Multi-objective optimization for suppressing flow-induced vibration in a centrifugal pump impeller

To suppress the flow-induced vibration of a single-stage single-suction centrifugal pump (rated head 5 m, flow rate 30 m 3 /h, rotational speed 1000 r/min), the key impeller parameters were taken as design variables and screened via the parameter sensitivity analysis method in this study. The internal flow field was solved using the Reynolds-Averaged Navier–Stokes (RANS) approach with the SST k–ω turbulence model, implemented in the commercial CFD code ANSYS Fluent. With pump efficiency and the sample standard deviation of circumferential tangential velocity uniformity at all nodes of the impeller outlet set as the optimization objectives, and pump head as the constraint condition, the Kriging surrogate model combined with the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was adopted to conduct the optimal design of the impeller structure. The results show that the head and efficiency of the optimized pump are increased by 10.8% and 2.7%, respectively. The pressure pulsation amplitudes associated with the blade-passing frequency (BPF) at the volute tongue are significantly reduced, with a 36.1% decrease at the volute tongue and a 22% decrease inside the volute, which effectively mitigates the rotor-stator interaction (RSI). Comparisons of the internal flow fields confirm the suppressed secondary flows, reduced turbulent kinetic energy, weakened jet-wake effects, and improved unsteady performance of the optimized pump, thus verifying the feasibility and effectiveness of the proposed optimization strategy.