{
  "abstract": "Oscillating-foil-based energy harvesters have demonstrated strong potential for low-speed hydrokinetic energy extraction; however, the actuator-level mechanical energy balance associated with prescribed pitching motion remains poorly understood. The present work experimentally characterizes how foil mass ratio, pitching-axis location, and reduced frequency jointly govern the hydrodynamic and mechanical efficiencies of a semi-passive oscillating hydrofoil. Results show that rotational inertia redistributes actuator demand through phase-dependent torque exchange, while heave-pitch coupling can partially cancel this demand when favorably phased. Pitching-axis location modifies the phase and direction of the fluid torque through changes in the effective hydrodynamic moment arm. Reduced frequency governs the balance between enhanced unsteady loading and inertia-amplified actuator demand. Optimal performance is achieved within reduced frequency region of 0.125-0.16 using quarter-chord to one-third-chord pitching axes and relatively low foil mass ratios from about 0.5 to 2.0, yielding a peak mechanical efficiency of 33.96% -- which can diverge from the hydrodynamic efficiency by approximately 38.16% depending on configuration. Torque-loop analysis and PIV measurements show that this synchronization is a key mechanism governing the observed efficiency trends.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Renewable Energy, Volume 277, 126486 (2026)",
  "arxiv": "2606.11126",
  "author_total": 4,
  "authors": [
    {
      "name": "Zihan Zhang"
    },
    {
      "name": "Qimin Feng"
    },
    {
      "name": "Yuanhang Zhu"
    },
    {
      "name": "Qiang Zhong"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/99g61w1s8d22b.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.11126",
  "fulltext_url": null,
  "id": "99g61w1s8d22b",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.11126",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2606.11126",
  "pmcid": null,
  "pmid": null,
  "published": "2026-06-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/99g61w1s8d22b.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:03Z",
      "native_id": "2606.11126",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.11126"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.flu-dyn",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "Inertial effects on the mechanical efficiency of a semi-passive oscillating hydrofoil energy harvester",
  "title_text": "Inertial effects on the mechanical efficiency of a semi-passive oscillating hydrofoil energy harvester",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:03Z",
  "url": "https://research.draconitic.com/paper/99g61w1s8d22b",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1016/j.renene.2026.126486",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}