{
  "abstract": "Turbulence approaching an aerofoil leading edge is strained and blocked in the final few nose radii. Rapid-distortion theory assumes that the pre-impact field is a linear image of the upstream turbulence; we test that assumption directly. Grid turbulence is computed over a NACA~0012 aerofoil and sampled on three congruent surfaces around the nose, giving the cross-spectral tensor between upstream and pre-impact stations. Relative to a no-aerofoil control, the linearity spectrum falls by a factor of three already at the energy-containing scales ($κ= k\\,r_{\\mathrm{LE}} \\approx 0.3$), showing that a substantial part of the pre-impact turbulence is generated locally rather than inherited. The same location appears in physical space: the anisotropy invariant $III_b$ changes sign from prolate to oblate within the last few per cent of chord, departing the plane-strain rapid-distortion prediction. The change is produced by pressure--strain redistribution, which drains the strain-amplified wall-normal stress into the other components; the term is absent in the control and becomes active once the accumulated strain is rapid. Across a fourteen-fold range of nose radius the sign change occurs at $x \\approx -1.5\\,r_{\\mathrm{LE}}$ and the generated turbulence is spanwise-dominated. At second order the mapping remains usable: when inserted into a standard Amiet prediction it improves agreement with measured leading-edge noise, and the same coefficients transfer to independent published cases when only nose radius and free-stream speed are supplied.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.16709",
  "author_total": 4,
  "authors": [
    {
      "name": "Sparsh Sharma"
    },
    {
      "name": "Malav Soni"
    },
    {
      "name": "Alexandre Suryadi"
    },
    {
      "name": "Michaela Herr"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4ghcd38na1kjg.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.16709",
  "fulltext_url": null,
  "id": "4ghcd38na1kjg",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.16709",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.flu-dyn"
    ],
    [
      "openalex",
      "2206|Fluid Dynamics and Turbulent Flows"
    ]
  ],
  "openalex": "W7213394828",
  "pdf_url": "https://arxiv.org/pdf/2609.16709",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4ghcd38na1kjg.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:41Z",
      "native_id": "2609.16709",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.16709"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.flu-dyn",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "Turbulence at an aerofoil leading edge: the linearity boundary and its generation mechanism",
  "title_text": "Turbulence at an aerofoil leading edge: the linearity boundary and its generation mechanism",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:41Z",
  "url": "https://research.draconitic.com/paper/4ghcd38na1kjg",
  "venue": "arXiv",
  "versions": []
}