on the discharge side. From analysis it was observed that Gap-B% had a greater impact on pressure pulsation and an increase in speed also results in significant pulsation. A non-dimensional number was used to compare the results with the experimental method and the results were found to be comparable. Gap-B of 9% and above was found to be optimal since pressure pulsation was less.