Investigation of interaction between tip leakage flow generated by unshrouded impeller and diffuser internal flow

Asuma Ichinose, Norio Kimura Mamiko Yoshimura, Tomoyuki Hayashi, Kazuyoshi Miyagawa

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    1 Citation (Scopus)

    Abstract

    Rocket turbo pumps and industrial pumps such as water feed pumps are required to work under high pressure conditions, therefore low specific speed pumps are needed in spite of high rotational speed. In recent years, unshrouded impellers were used because of easy manufacturing and cost reduction. However, when low specific speed unshrouded impellers are used in such conditions, complex tip leakage flow occur and decrease impeller performance. In addition, splitter blades are often used, the internal flow becomes even more complicated. Therefore, such the internal flow of the unshrouded impeller must be clarified. In this research, we have studied such a centrifugal pump, and we have analyzed the internal flow using experiments and CFD (Computational Fluid Dynamics) simulations. The experimental verification was carried out by measuring the total pressure distribution on the outlet of the impeller and the diffuser. The unsteady static pressure distribution at the shroud side of the impeller was measured to confirm pump performance. We used two types of CFD simulation to evaluate the internal flow in detail. In the first CFD simulation, the unsteady internal flow of an impeller was evaluated by carrying out DES (Detached Eddy Simulation) with a periodic boundary condition that does not contain the diffuser. In the second CFD simulation, interaction between the impeller leakage flow and the diffuser internal flow was evaluated by DES with the whole impeller and diffuser. From the experimental verification and CFD simulation, it was confirmed that a large-scale vortex structure caused by the tip leakage flow and the secondary flow was observed in the impeller blade-to-blade. And the influence of the impeller leakage flow on the diffuser internal flow and the diffuser performance was evaluated. From the above studies, it was confirmed that the tip leakage flow has a large influence on the impeller internal flow and the diffuser performance.

    Original languageEnglish
    Title of host publicationFluid Machinery; Erosion, Slurry, Sedimentation; Experimental, Multiscale, and Numerical Methods for Multiphase Flows; Gas-Liquid, Gas-Solid, and Liquid-Solid Flows; Performance of Multiphase Flow Systems; Micro/Nano-Fluidics
    PublisherAmerican Society of Mechanical Engineers (ASME)
    Volume3
    ISBN (Electronic)9780791851579
    DOIs
    Publication statusPublished - 2018 Jan 1
    EventASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting, FEDSM 2018 - Montreal, Canada
    Duration: 2018 Jul 152018 Jul 20

    Other

    OtherASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting, FEDSM 2018
    CountryCanada
    CityMontreal
    Period18/7/1518/7/20

    ASJC Scopus subject areas

    • Mechanical Engineering

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  • Cite this

    Ichinose, A., Yoshimura, N. K. M., Hayashi, T., & Miyagawa, K. (2018). Investigation of interaction between tip leakage flow generated by unshrouded impeller and diffuser internal flow. In Fluid Machinery; Erosion, Slurry, Sedimentation; Experimental, Multiscale, and Numerical Methods for Multiphase Flows; Gas-Liquid, Gas-Solid, and Liquid-Solid Flows; Performance of Multiphase Flow Systems; Micro/Nano-Fluidics (Vol. 3). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/FEDSM2018-83502