{
  "id": "1704.08368",
  "version": "v1",
  "published": "2017-04-26T22:31:13.000Z",
  "updated": "2017-04-26T22:31:13.000Z",
  "title": "Surface-sampled simulations of turbulent flow at high Reynolds number",
  "authors": [
    "Neil D. Sandham",
    "Roderick Johnstone",
    "Christian T. Jacobs"
  ],
  "comment": "Author accepted version. Accepted for publication in the International Journal for Numerical Methods in Fluids on 26 April 2017",
  "categories": [
    "physics.flu-dyn",
    "cs.CE",
    "physics.comp-ph"
  ],
  "abstract": "A new approach to turbulence simulation, based on a combination of large-eddy simulation (LES) for the whole flow and an array of non-space-filling quasi-direct numerical simulations (QDNS), which sample the response of near-wall turbulence to large-scale forcing, is proposed and evaluated. The technique overcomes some of the cost limitations of turbulence simulation, since the main flow is treated with a coarse-grid LES, with the equivalent of wall functions supplied by the near-wall sampled QDNS. Two cases are tested, at friction Reynolds number Re$_\\tau$=4200 and 20,000. The total grid node count for the first case is less than half a million and less than two million for the second case, with the calculations only requiring a desktop computer. A good agreement with published DNS is found at Re$_\\tau$=4200, both in terms of the mean velocity profile and the streamwise velocity fluctuation statistics, which correctly show a substantial increase in near-wall turbulence levels due to a modulation of near-wall streaks by large-scale structures. The trend continues at Re$_\\tau$=20,000, in agreement with experiment, which represents one of the major achievements of the new approach. A number of detailed aspects of the model, including numerical resolution, LES-QDNS coupling strategy and sub-grid model are explored. A low level of grid sensitivity is demonstrated for both the QDNS and LES aspects. Since the method does not assume a law of the wall, it can in principle be applied to flows that are out of equilibrium.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-04-26T22:31:13.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high reynolds number",
      "turbulent flow",
      "surface-sampled simulations",
      "turbulence simulation",
      "total grid node count"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}