Numerical study on the hydrodynamic characteristics of multi-stage centrifugal pumps influenced by impeller-guide vane clocking effect

A high-speed multi-stage centrifugal pump building upon a transient investigation into the hydrodynamic characteristics, is conducted for 16 sets of clocking positions. The most significance of the pump head has a maximum increase of 3.6% at 0.8Qd. Phase differences emerge in the pressure pulsations at the impeller-guide vane gaps across stages. It results in waveform distortions that are primarily influenced by impeller clocking effects. Innovative average energy flux density analysis shows that impeller-guide vane clocking positions have the greatest influence on pressure pulsations near their gaps. The cumulative propagation of pressure pulsations has a relatively minor effect on fluid domains. Worst stability is observed when impellers rotated with a 3/4 maximum offset angle and guide vane positions remain unchanged. The best clocking position solution was adapted in a prototype pump for performance and operational stability measuring, achieving an efficiency of 53.67% and 1 mm/s vibration. This paper aims to provide valuable insights for enhancing the energy efficiency and operational safety of multi-stage pumps, offering beneficial guidance for engineering practices within the field of fluid machinery applications.