{
  "abstract": "Finger-type convection in double-diffusive instability (DDI) controls mixing and scalar transport in many stratified flows, yet a quantitative, finger-resolved description of the transient growth, transport, and saturation pathways has been limited. Here, finger-type DDI is analyzed in a sealed-surface laboratory facility using synchronized planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) at fixed thermal contrast $ΔT=5^\\circ$C and three salinity contrasts, $ΔS=350$, 450, and 550 ppm, complemented by a matched high-resolution three-dimensional DNS. A systematic fingertip detection and tracking framework generates ensemble growth curves. Fingertip growth follows a sequence of three stages (acceleration, quasi-steady propagation, and decay). The peak growth rates increase monotonically with $ΔS$, and nondimensional fingertip-height histories collapse onto a common trend. The peak growth rates are reproduced by DNS and agree with linear stability analysis, establishing experiment--DNS--theory consistency in the intermediate regime. The mixed-material area increases with time, initially following a common nondimensional trend before transitioning to $ΔS$-dependent interaction and breakdown. Finger-scale measurements reveal the formation of a symmetric vortex ring at the fingertips for $ΔS=450$ ppm, inducing vertical-aligned transport. At $ΔS=550$ ppm the roll-up becomes asymmetric: stronger buoyancy amplifies shear, destabilizes the vortex ring, and produces a zig-zag/lateral-drift mode that enhances the lateral transport. Finally, the evolution of the buoyancy anomaly links the growth-rate phases to a time-dependent force balance in which increasing buoyancy drives acceleration, shear-induced resistance regulates quasi-steady propagation, and dilution with top-boundary influence yields late-stage fingertip deceleration.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.00335",
  "author_total": 4,
  "authors": [
    {
      "name": "Mohammad Mohaghar"
    },
    {
      "name": "Anirban Bhattacharjee"
    },
    {
      "name": "Suhas S. Jain"
    },
    {
      "name": "Donald R. Webster"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/evrktstjhz6he.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.00335",
  "fulltext_url": null,
  "id": "evrktstjhz6he",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.00335",
  "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": "W7160134602",
  "pdf_url": "https://arxiv.org/pdf/2605.00335",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/evrktstjhz6he.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:14Z",
      "native_id": "2605.00335",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.00335"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.flu-dyn",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "Dynamics of finger-type convection in double-diffusive instability",
  "title_text": "Dynamics of finger-type convection in double-diffusive instability",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:14Z",
  "url": "https://research.draconitic.com/paper/evrktstjhz6he",
  "venue": "arXiv",
  "versions": []
}