STUDY ON COHERENT VORTEX STRUCTURES OVER DUNE TYPE WAVY BED IN AN OPEN-CHANNEL FLOW BY DIRECT NUMERICAL SIMULATION

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Other Title
  • DNS解析による砂堆型河床上の組織的渦構造の解明

Abstract

In this study, fully developed three-dimensional turbulent flow over plural solid dune bed in an open-channel was reproduced by direct numerical simulation (DNS). Its coherent structures were also examined using time-line technique and identification of cylindrical vortex tubes.“Boil of the first kind”, which was unique to the flow field on dune-type sand wave, was numerically reproduced. It was found that kolk which causes boil of the first kind can be detected as cylindrical vortex tubes rising from the bed. It was also found that boil of first kind and kolk were generated not only from “hairpin vortices” as conventionally noted but also from “reverse hairpin vortices” with their head near the bed and cyclonic vortices at their foot.

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Details 詳細情報について

  • CRID
    1390001205170441472
  • NII Article ID
    130004043348
  • DOI
    10.2208/prohe.46.385
  • ISSN
    18849172
    09167374
  • Data Source
    • JaLC
    • Crossref
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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