{
  "id": "1110.3975",
  "version": "v1",
  "published": "2011-10-18T13:54:58.000Z",
  "updated": "2011-10-18T13:54:58.000Z",
  "title": "Hairpins et al. in Turbulent Boundary Layers",
  "authors": [
    "Philipp Schlatter",
    "Milos Ilak",
    "Mattias Chevalier",
    "Geert Brethouwer",
    "Arne V. Johansson",
    "Dan S. Henningson"
  ],
  "comment": "arXiv admin note: substantial overlap with arXiv:1010.4000",
  "categories": [
    "physics.flu-dyn"
  ],
  "abstract": "A new set of three-dimensional visualisations of a large-scale direct numerical simulations (DNS) of a turbulent boundary layer is presented. The Reynolds number ranges from $Re_\\theta=180$ to 4300, based on the momentum-loss thickness $\\theta$ and the free-stream velocity $U_\\infty$. The focus of the present fluid dynamics video is on analysing the coherent vortical structures in the boundary layer: It is clearly shown that the initial phases are dominated by coherent so-called hairpin vortices which are characteristic remainders of the laminar-turbulent transition at lower Reynolds numbers. At higher $Re$ (say $Re_\\theta>2000$), these structures are no longer seen as being dominant; the coherence is clearly lost, both in the near-wall region as well as in the outer layer of the boundary layer. Note, however, that large-scale streaks in the streamwise velocity, which have their peak energy at about half the boundary-layer thickness, are unambiguously observed. In addition to visualisation with classical three-dimensional isosurfaces, the video is also rendered using stereoscopic views using red-cyan anaglyphs.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-10-18T13:54:58.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "turbulent boundary layer",
      "large-scale direct numerical simulations",
      "reynolds number ranges",
      "fluid dynamics video",
      "lower reynolds numbers"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011arXiv1110.3975S"
    }
  }
}