{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "fpse-regenerator-screen-ring",
 "name": "Annular regenerator screen ring: 100 mesh, Ø47.5 / Ø41.5, for a 2 in tri-clamp Stirling",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Stirling & thermoacoustic",
 "year": null,
 "question": "How do I make an annular regenerator for a 2 in tri-clamp free-piston Stirling?",
 "tags": [
  "regenerator",
  "screen",
  "mesh",
  "stirling",
  "tri-clamp",
  "long earth society"
 ],
 "aliases": [
  "annular regenerator screens",
  "stirling regenerator mesh ring",
  "100 mesh regenerator"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/fpse-regenerator-screen-ring/",
 "sheet_txt": "https://xemstudio.com/objects/fpse-regenerator-screen-ring/sheet.txt",
 "sheet": {
  "basis": "Urieli & Berchowitz screen relations: porosity 1 − π m d / 4, hydraulic diameter d·β/(1 − β); heat transfer and friction from Gedeon & Wood (1996)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "389 rings of 100 mesh, 0.1 mm wire screen stacked 77.8 mm high in the annulus between the liner (Ø41.5) and the hot spool's bore (Ø47.5), on the liner's spokes and under its rim.",
   "Porosity 0.691, hydraulic diameter 0.223 mm, frontal area 419 mm². At the design point the regenerator's NTU is 165 (effectiveness 0.9940), its enthalpy loss 5.4 W.",
   "Stack the rings with the weave of each layer turned a little against the last; fill the annulus exactly, so the rim holds the stack."
  ],
  "table": {
   "columns": [
    "feature",
    "value"
   ],
   "rows": [
    [
     "ring",
     "Ø47.5 / Ø41.5 × 0.2"
    ],
    [
     "count",
     389
    ],
    [
     "screen",
     "100 mesh, 0.1 mm wire"
    ],
    [
     "porosity",
     0.691
    ],
    [
     "hydraulic Ø mm",
     0.223
    ]
   ]
  }
 },
 "sheet_text": "Annular regenerator screen ring: 100 mesh, Ø47.5 / Ø41.5, for a 2 in tri-clamp Stirling — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/fpse-regenerator-screen-ring/  (CC BY 4.0)\nBasis: Urieli & Berchowitz screen relations: porosity 1 − π m d / 4, hydraulic diameter d·β/(1 − β); heat transfer and friction from Gedeon & Wood (1996)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 389 rings of 100 mesh, 0.1 mm wire screen stacked 77.8 mm high in the annulus between the liner (Ø41.5) and the hot spool's bore (Ø47.5), on the liner's spokes and under its rim.\n- Porosity 0.691, hydraulic diameter 0.223 mm, frontal area 419 mm². At the design point the regenerator's NTU is 165 (effectiveness 0.9940), its enthalpy loss 5.4 W.\n- Stack the rings with the weave of each layer turned a little against the last; fill the annulus exactly, so the rim holds the stack.\n\nfeature  value\nring  Ø47.5 / Ø41.5 × 0.2\ncount  389\nscreen  100 mesh, 0.1 mm wire\nporosity  0.691\nhydraulic Ø mm  0.223\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Ohio University (Urieli): Stirling cycle machine analysis: ideal adiabatic and simple analysis (after Urieli & Berchowitz, Stirling Cycle Engine Analysis, 1984) — web — author's site — https://www.ohio.edu/mechanical/stirling/\n- NASA (NTRS, public domain): Gedeon & Wood (1996), Oscillating-flow regenerator test rig: correlations for screens and felts, NASA CR-198442 (f = 129/Re + 2.91 Re^-0.103; Nu = (1 + 0.99 Pe^0.66) β^1.79) — PDF — US Government work, public domain — https://ntrs.nasa.gov/citations/19960015878\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/fpse-regenerator-screen-ring/index.json\nAPI: https://xemstudio.com/api/geometry?object=fpse-regenerator-screen-ring\n",
 "sources": [
  {
   "publisher": "Ohio University (Urieli)",
   "title": "Stirling cycle machine analysis: ideal adiabatic and simple analysis (after Urieli & Berchowitz, Stirling Cycle Engine Analysis, 1984)",
   "url": "https://www.ohio.edu/mechanical/stirling/",
   "formats": [
    "web"
   ],
   "license": "author's site",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "NASA (NTRS, public domain)",
   "title": "Gedeon & Wood (1996), Oscillating-flow regenerator test rig: correlations for screens and felts, NASA CR-198442 (f = 129/Re + 2.91 Re^-0.103; Nu = (1 + 0.99 Pe^0.66) β^1.79)",
   "url": "https://ntrs.nasa.gov/citations/19960015878",
   "formats": [
    "PDF"
   ],
   "license": "US Government work, public domain",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "fpse-displacer-cylinder",
  "regenerator-mesh-disc",
  "list-fpse-generator-2in"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [
  {
   "feature": "OD",
   "exact": "Ø47.5",
   "mates": "hot spool bore",
   "fit": "slide",
   "files": "all"
  },
  {
   "feature": "ID",
   "exact": "Ø41.5",
   "mates": "liner tube OD",
   "fit": "slide",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "Why 100 mesh?",
   "a": "At 40–50 Hz in helium the gas needs a fine matrix to give up and take back its heat each stroke; 100 mesh keeps the effectiveness above 0.99 while the friction stays a fraction of the cycle's work."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "regen-ring-41.5x47.5x0.2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/fpse-regenerator-screen-ring/regen-ring-41.5x47.5x0.2.step",
   "stl": "https://xemstudio.com/files/hardware/fpse-regenerator-screen-ring/regen-ring-41.5x47.5x0.2.stl",
   "note": "regenerator ring: one layer of 100 mesh woven screen (0.1 mm wire) cut to Ø47.5 / Ø41.5, drawn 0.2 thick (two wire diameters)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/fpse-regenerator-screen-ring/index.md"
}