{
  "id": "1810.06732",
  "version": "v1",
  "published": "2018-10-15T22:27:00.000Z",
  "updated": "2018-10-15T22:27:00.000Z",
  "title": "On the small-scale structure of turbulence and its impact on the pressure field",
  "authors": [
    "Dimitar G. Vlaykov",
    "Michael Wilczek"
  ],
  "comment": "Accepted for publication by the Journal of Fluid Mechanics",
  "categories": [
    "physics.flu-dyn"
  ],
  "abstract": "Understanding the small-scale structure of incompressible turbulence and its implications for the non-local pressure field is one of the fundamental challenges in fluid mechanics. Intense velocity gradient structures tend to cluster on a range of scales which affects the pressure through a Poisson equation. Here we present a quantitative investigation of the spatial distribution of these structures conditional on their intensity for Taylor-based Reynolds numbers in the range [160, 380]. We find that the correlation length of $-\\mathrm{Tr} \\mathbf{A}^2/2$, the second invariant of the velocity gradient, is proportional to the Kolmogorov scale. It also is a good indicator for the spatial localization of intense enstrophy and strain-dominated regions, as well as the separation between them. We describe and quantify the differences in the two-point statistics of these regions and the impact they have on the non-locality of the pressure field as a function of the intensity of the regions. Specifically, across the examined range of Reynolds numbers, the pressure in strong rotation-dominated regions is governed by a dissipation-scale neighbourhood. In strong strain-dominated regions, on the other hand, it is determined primarily by a larger neighbourhood reaching inertial scales.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-10-15T22:27:00.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "76F05",
      "76F02"
    ],
    "keywords": [
      "pressure field",
      "small-scale structure",
      "turbulence",
      "intense velocity gradient structures tend",
      "reynolds numbers"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}