Unsteady behavior of diffuser stall in a centrifugal compressor with vaned diffuser

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    4 Citations (Scopus)

    Abstract

    In this study, the unsteady behavior of a diffuser rotating stall in a centrifugal compressor with a vaned diffuser was investigated through experiments and numerical analyses. From the casing static pressure measurements, it was determined that the diffuser stall propagated at 25% of impeller rotational speed in the vaneless space. The numerical results revealed the presence of a typical vortical structure on the diffuser's leading edge. Under partial flow condition, a tornado-Type vortex was generated on the diffuser's leading edge. Furthermore, a longitudinal vortex at the shroud/suction surface corner (i.e., leading edge vortex (LEV)) was induced by the rolling-up flow on the diffuser suction surface. As the velocity was decreased, the development of the tornado-Type vortex and LEV forms a substantial flow blockage within the diffuser passages. Furthermore, the diffuser stall cell was caused by the systematic vortical structure which consisted of the tornado-Type vortex, LEV, and vortex in the throat area of diffuser passages. In addition to this, the developed LEV interacted with the next diffuser leading edge and formed the throat area blockage with the passage of time. Then, the tornado-Type vortex and LEV developed by the throat area blockage and diffuser stall cell, which was caused by the systematic vortical structure, propagated to the succeeding diffuser vane. Therefore, the diffuser stall in the centrifugal compressor was caused by the evolution of the tornado-Type vortex and LEV.

    Original languageEnglish
    Title of host publicationTurbomachinery
    PublisherAmerican Society of Mechanical Engineers (ASME)
    Volume2D-2017
    ISBN (Electronic)9780791850817
    DOIs
    Publication statusPublished - 2017
    EventASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT 2017 - Charlotte, United States
    Duration: 2017 Jun 262017 Jun 30

    Other

    OtherASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT 2017
    CountryUnited States
    CityCharlotte
    Period17/6/2617/6/30

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    ASJC Scopus subject areas

    • Engineering(all)

    Cite this

    Fujisawa, N., Ema, D., & Ota, Y. (2017). Unsteady behavior of diffuser stall in a centrifugal compressor with vaned diffuser. In Turbomachinery (Vol. 2D-2017). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/GT2017-63400