{
  "abstract": "Achieving sufficient near-wall resolution remains challenging for wall-bounded turbulence simulations using weakly compressible smoothed particle hydrodynamics (WCSPH), as local particle refinement imposes restrictive time-step requirements. This work proposes a multi-scale near-wall approach within the Reynolds-averaged Navier--Stokes (RANS) framework to improve near-wall predictions without refining the SPH particle distribution. A local one-dimensional sublayer solver based on the simplified steady $k$--$ω$ equations is coupled with each wall-adjacent fluid particle. A local flow-rate constraint and a friction-velocity-based iteration scheme are developed to close and solve the sublayer system, while a two-way shear-stress coupling with local feedback improves consistency between the two scales. The proposed approach is evaluated using turbulent straight-channel flows over a wide range of Reynolds numbers and a wavy-channel flow involving separation and recirculation. The results demonstrate improved near-wall velocity, turbulent kinetic energy and friction-coefficient predictions, satisfactory convergence, and good agreement with reference solutions. In particular, the approach improves the convergence of near-wall predictions where conventional wall treatments struggle to provide consistent results, and agrees closely with reference solutions at Reynolds numbers as high as $8.0 \\times 10^{7}$ without near-wall particle refinement. For separated flow, convergence comparable to that of locally refined finite-volume simulations is obtained using an approximately uniform particle distribution. These improvements are achieved with limited computational overhead, supporting the application of particle-based methods to engineering flows involving wall-bounded turbulence.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.21736",
  "author_total": 3,
  "authors": [
    {
      "name": "Feng Wang"
    },
    {
      "name": "Nikolaus Adams"
    },
    {
      "name": "Xiangyu Hu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4tyzn6p8twz3b.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.21736",
  "fulltext_url": null,
  "id": "4tyzn6p8twz3b",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.21736",
  "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 Simulations and Interactions"
    ]
  ],
  "openalex": "W7213944043",
  "pdf_url": "https://arxiv.org/pdf/2609.21736",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-18",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4tyzn6p8twz3b.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:03Z",
      "native_id": "2609.21736",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.21736"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.flu-dyn",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "A multi-scale approach for wall-bounded WCSPH--RANS simulations",
  "title_text": "A multi-scale approach for wall-bounded WCSPH--RANS simulations",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:03Z",
  "url": "https://research.draconitic.com/paper/4tyzn6p8twz3b",
  "venue": "arXiv",
  "versions": []
}