Centrifugal pump performance enhancement: Effect of splitter blade and optimization

The shape of impeller blades of a centrifugal pump affects the best efficiency point (BEP), and splitter blades improve the pump performance at BEP. In this work, multiple parameters such as number of blades, length of splitter blade, splitter blade angle at hub, and wrap angle were modified to maximize head and minimize input power. The problem was solved by a numerical and experimental approach. Initially, an impeller was designed and tested in a laboratory setup. The same impeller was simulated in a computational fluid dynamics (CFD) solver, checked the accuracy of the CFD results, optimized by an in-house surrogate-based optimization code and finally the optimal designed manufactured and tested again. The mix and match of the splitter blade with the other parameters improved the pump performance i.e. head by 8.2% and overall efficiency by 3%. The improvement was due to the reduction in pressure fluctuations and uniform blade loading throughout the impeller blade span.