Computational Analysis and Design Improvement of an Industrial Centrifugal Pump with Experimental Validation

Centrifugal pumps are one of the work horses in any process industries. Over the past few years, efforts to increase the performance of the centrifugal pump by various means have been ongoing. The performance of centrifugal pump is significantly affected by the path the fluid traverses along the geometry of blade and casing of the pump. Visualization of the fluid flow is difficult to comprehend. In the present work, commercial computational fluid dynamics (CFD) code, ANSYS CFX package is used to numerically simulate the 3D flow of water inside an industrial centrifugal pump. The effect of changing the volute geometry at regions of interest is studied. Steady-state analysis is performed using shear stress transport (SST) turbulence model using mixing plane interface between moving and stationary zones of the pump. Further, transient simulation using sliding mesh interface was carried out using results obtained from steady analysis as initial conditions. From the above results, recirculation was observed in the casing and minor losses near the neck region of the pump. Based on the results of transient simulation, the casing area was reduced at 2 regions by 4%, 8% and 12% to understand its effect on recirculation and minor losses. The results of transient analysis on the casing geometry showed that 8% reduction in area improved the pump efficiency by 4.85% at the design flow rate of 111.11 kg/s. The efficiency improvement of the pump is attributed to the reduction in recirculation and minor losses. The improvements in the efficiency were validated by experimental results. The experimental results showed an improvement of efficiency by 4.62%.