Effect of the number of blades on diffuser unsteady loss of centrifugal pump

Akihito Ueda*, Tomoki Takeda, Daisuke Sugiyama, Kazuyoshi Miyagawa

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

1 Citation (Scopus)


In recent years, an unshrouded impeller is being developed for rocket turbopumps to reduce production costs and disk friction losses. However, the internal flow structure in a diffuser influenced by an impeller has not been clarified yet. In this study, we focused on the investigation of unsteady flow in turbopumps with unshrouded impellers and vaned diffusers by experiments and CFD. Furthermore, we investigated the effect of changing the number of blades of the impeller and diffuser on the unsteady losses in the diffuser. First, we measured the static pressure at the shroud side in the impeller and the velocity at the diffuser inlet and outlet. Second, we confirmed the accuracy of the CFD by comparing CFD results with experimental results. Third, we investigated unsteady losses in diffusers by CFD. We could confirm increased entropy at the suction surface and shroud side because of the tip leakage and the vortex. Finally, we changed the number of impeller blades or diffuser blades. In conclusion, the loss region at the suction surface and the high-pressure region at pressure surface in the unshrouded impeller were mixed and caused unsteady losses through the diffuser. And diffuser efficiency decreased because channel width in diffuser became narrower by the number of diffuser blades increasing.

Original languageEnglish
Article number012052
JournalJournal of Physics: Conference Series
Issue number1
Publication statusPublished - 2022 May 6
Event16th Asian International Conference on Fluid Machinery, AICFM 2021 - Virtual, Online
Duration: 2021 Sept 132021 Sept 15

ASJC Scopus subject areas

  • Physics and Astronomy(all)


Dive into the research topics of 'Effect of the number of blades on diffuser unsteady loss of centrifugal pump'. Together they form a unique fingerprint.

Cite this