{
  "abstract": "Regularized lattice Boltzmann methods improve numerical stability by projecting the nonequilibrium distribution onto its hydrodynamic second-order Hermite sector and filtering the remaining kinetic modes. We introduce a separate relaxation time for the complete complementary kinetic subspace. The resulting extended-regularized lattice Boltzmann method (E-RLBM) interpolates continuously between the Bhatnagar-Gross-Krook and regularized collision operators while retaining a two-rate implementation. A Chapman-Enskog expansion shows that the isothermal Navier-Stokes equations are recovered with kinematic viscosity $ν=c_s^2(τ-Δt/2)$, independently of the kinetic relaxation time $τ_{\\rm nh}$, whereas $τ_{\\rm nh}$ changes higher-order truncation errors. For linear transverse shear, its first effect is a fourth-derivative term whose coefficient depends on the direction of propagation relative to the lattice. This fourth-order coefficient is affine in $τ_{\\rm nh}$. For linear shear on D2Q9 and $τ_{\\rm nh}$ between $τ$ and $Δt$, it lies between the corresponding BGK and RLBM values in every propagation direction. Stability maps for the decaying Taylor-Green vortex and flow past a rectangular obstacle show that an appropriate kinetic relaxation substantially enlarges the stable parameter domain. In a Taylor-Green convergence test with consistent initialization, all three operators converge at second order, and their error differences follow the hyperviscous coefficient for diagonal shear waves: the E-RLBM error is about 6% above the BGK error and about 40% below the RLBM error; in a double shear layer at Re = 80000, the E-RLBM follows the RLBM convergence curve. The proposed collision operator therefore provides a low-cost means of controlling nonhydrodynamic modes without introducing a full multiple-relaxation-time basis.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.31072",
  "author_total": 2,
  "authors": [
    {
      "name": "Luís Orlando Emerich dos Santos"
    },
    {
      "name": "Diogo Nardelli Siebert"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7tted8napdpb0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.31072",
  "fulltext_url": null,
  "id": "7tted8napdpb0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.31072",
  "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.comp-ph"
    ],
    [
      "arxiv",
      "physics.flu-dyn"
    ],
    [
      "openalex",
      "2206|Lattice Boltzmann Simulation Studies"
    ]
  ],
  "openalex": "W7223285233",
  "pdf_url": "https://arxiv.org/pdf/2610.31072",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7tted8napdpb0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:34Z",
      "native_id": "2610.31072",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.31072"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.comp-ph",
      "subfield": "computational"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.flu-dyn",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "Extended-regularized lattice Boltzmann method",
  "title_text": "Extended-regularized lattice Boltzmann method",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:34Z",
  "url": "https://research.draconitic.com/paper/7tted8napdpb0",
  "venue": "arXiv",
  "versions": []
}