{
  "abstract": "Multiscale gas flows often span a wide range of Knudsen numbers, from near-continuum to highly rarefied and strongly nonequilibrium conditions. Such flows require kinetic solvers that remain accurate across these regimes. The discrete unified gas-kinetic scheme (DUGKS) provides a unified description, but its computational cost and memory consumption are dominated by the size of the discrete velocity space. To alleviate this bottleneck, this work develops the multi-level velocity-space adaptive discrete unified gas-kinetic scheme (MLVS-DUGKS), reducing velocity-space redundancy while preserving accuracy and conservation. The method identifies the velocity-space requirements of individual physical cells from their distribution functions and groups these requirements into a small number of shared representative velocity spaces. This organization retains sensitivity to different local flow states without constructing an independent velocity space for every physical cell. A linear moment-constrained correction is incorporated to maintain discrete compatibility and conservative data transfer between representative spaces. Benchmark simulations spanning near-continuum to highly rarefied regimes show close agreement with the uniform-velocity-space DUGKS (UVS-DUGKS). For the cylinder and two-cavity problems, the average number of discrete velocity points is reduced by approximately one order of magnitude, yielding speedups of $7.00$--$7.93$ and GPU-memory reductions by factors of $6.73$--$7.49$. As a result, the MLVS-DUGKS provides an efficient tool for the simulation of multiscale nonequilibrium gas flows.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.35258",
  "author_total": 5,
  "authors": [
    {
      "name": "Weijie Ren"
    },
    {
      "name": "Hang Yu"
    },
    {
      "name": "Zhengyu Tian"
    },
    {
      "name": "Wenjia Xie"
    },
    {
      "name": "XiaoQiang Fan"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6a6scey8q5b7t.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.35258",
  "fulltext_url": null,
  "id": "6a6scey8q5b7t",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.35258",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.flu-dyn"
    ],
    [
      "openalex",
      "2604|Gas Dynamics and Kinetic Theory"
    ]
  ],
  "openalex": "W7214733999",
  "pdf_url": "https://arxiv.org/pdf/2609.35258",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6a6scey8q5b7t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:36:22Z",
      "native_id": "2609.35258",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.35258"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.flu-dyn",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "A Conservative Multi-Level Adaptive Velocity-Space Method for the Discrete Unified Gas-Kinetic Scheme",
  "title_text": "A Conservative Multi-Level Adaptive Velocity-Space Method for the Discrete Unified Gas-Kinetic Scheme",
  "type": "preprint",
  "updated_at": "2026-11-01T12:20:44Z",
  "url": "https://research.draconitic.com/paper/6a6scey8q5b7t",
  "venue": "arXiv",
  "versions": []
}