{
 "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": "list-ta-ring-3x2in",
 "name": "Build list: Thermoacoustic-Stirling ring generator, three 2 in units, pressurised",
 "kind": "list",
 "category": "Stirling engines",
 "group": "Guide",
 "year": null,
 "question": "What parts do I need to build a Thermoacoustic-Stirling ring generator, three 2 in units, pressurised?",
 "tags": [
  "list",
  "build",
  "thermoacoustic",
  "free piston",
  "linear alternator",
  "long earth society",
  "tri-clamp",
  "pressurised",
  "double acting",
  "ring",
  "helium",
  "torch"
 ],
 "aliases": [
  "double acting thermoacoustic generator",
  "thermoacoustic stirling generator tri clamp",
  "free piston thermoacoustic generator",
  "pressurised thermoacoustic engine helium",
  "thermoacoustic electricity propane"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": true,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/list-ta-ring-3x2in/",
 "sheet_txt": "https://xemstudio.com/objects/list-ta-ring-3x2in/sheet.txt",
 "sheet": {
  "basis": "Every part is a free STEP/STL on this site or a standard part with its own page; quantities are the full count, every screw, nut, gasket and clamp. Numbers from the linear network model in tools/gen_ta_power.py (Rott / Swift equations, written from the published method).",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A double-acting thermoacoustic-Stirling generator in 2 in tri-clamp: three cores and three free-piston alternators in a loop, charged with helium, one propane / butane torch under a drum.",
   "Numbers: 3 units · 20 bar helium · 25 Hz · onset 67 °C with the alternators open, 550 °C on the design load · ≈ 90 W electric for ≈ 341 W into the hot exchangers (27 %) at ±8 mm (model)"
  ],
  "table": {
   "columns": [
    "subsystem",
    "object",
    "parts",
    "qty",
    "note"
   ],
   "rows": [
    [
     null,
     "tri-clamp-custom-length-spools",
     "spool-2in-340.7mm",
     3,
     "core, one per unit: plain 2 in tube with full ferrules; exchangers, regenerator and buffer-tube liner inside"
    ],
    [
     null,
     "thermoacoustic-bore-spacer",
     "ta-spacer-2in-8.4",
     6,
     "gasket lip to each ambient exchanger, both ends of each core"
    ],
    [
     null,
     "thermoacoustic-slotted-exchanger-insert",
     "hx-insert-2in-14",
     6,
     "main ambient (top) and secondary ambient (bottom) exchanger of each core"
    ],
    [
     null,
     "regenerator-screen-disc-47-5",
     "screen-disc-47.5-m100",
     1500,
     "regenerator: 500 per core, 100 mm of 100-mesh × 0.10 screen"
    ],
    [
     null,
     "thermoacoustic-slotted-exchanger-insert",
     "hx-insert-2in-12",
     3,
     "hot exchanger, under each regenerator"
    ],
    [
     null,
     "thermoacoustic-buffer-tube-liner",
     "tbt-liner-2in-180",
     3,
     "thermal buffer tube: hot exchanger down to the secondary exchanger"
    ],
    [
     null,
     "tri-clamp-honed-cylinder-spool",
     "spool-2in-6in-honed-48.00",
     3,
     "piston cylinder under each core"
    ],
    [
     null,
     "free-piston-mover-2in",
     "mover-core-2in-130",
     3,
     "mover core: the piston's magnetic return path and crown"
    ],
    [
     null,
     "free-piston-mover-2in",
     "mover-sleeve-48x130",
     3,
     "mover sleeve: the running surface in the honed bore"
    ],
    [
     null,
     "neodymium-block-magnets",
     "magnet-block-30x10x4",
     144,
     "48 per mover: four rows of 12, rows alternately N and S outward"
    ],
    [
     null,
     "canned-linear-alternator-stator-2in",
     "stator-bobbin-half-2in-112",
     6,
     "two halves round each honed spool's tube"
    ],
    [
     null,
     "canned-linear-alternator-stator-2in",
     "stator-coil-2in-14x7",
     12,
     "four per alternator, wound in place, alternate hands, in series"
    ],
    [
     null,
     "canned-linear-alternator-stator-2in",
     "stator-iron-half-2in-112",
     6,
     "return-path shell halves, clamp the bobbin to the tube"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x16",
     18,
     "return-shell ears, three each side"
    ],
    [
     null,
     "tri-clamp-flexure-carrier",
     "flexure-carrier-2in-60",
     3,
     "under each cylinder: flexure stack A on its upper ledge, B on its lower"
    ],
    [
     null,
     "spiral-flexure-bearing",
     "flexure-40-3arm-w1.6-t0.5",
     12,
     "two per stack, opposite spiral hand"
    ],
    [
     null,
     "flexure-stack-spacer",
     "spacer-40-t2",
     6,
     "between the leaf rims"
    ],
    [
     null,
     "flexure-rim-clamp-plate",
     "clamp-plate-40",
     6,
     "on each stack's rims"
    ],
    [
     null,
     "flexure-hub-clamp-washer",
     "hub-clamp-40-b4",
     6,
     "between the leaf hubs"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m3x10",
     18,
     "stack rims into the carrier ledges (tapped M3)"
    ],
    [
     null,
     "threaded-rods-metric",
     "rod-m4x195.9",
     3,
     "mover crown (tapped M4) down through both stacks"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     39,
     "hub nuts (4 per rod), return-shell ears (6 per unit), drum tabs (3), hangers (2 per hanger)"
    ],
    [
     null,
     "flat-washers-metric",
     "washer-m4",
     12,
     "under each hub nut"
    ],
    [
     null,
     "tri-clamp-caps-with-welded-boss",
     "cap-2in-x-0.75in-ferrule",
     6,
     "top of each core and bottom of each carrier: the ¾ in lines join here"
    ],
    [
     null,
     "tri-clamp-gasket",
     "tc-gasket-2in",
     12,
     "Type B profile at every 2 in joint, rated above the relief setting at the joint's temperature"
    ],
    [
     null,
     "sanitary-clamp-elbows",
     "elbow-90-0.75in",
     12,
     "four per line"
    ],
    [
     null,
     "sanitary-clamp-spools",
     "spool-0.75in-3in",
     6,
     "bottom run and the riser's lowest spool"
    ],
    [
     null,
     "sanitary-clamp-spools",
     "spool-0.75in-6in",
     3,
     "top of each riser"
    ],
    [
     null,
     "tri-clamp-custom-length-spools",
     "spool-0.75in-146.7mm",
     3,
     "riser between the tee and the cross"
    ],
    [
     null,
     "sanitary-clamp-tees",
     "tee-0.75in",
     3,
     "fill branch"
    ],
    [
     null,
     "sanitary-clamp-crosses",
     "cross-0.75in",
     3,
     "gauge and relief branches"
    ],
    [
     null,
     "tri-clamp-caps-with-welded-boss",
     "cap-0.75in-x-1-4npt",
     9,
     "close the tee and cross branches; each carries a 1/4 NPT instrument"
    ],
    [
     null,
     "npt-thread-envelopes",
     "npt-1-4-male",
     9,
     "1/4 NPT stems of the fill valve, pressure gauge and relief valve on each line"
    ],
    [
     null,
     "sanitary-clamp-gaskets",
     "gasket-0.75in",
     42,
     "Type B profile at every ¾ in joint, rated above the relief setting"
    ],
    [
     null,
     "thermoacoustic-burner-drum",
     "drum-ring-lower",
     1,
     "round the three hot zones; its flue comes down to the torch"
    ],
    [
     null,
     "thermoacoustic-burner-drum",
     "drum-ring-upper",
     1,
     "vents in the top"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x20",
     9,
     "drum tabs (3), hangers (2 per hanger)"
    ],
    [
     null,
     "tri-clamp-torch-stand",
     "torch-stand-40",
     1,
     "on the bench under the flue; the heat source is a propane / butane torch head in its ring"
    ],
    [
     null,
     "set-screws-metric",
     "set-m4x10",
     3,
     "centre the torch head"
    ],
    [
     null,
     "thermoacoustic-water-jacket",
     "ta-jacket-half-2in-14",
     12,
     "optional: over the two ambient exchangers of each core, two halves each"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x25",
     12,
     "optional: jacket ears"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     12,
     "optional: jacket ears"
    ],
    [
     null,
     "thermoacoustic-fin-sleeve",
     "fin-sleeve-half-2in-34",
     6,
     "optional: over each hot exchanger inside the drum, two halves each"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x16",
     6,
     "optional: fin-sleeve ears"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     6,
     "optional: fin-sleeve ears"
    ],
    [
     null,
     "2020-aluminum-extrusion",
     "2020-200",
     12,
     "per stand: two rails on the bench, two uprights"
    ],
    [
     null,
     "t-slot-corner-brackets",
     "corner-bracket-20",
     12,
     "two per upright"
    ],
    [
     null,
     "button-head-screws-metric",
     "button-m5x10",
     24,
     "bracket screws, a washer each"
    ],
    [
     null,
     "flat-washers-metric",
     "washer-m5",
     24,
     ""
    ],
    [
     null,
     "drop-in-t-nuts",
     "tnut-dropin-20-m5",
     30,
     "8 per stand for the brackets, 2 for its hanger"
    ],
    [
     null,
     "spool-hanger-collars",
     "hanger-2in-tab",
     3,
     "round each flexure carrier's neck: the column hangs from it"
    ],
    [
     null,
     "spool-hanger-collars",
     "hanger-2in-plain",
     3,
     ""
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x16",
     6,
     "hanger bars into the uprights"
    ]
   ]
  }
 },
 "sheet_text": "Build list: Thermoacoustic-Stirling ring generator, three 2 in units, pressurised — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-ta-ring-3x2in/  (CC BY 4.0)\nBasis: Every part is a free STEP/STL on this site or a standard part with its own page; quantities are the full count, every screw, nut, gasket and clamp. Numbers from the linear network model in tools/gen_ta_power.py (Rott / Swift equations, written from the published method).\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A double-acting thermoacoustic-Stirling generator in 2 in tri-clamp: three cores and three free-piston alternators in a loop, charged with helium, one propane / butane torch under a drum.\n- Numbers: 3 units · 20 bar helium · 25 Hz · onset 67 °C with the alternators open, 550 °C on the design load · ≈ 90 W electric for ≈ 341 W into the hot exchangers (27 %) at ±8 mm (model)\n\nsubsystem  object  parts  qty  note\nNone  tri-clamp-custom-length-spools  spool-2in-340.7mm  3  core, one per unit: plain 2 in tube with full ferrules; exchangers, regenerator and buffer-tube liner inside\nNone  thermoacoustic-bore-spacer  ta-spacer-2in-8.4  6  gasket lip to each ambient exchanger, both ends of each core\nNone  thermoacoustic-slotted-exchanger-insert  hx-insert-2in-14  6  main ambient (top) and secondary ambient (bottom) exchanger of each core\nNone  regenerator-screen-disc-47-5  screen-disc-47.5-m100  1500  regenerator: 500 per core, 100 mm of 100-mesh × 0.10 screen\nNone  thermoacoustic-slotted-exchanger-insert  hx-insert-2in-12  3  hot exchanger, under each regenerator\nNone  thermoacoustic-buffer-tube-liner  tbt-liner-2in-180  3  thermal buffer tube: hot exchanger down to the secondary exchanger\nNone  tri-clamp-honed-cylinder-spool  spool-2in-6in-honed-48.00  3  piston cylinder under each core\nNone  free-piston-mover-2in  mover-core-2in-130  3  mover core: the piston's magnetic return path and crown\nNone  free-piston-mover-2in  mover-sleeve-48x130  3  mover sleeve: the running surface in the honed bore\nNone  neodymium-block-magnets  magnet-block-30x10x4  144  48 per mover: four rows of 12, rows alternately N and S outward\nNone  canned-linear-alternator-stator-2in  stator-bobbin-half-2in-112  6  two halves round each honed spool's tube\nNone  canned-linear-alternator-stator-2in  stator-coil-2in-14x7  12  four per alternator, wound in place, alternate hands, in series\nNone  canned-linear-alternator-stator-2in  stator-iron-half-2in-112  6  return-path shell halves, clamp the bobbin to the tube\nNone  socket-head-cap-screws-metric  shcs-m4x16  18  return-shell ears, three each side\nNone  tri-clamp-flexure-carrier  flexure-carrier-2in-60  3  under each cylinder: flexure stack A on its upper ledge, B on its lower\nNone  spiral-flexure-bearing  flexure-40-3arm-w1.6-t0.5  12  two per stack, opposite spiral hand\nNone  flexure-stack-spacer  spacer-40-t2  6  between the leaf rims\nNone  flexure-rim-clamp-plate  clamp-plate-40  6  on each stack's rims\nNone  flexure-hub-clamp-washer  hub-clamp-40-b4  6  between the leaf hubs\nNone  socket-head-cap-screws-metric  shcs-m3x10  18  stack rims into the carrier ledges (tapped M3)\nNone  threaded-rods-metric  rod-m4x195.9  3  mover crown (tapped M4) down through both stacks\nNone  hex-nuts-metric  nut-m4  39  hub nuts (4 per rod), return-shell ears (6 per unit), drum tabs (3), hangers (2 per hanger)\nNone  flat-washers-metric  washer-m4  12  under each hub nut\nNone  tri-clamp-caps-with-welded-boss  cap-2in-x-0.75in-ferrule  6  top of each core and bottom of each carrier: the ¾ in lines join here\nNone  tri-clamp-gasket  tc-gasket-2in  12  Type B profile at every 2 in joint, rated above the relief setting at the joint's temperature\nNone  sanitary-clamp-elbows  elbow-90-0.75in  12  four per line\nNone  sanitary-clamp-spools  spool-0.75in-3in  6  bottom run and the riser's lowest spool\nNone  sanitary-clamp-spools  spool-0.75in-6in  3  top of each riser\nNone  tri-clamp-custom-length-spools  spool-0.75in-146.7mm  3  riser between the tee and the cross\nNone  sanitary-clamp-tees  tee-0.75in  3  fill branch\nNone  sanitary-clamp-crosses  cross-0.75in  3  gauge and relief branches\nNone  tri-clamp-caps-with-welded-boss  cap-0.75in-x-1-4npt  9  close the tee and cross branches; each carries a 1/4 NPT instrument\nNone  npt-thread-envelopes  npt-1-4-male  9  1/4 NPT stems of the fill valve, pressure gauge and relief valve on each line\nNone  sanitary-clamp-gaskets  gasket-0.75in  42  Type B profile at every ¾ in joint, rated above the relief setting\nNone  thermoacoustic-burner-drum  drum-ring-lower  1  round the three hot zones; its flue comes down to the torch\nNone  thermoacoustic-burner-drum  drum-ring-upper  1  vents in the top\nNone  socket-head-cap-screws-metric  shcs-m4x20  9  drum tabs (3), hangers (2 per hanger)\nNone  tri-clamp-torch-stand  torch-stand-40  1  on the bench under the flue; the heat source is a propane / butane torch head in its ring\nNone  set-screws-metric  set-m4x10  3  centre the torch head\nNone  thermoacoustic-water-jacket  ta-jacket-half-2in-14  12  optional: over the two ambient exchangers of each core, two halves each\nNone  socket-head-cap-screws-metric  shcs-m4x25  12  optional: jacket ears\nNone  hex-nuts-metric  nut-m4  12  optional: jacket ears\nNone  thermoacoustic-fin-sleeve  fin-sleeve-half-2in-34  6  optional: over each hot exchanger inside the drum, two halves each\nNone  socket-head-cap-screws-metric  shcs-m4x16  6  optional: fin-sleeve ears\nNone  hex-nuts-metric  nut-m4  6  optional: fin-sleeve ears\nNone  2020-aluminum-extrusion  2020-200  12  per stand: two rails on the bench, two uprights\nNone  t-slot-corner-brackets  corner-bracket-20  12  two per upright\nNone  button-head-screws-metric  button-m5x10  24  bracket screws, a washer each\nNone  flat-washers-metric  washer-m5  24  \nNone  drop-in-t-nuts  tnut-dropin-20-m5  30  8 per stand for the brackets, 2 for its hanger\nNone  spool-hanger-collars  hanger-2in-tab  3  round each flexure carrier's neck: the column hangs from it\nNone  spool-hanger-collars  hanger-2in-plain  3  \nNone  socket-head-cap-screws-metric  shcs-m5x16  6  hanger bars into the uprights\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Applied Energy (Z. Wu, G. Yu, L. Zhang, W. Dai, E. Luo): Development of a 3 kW double-acting thermoacoustic Stirling electric generator, 136, 866-872 (2014): three engines and three linear alternators in a loop, 5 MPa helium, 86 Hz, 1.57 kW electric, 16.8 % — web — journal article; cited [verify license at link] — https://doi.org/10.1016/j.apenergy.2014.04.105\n- Applied Energy (T. Bi, Z. Wu, L. Zhang, G. Yu, E. Luo, W. Dai): Development of a 5 kW traveling-wave thermoacoustic electric generator, 185, 1355-1361 (2017): three-stage looped engine, 6 MPa helium, 650 °C, 4.69 kW at 15.6 %, 18.4 % peak — web — journal article; cited [verify license at link] — https://doi.org/10.1016/j.apenergy.2015.12.034\n- J. Acoust. Soc. Am. (S. Backhaus, G. W. Swift): A thermoacoustic-Stirling heat engine: detailed study, JASA 107(6), 3148 (2000): torus with inertance and compliance, thermal buffer tube, jet pump against Gedeon streaming — web — journal article; cited [verify license at link] — https://doi.org/10.1121/1.429343\n- Appl. Phys. Lett. (S. Backhaus, E. Tward, M. Petach): Traveling-wave thermoacoustic electric generator, APL 85, 1085 (2004): a thermoacoustic-Stirling engine driving linear alternators, 18 % heat to electricity — web — journal article; cited [verify license at link] — https://doi.org/10.1063/1.1781739\n- Applied Energy (D. M. Sun, K. Wang, X. J. Zhang, Y. N. Guo, Y. Xu, L. M. Qiu): A traveling-wave thermoacoustic electric generator with a variable electric R-C load, 106, 377-382 (2013): 3 MPa helium, about 65 Hz, 345 W at 9.3 %, 12.3 % peak; series capacitor on the alternator — web — journal article; cited [verify license at link] — https://doi.org/10.1016/j.apenergy.2013.01.051\n- Applied Energy (Z. Yu, A. J. Jaworski, S. Backhaus): Travelling-wave thermoacoustic electricity generator using an ultra-compliant alternator, 99, 135-145 (2012): atmospheric air, a loudspeaker as the alternator, 11.6 W — web — journal article; cited [verify license at link] — https://doi.org/10.1016/j.apenergy.2012.04.046\n- G. W. Swift (Acoustical Society of America / LANL): Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Rott's equations, the energy equation, screen relations; the method behind DeltaEC) — web, book — cited [verify license at link] — https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/\n- J. Thermophysics and Heat Transfer (G. W. Swift, W. C. Ward): Simple harmonic analysis of regenerators, 10(4), 652-662 (1996): stacked-screen friction c1(φ) = 1268 − 3545φ + 2544φ² — web — journal article; cited [verify license at link] — https://doi.org/10.2514/3.842\n- Steel & O'Brien: Clamp ratings (clamp + elastomer gasket assembly): 2 in single-pin 450 psi at 70 °F / 300 psi at 250 °F; high-pressure bolted 1000 / 800 psi — PDF — manufacturer's rating sheet; numbers cited — https://www.steelobrien.com/wp-content/uploads/2020/06/SOB-Clamp-Ratings.pdf\n- NIST Chemistry WebBook: Thermophysical properties of fluid systems (helium, air): viscosity and conductivity used for the model's fits — web — US Government data — https://webbook.nist.gov/chemistry/fluid/\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nXem Studio scan: not planned; the official CAD above covers it.\nAPI: https://xemstudio.com/api/geometry?object=list-ta-ring-3x2in\n",
 "sources": [
  {
   "publisher": "Applied Energy (Z. Wu, G. Yu, L. Zhang, W. Dai, E. Luo)",
   "title": "Development of a 3 kW double-acting thermoacoustic Stirling electric generator, 136, 866-872 (2014): three engines and three linear alternators in a loop, 5 MPa helium, 86 Hz, 1.57 kW electric, 16.8 %",
   "url": "https://doi.org/10.1016/j.apenergy.2014.04.105",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Applied Energy (T. Bi, Z. Wu, L. Zhang, G. Yu, E. Luo, W. Dai)",
   "title": "Development of a 5 kW traveling-wave thermoacoustic electric generator, 185, 1355-1361 (2017): three-stage looped engine, 6 MPa helium, 650 °C, 4.69 kW at 15.6 %, 18.4 % peak",
   "url": "https://doi.org/10.1016/j.apenergy.2015.12.034",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "J. Acoust. Soc. Am. (S. Backhaus, G. W. Swift)",
   "title": "A thermoacoustic-Stirling heat engine: detailed study, JASA 107(6), 3148 (2000): torus with inertance and compliance, thermal buffer tube, jet pump against Gedeon streaming",
   "url": "https://doi.org/10.1121/1.429343",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Appl. Phys. Lett. (S. Backhaus, E. Tward, M. Petach)",
   "title": "Traveling-wave thermoacoustic electric generator, APL 85, 1085 (2004): a thermoacoustic-Stirling engine driving linear alternators, 18 % heat to electricity",
   "url": "https://doi.org/10.1063/1.1781739",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Applied Energy (D. M. Sun, K. Wang, X. J. Zhang, Y. N. Guo, Y. Xu, L. M. Qiu)",
   "title": "A traveling-wave thermoacoustic electric generator with a variable electric R-C load, 106, 377-382 (2013): 3 MPa helium, about 65 Hz, 345 W at 9.3 %, 12.3 % peak; series capacitor on the alternator",
   "url": "https://doi.org/10.1016/j.apenergy.2013.01.051",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Applied Energy (Z. Yu, A. J. Jaworski, S. Backhaus)",
   "title": "Travelling-wave thermoacoustic electricity generator using an ultra-compliant alternator, 99, 135-145 (2012): atmospheric air, a loudspeaker as the alternator, 11.6 W",
   "url": "https://doi.org/10.1016/j.apenergy.2012.04.046",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "G. W. Swift (Acoustical Society of America / LANL)",
   "title": "Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Rott's equations, the energy equation, screen relations; the method behind DeltaEC)",
   "url": "https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/",
   "formats": [
    "web",
    "book"
   ],
   "license": "cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "J. Thermophysics and Heat Transfer (G. W. Swift, W. C. Ward)",
   "title": "Simple harmonic analysis of regenerators, 10(4), 652-662 (1996): stacked-screen friction c1(φ) = 1268 − 3545φ + 2544φ²",
   "url": "https://doi.org/10.2514/3.842",
   "formats": [
    "web"
   ],
   "license": "journal article; cited",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Steel & O'Brien",
   "title": "Clamp ratings (clamp + elastomer gasket assembly): 2 in single-pin 450 psi at 70 °F / 300 psi at 250 °F; high-pressure bolted 1000 / 800 psi",
   "url": "https://www.steelobrien.com/wp-content/uploads/2020/06/SOB-Clamp-Ratings.pdf",
   "formats": [
    "PDF"
   ],
   "license": "manufacturer's rating sheet; numbers cited",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "NIST Chemistry WebBook",
   "title": "Thermophysical properties of fluid systems (helium, air): viscosity and conductivity used for the model's fits",
   "url": "https://webbook.nist.gov/chemistry/fluid/",
   "formats": [
    "web"
   ],
   "license": "US Government data",
   "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": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "free-piston-mover-2in",
  "canned-linear-alternator-stator-2in",
  "tri-clamp-honed-cylinder-spool",
  "tri-clamp-flexure-carrier",
  "thermoacoustic-slotted-exchanger-insert",
  "regenerator-screen-disc-47-5",
  "thermoacoustic-burner-drum",
  "tri-clamp-custom-length-spools",
  "tri-clamp-caps-with-welded-boss",
  "list-ta-twin-piston-2in",
  "list-free-piston-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": [],
 "faq": [
  {
   "q": "How much electricity does it make?",
   "a": "About 90 W in the model at 20 bar helium and 550 °C, limited by the alternators' ±8 mm stroke; I expect half to two-thirds of that on the built engine."
  },
  {
   "q": "Can it run unpressurised?",
   "a": "It starts at 1 bar only near 511 °C (helium) or 204 °C (air) and makes milliwatts to a fraction of a watt: its pistons and alternators are sized for 20 bar."
  },
  {
   "q": "Why helium?",
   "a": "Same pressure, more power: helium's sound speed and conductivity let the regenerator pass more acoustic power with less loss. Air at 20 bar gives about nine-tenths of helium's output in the model."
  },
  {
   "q": "Why three units?",
   "a": "Each piston must be 120° from the next for the regenerators to see a traveling wave; with three units the pistons themselves do the phasing, and they block the steady flow a loop would otherwise carry."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/list-ta-ring-3x2in/index.md"
}