Multi-objective optimization and performance analysis of the splitter blades in a multiphase pump

Helical axial-flow multiphase pumps are core devices for developing deep-sea oil and gas, but the complex two-phase flow inside such pumps affects their transport stability. As reported here, for enhanced flow characteristics, splitter blades were added at the noncoincidence area of the impeller tail by using a multi-objective optimization method, and their impact on the pump performance was explored in comparison with the original model. The results indicate that Gaussian process regression combined with particle swarm optimization accurately predicts the pump external characteristics. Under an inlet gas volume fraction of 30%, the optimized model increases the head coefficient by 22.2% without reducing efficiency. Although splitter blades enhance the impeller tail, they intensify gas-phase accumulation at the tail. The optimized model promotes more-uniform two-phase flow in the channels, with the axial velocity uniformity of the gas phase and liquid phase improving by 15.1% and 9.5% and the average velocity angle increasing by 12.3° and 8.3° under an inlet gas volume fraction of 30%.