Optimization of a centrifugal pump to improve hydraulic efficiency and reduce hydro-induced vibration

To improve hydraulic efficiency and reduce hydro-induced vibration of centrifugal pump, this paper proposes an optimization method based on Kriging surrogate model and optimal searching algorithm (NSGA-II) with a validated numerical simulation. The distributions of blade thickness and blade angles on the hub and shroud surface along streamwise are controlled by spline curves with several points. In order to improve the efficiency of optimization process, a steady indicator is introduced to characterize the intensity of unsteady pressure pulsation and numerical simulation of four group pumps are conducted to verify its reliability. Optimization results show that the hydraulic efficiency is increased by 4.19% and the pressure pulsation amplitude at blade passing frequency (fBPF) is significantly reduced at design condition after optimization, which is ultimately reflected in a 62.59% reduction in vibration acceleration at fBPF. Besides, the internal flow analysis is conducted to illustrate the effects of impeller modification. Results show that the unsteady flow structure in the pump is reduced due to the blade profile optimization, which ultimately leads to the high comprehensive performance.