{ "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-loop-2in", "name": "Build list: Thermoacoustic traveling-wave loop, 2 in tri-clamp", "kind": "list", "category": "Stirling engines", "group": "Guide", "year": null, "question": "What parts do I need to build a Thermoacoustic traveling-wave loop, 2 in tri-clamp?", "tags": [ "list", "build", "thermoacoustic", "long earth society", "tri-clamp", "traveling wave", "loop", "torch", "speaker", "alternator", "membrane" ], "aliases": [ "traveling wave thermoacoustic engine tri clamp", "looped tube thermoacoustic engine", "thermoacoustic stirling engine build", "tashe tri clamp", "propane thermoacoustic engine", "thermoacoustic linear alternator", "thermoacoustic stirling hybrid membrane" ], "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-loop-2in/", "sheet_txt": "https://xemstudio.com/objects/list-ta-loop-2in/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, pin, gasket and clamp; acoustic numbers from the low-amplitude network model in tools/gen_ta_family.py (Rott's equations, Swift).", "overall_mm": { "length": null, "width": null, "height": null }, "notes": [ "A looped traveling-wave thermoacoustic engine in 2 in tri-clamp, torch-heated, with a choice of output on the resonator (a 40 mm loudspeaker or the free-piston linear alternator) and an optional membrane in the loop.", "Numbers: Legs 359 mm apart, core 6 in, regenerator Ø44 × 40 of 50-mesh × 0.22 mm screen (r_h 107 µm, porosity 0.66) · 286 Hz · onset ≈ 184 °C at the hot exchanger · ≈ 24 W of sound into a matched end load at 3 kPa (3 % of 1 bar) at the tee · output: loudspeaker cap (A) or linear alternator (B)" ], "table": { "columns": [ "subsystem", "object", "parts", "qty", "note" ], "rows": [ [ null, "sanitary-clamp-elbows", "elbow-90-2in", 4, "the four corners of the loop" ], [ null, "sanitary-clamp-tees", "tee-2in", 2, "top: resonator branch up; bottom: capped branch toward the front (the feedback compliance)" ], [ null, "tri-clamp-spool", "tc-spool-2in-6in", 2, "left leg = the core (exchangers, regenerator, thermal buffer tube); right leg = feedback" ], [ null, "tri-clamp-spool", "tc-spool-2in-12in", 1, "resonator, up from the top tee" ], [ null, "tri-clamp-end-cap", "tc-cap-2in-flat", 1, "closes the bottom tee's branch" ], [ null, "tri-clamp-gasket", "tc-gasket-2in", 9, "Type B at the loop, branch-cap and resonator joints (the right leg's lower joint is chosen below)" ], [ null, "tri-clamp-clamps", "clamp-half-2in", 20, "10 joints, two halves each" ], [ null, "socket-head-cap-screws-metric", "shcs-m5x30", 20, "two per clamp" ], [ null, "hex-nuts-metric", "nut-m5", 20, "in the clamps' hex traps" ], [ null, "thermoacoustic-bore-spacer", "ta-spacer-2in-8.4", 2, "core ends: gasket lip to each ambient exchanger" ], [ null, "thermoacoustic-heat-exchanger", "heat-exchanger-cold-2in", 2, "main ambient exchanger (top of the regenerator) and secondary ambient exchanger (bottom of the buffer tube)" ], [ null, "regenerator-cage", "regenerator-cage-47-5x40", 1, "under the main ambient exchanger" ], [ null, "regenerator-mesh-disc", "mesh-disc-44mm", 80, "fill the cage, 40 mm: 50-mesh screen, 0.22 mm wire" ], [ null, "dowel-pins-metric", "dowel-3x30", 1, "with the 3 × 10, fills the discs' Ø3 centre holes end to end (no bypass)" ], [ null, "dowel-pins-metric", "dowel-3x10", 1, "" ], [ null, "thermoacoustic-heat-exchanger", "heat-exchanger-hot-2in", 1, "under the regenerator, inside the flame shroud" ], [ null, "thermoacoustic-bore-spacer", "ta-spacer-2in-61.7", 1, "thermal buffer tube liner: hot exchanger down to the secondary exchanger" ], [ null, "thermoacoustic-water-jacket", "ta-jacket-half-2in-14", 4, "optional heat exchanger: two water jackets on the core, over the two ambient exchangers (9.35 from each face); without them the engine needs more heat to start, or cool those two bands any way you like" ], [ null, "socket-head-cap-screws-metric", "shcs-m4x25", 4, "optional: jacket ears (only with the jackets)" ], [ null, "hex-nuts-metric", "nut-m4", 4, "optional: jacket ears (only with the jackets)" ], [ null, "thermoacoustic-hot-shroud", "ta-shroud-2in-front", 1, "flame shroud round the hot exchanger, with the flue down to the torch" ], [ null, "thermoacoustic-hot-shroud", "ta-shroud-2in-back", 1, "" ], [ null, "socket-head-cap-screws-metric", "shcs-m4x25", 2, "shroud ears" ], [ null, "hex-nuts-metric", "nut-m4", 6, "shroud (2), hangers (4)" ], [ null, "tri-clamp-torch-stand", "torch-stand-40", 1, "on the bench under the flue, 25 below it; the heat source is a propane / butane torch head in the ring" ], [ null, "set-screws-metric", "set-m4x10", 3, "centre the torch head in the ring" ], [ null, "tri-clamp-gasket", "tc-gasket-2in", 1, "choose one right-leg joint, G (gasket): under the right leg" ], [ null, "tri-clamp-diaphragm-membrane", "membrane-2in", 1, "choose one right-leg joint, M (membrane): in place of the gasket under the right leg: blocks the steady flow round the loop" ], [ null, "tri-clamp-diaphragm-disc", "diaphragm-disc-2in", 1, "choose one right-leg joint, M (membrane): centre disc, boss up into the right leg" ], [ null, "tri-clamp-diaphragm-disc", "diaphragm-backing-2in", 1, "choose one right-leg joint, M (membrane): under the membrane" ], [ null, "socket-head-cap-screws-metric", "shcs-m2x8", 3, "choose one right-leg joint, M (membrane): heads under the backing disc" ], [ null, "hex-nuts-metric", "nut-m2", 3, "choose one right-leg joint, M (membrane): on the centre disc" ], [ null, "tri-clamp-gasket", "tc-gasket-2in", 1, "choose one output, A (loudspeaker): resonator top" ], [ null, "tri-clamp-clamps", "clamp-half-2in", 2, "choose one output, A (loudspeaker): 1 joint, two halves each" ], [ null, "socket-head-cap-screws-metric", "shcs-m5x30", 2, "choose one output, A (loudspeaker): two per clamp" ], [ null, "hex-nuts-metric", "nut-m5", 2, "choose one output, A (loudspeaker): in the clamps' hex traps" ], [ null, "thermoacoustic-driver-cap", "driver-cap-2in-40mm-speaker", 1, "choose one output, A (loudspeaker): closes the resonator; Ø28 port to the speaker cone" ], [ null, "loudspeaker-envelope-40mm", "speaker-envelope-40mm", 1, "choose one output, A (loudspeaker): 40 mm loudspeaker in the cap's socket, cone toward the gas" ], [ null, "tri-clamp-gasket", "tc-gasket-2in", 1, "choose one output, B (linear alternator): resonator top to the 3 in spool" ], [ null, "tri-clamp-clamps", "clamp-half-2in", 4, "choose one output, B (linear alternator): 2 joints, two halves each" ], [ null, "socket-head-cap-screws-metric", "shcs-m5x30", 4, "choose one output, B (linear alternator): two per clamp" ], [ null, "hex-nuts-metric", "nut-m5", 4, "choose one output, B (linear alternator): in the clamps' hex traps" ], [ null, "tri-clamp-spool", "tc-spool-2in-3in", 1, "choose one output, B (linear alternator): piston cylinder at the resonator end" ], [ null, "tri-clamp-hot-gasket", "hot-gasket-2in", 1, "choose one output, B (linear alternator): flat, bore ID, under the flexure head: the piston skirt passes it" ], [ null, "tri-clamp-flexure-head", "fp-flexure-head-2in", 1, "choose one output, B (linear alternator): clamps on the 3 in spool, carries flexure stack A" ], [ null, "tri-clamp-power-piston", "piston-2in", 1, "choose one output, B (linear alternator): full-bore, closed crown (no rod hole: the resonator stays sealed)" ], [ null, "tri-clamp-piston-plug", "fp-piston-plug-2in", 1, "choose one output, B (linear alternator): in the skirt, carries the tube rod" ], [ null, "dowel-pins-metric", "dowel-3x16", 2, "choose one output, B (linear alternator): wrist dowels through bosses and plug legs" ], [ null, "tube-piston-rods-5mm", "tube-rod-5x3.4x120", 1, "choose one output, B (linear alternator): plug to stack B, through stack A and the mover" ], [ null, "linear-alternator-mover", "alt-mover-35-2x8-10x3", 1, "choose one output, B (linear alternator): on the tube rod, centred in the coils" ], [ null, "set-screws-metric", "set-m3x3", 1, "choose one output, B (linear alternator): mover hub grub" ], [ null, "neodymium-disc-magnets", "magnet-10x3", 16, "choose one output, B (linear alternator): row 1 all N out, row 2 all S out" ], [ null, "linear-alternator-bobbin", "alt-bobbin-37-2x10", 1, "choose one output, B (linear alternator):" ], [ null, "linear-alternator-coil", "alt-coil-bay", 2, "choose one output, B (linear alternator): one per bay, the second wound the other way" ], [ null, "linear-alternator-back-iron-sleeve", "alt-back-iron-sleeve", 1, "choose one output, B (linear alternator):" ], [ null, "linear-alternator-housing", "alt-housing-2in-flex80", 1, "choose one output, B (linear alternator):" ], [ null, "linear-alternator-cap-ring", "alt-cap-2in-flex80", 1, "choose one output, B (linear alternator):" ], [ null, "tri-clamp-flexure-ring", "fp-flexure-ring-80", 1, "choose one output, B (linear alternator): carries stack B" ], [ null, "spiral-flexure-bearing", "flexure-80-3arm-w2.5-t2", 4, "choose one output, B (linear alternator): two per stack, opposite spiral hand" ], [ null, "flexure-stack-spacer", "spacer-80-t2", 2, "choose one output, B (linear alternator): between the leaf rims" ], [ null, "flexure-rim-clamp-plate", "clamp-plate-80", 2, "choose one output, B (linear alternator): on each stack's rims" ], [ null, "flexure-hub-clamp-washer", "hub-clamp-80-b5", 2, "choose one output, B (linear alternator): 2 mm hub washer between the leaf hubs" ], [ null, "flexure-hub-collar", "hub-collar-80-b5", 4, "choose one output, B (linear alternator): two per stack on the tube rod" ], [ null, "threaded-standoffs-metric", "standoff-m3x15", 3, "choose one output, B (linear alternator): head to alternator housing" ], [ null, "threaded-standoffs-metric", "standoff-m3x10", 3, "choose one output, B (linear alternator): alternator cap to the flexure ring" ], [ null, "socket-head-cap-screws-metric", "shcs-m3x20", 3, "choose one output, B (linear alternator): up through head and stack A into the 15 mm standoffs" ], [ null, "socket-head-cap-screws-metric", "shcs-m3x10", 7, "choose one output, B (linear alternator): 3 housing base flange, 4 hub-collar pinch screws" ], [ null, "socket-head-cap-screws-metric", "shcs-m3x12", 3, "choose one output, B (linear alternator): up through the housing's top flange and cap into the 10 mm standoffs" ], [ null, "socket-head-cap-screws-metric", "shcs-m3x16", 3, "choose one output, B (linear alternator): down through stack B and the ring into the 10 mm standoffs" ], [ null, "2020-aluminum-extrusion", "2020-200", 8, "per stand: two rails on the bench, two uprights" ], [ null, "t-slot-corner-brackets", "corner-bracket-20", 8, "two per upright, front and back, onto its rail" ], [ null, "button-head-screws-metric", "button-m5x10", 16, "bracket screws, a washer each" ], [ null, "flat-washers-metric", "washer-m5", 16, "" ], [ null, "drop-in-t-nuts", "tnut-dropin-20-m5", 20, "8 per stand for the brackets, 2 per hanger" ], [ null, "spool-hanger-collars", "hanger-2in-tab", 2, "clamps a spool tube; its bar bolts to both uprights" ], [ null, "spool-hanger-collars", "hanger-2in-plain", 2, "the other half of each hanger" ], [ null, "socket-head-cap-screws-metric", "shcs-m5x16", 4, "hanger bar into the uprights' T-nuts" ], [ null, "socket-head-cap-screws-metric", "shcs-m4x20", 4, "close each hanger on its tube" ] ] } }, "sheet_text": "Build list: Thermoacoustic traveling-wave loop, 2 in tri-clamp — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-ta-loop-2in/ (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, pin, gasket and clamp; acoustic numbers from the low-amplitude network model in tools/gen_ta_family.py (Rott's equations, Swift).\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A looped traveling-wave thermoacoustic engine in 2 in tri-clamp, torch-heated, with a choice of output on the resonator (a 40 mm loudspeaker or the free-piston linear alternator) and an optional membrane in the loop.\n- Numbers: Legs 359 mm apart, core 6 in, regenerator Ø44 × 40 of 50-mesh × 0.22 mm screen (r_h 107 µm, porosity 0.66) · 286 Hz · onset ≈ 184 °C at the hot exchanger · ≈ 24 W of sound into a matched end load at 3 kPa (3 % of 1 bar) at the tee · output: loudspeaker cap (A) or linear alternator (B)\n\nsubsystem object parts qty note\nNone sanitary-clamp-elbows elbow-90-2in 4 the four corners of the loop\nNone sanitary-clamp-tees tee-2in 2 top: resonator branch up; bottom: capped branch toward the front (the feedback compliance)\nNone tri-clamp-spool tc-spool-2in-6in 2 left leg = the core (exchangers, regenerator, thermal buffer tube); right leg = feedback\nNone tri-clamp-spool tc-spool-2in-12in 1 resonator, up from the top tee\nNone tri-clamp-end-cap tc-cap-2in-flat 1 closes the bottom tee's branch\nNone tri-clamp-gasket tc-gasket-2in 9 Type B at the loop, branch-cap and resonator joints (the right leg's lower joint is chosen below)\nNone tri-clamp-clamps clamp-half-2in 20 10 joints, two halves each\nNone socket-head-cap-screws-metric shcs-m5x30 20 two per clamp\nNone hex-nuts-metric nut-m5 20 in the clamps' hex traps\nNone thermoacoustic-bore-spacer ta-spacer-2in-8.4 2 core ends: gasket lip to each ambient exchanger\nNone thermoacoustic-heat-exchanger heat-exchanger-cold-2in 2 main ambient exchanger (top of the regenerator) and secondary ambient exchanger (bottom of the buffer tube)\nNone regenerator-cage regenerator-cage-47-5x40 1 under the main ambient exchanger\nNone regenerator-mesh-disc mesh-disc-44mm 80 fill the cage, 40 mm: 50-mesh screen, 0.22 mm wire\nNone dowel-pins-metric dowel-3x30 1 with the 3 × 10, fills the discs' Ø3 centre holes end to end (no bypass)\nNone dowel-pins-metric dowel-3x10 1 \nNone thermoacoustic-heat-exchanger heat-exchanger-hot-2in 1 under the regenerator, inside the flame shroud\nNone thermoacoustic-bore-spacer ta-spacer-2in-61.7 1 thermal buffer tube liner: hot exchanger down to the secondary exchanger\nNone thermoacoustic-water-jacket ta-jacket-half-2in-14 4 optional heat exchanger: two water jackets on the core, over the two ambient exchangers (9.35 from each face); without them the engine needs more heat to start, or cool those two bands any way you like\nNone socket-head-cap-screws-metric shcs-m4x25 4 optional: jacket ears (only with the jackets)\nNone hex-nuts-metric nut-m4 4 optional: jacket ears (only with the jackets)\nNone thermoacoustic-hot-shroud ta-shroud-2in-front 1 flame shroud round the hot exchanger, with the flue down to the torch\nNone thermoacoustic-hot-shroud ta-shroud-2in-back 1 \nNone socket-head-cap-screws-metric shcs-m4x25 2 shroud ears\nNone hex-nuts-metric nut-m4 6 shroud (2), hangers (4)\nNone tri-clamp-torch-stand torch-stand-40 1 on the bench under the flue, 25 below it; the heat source is a propane / butane torch head in the ring\nNone set-screws-metric set-m4x10 3 centre the torch head in the ring\nNone tri-clamp-gasket tc-gasket-2in 1 choose one right-leg joint, G (gasket): under the right leg\nNone tri-clamp-diaphragm-membrane membrane-2in 1 choose one right-leg joint, M (membrane): in place of the gasket under the right leg: blocks the steady flow round the loop\nNone tri-clamp-diaphragm-disc diaphragm-disc-2in 1 choose one right-leg joint, M (membrane): centre disc, boss up into the right leg\nNone tri-clamp-diaphragm-disc diaphragm-backing-2in 1 choose one right-leg joint, M (membrane): under the membrane\nNone socket-head-cap-screws-metric shcs-m2x8 3 choose one right-leg joint, M (membrane): heads under the backing disc\nNone hex-nuts-metric nut-m2 3 choose one right-leg joint, M (membrane): on the centre disc\nNone tri-clamp-gasket tc-gasket-2in 1 choose one output, A (loudspeaker): resonator top\nNone tri-clamp-clamps clamp-half-2in 2 choose one output, A (loudspeaker): 1 joint, two halves each\nNone socket-head-cap-screws-metric shcs-m5x30 2 choose one output, A (loudspeaker): two per clamp\nNone hex-nuts-metric nut-m5 2 choose one output, A (loudspeaker): in the clamps' hex traps\nNone thermoacoustic-driver-cap driver-cap-2in-40mm-speaker 1 choose one output, A (loudspeaker): closes the resonator; Ø28 port to the speaker cone\nNone loudspeaker-envelope-40mm speaker-envelope-40mm 1 choose one output, A (loudspeaker): 40 mm loudspeaker in the cap's socket, cone toward the gas\nNone tri-clamp-gasket tc-gasket-2in 1 choose one output, B (linear alternator): resonator top to the 3 in spool\nNone tri-clamp-clamps clamp-half-2in 4 choose one output, B (linear alternator): 2 joints, two halves each\nNone socket-head-cap-screws-metric shcs-m5x30 4 choose one output, B (linear alternator): two per clamp\nNone hex-nuts-metric nut-m5 4 choose one output, B (linear alternator): in the clamps' hex traps\nNone tri-clamp-spool tc-spool-2in-3in 1 choose one output, B (linear alternator): piston cylinder at the resonator end\nNone tri-clamp-hot-gasket hot-gasket-2in 1 choose one output, B (linear alternator): flat, bore ID, under the flexure head: the piston skirt passes it\nNone tri-clamp-flexure-head fp-flexure-head-2in 1 choose one output, B (linear alternator): clamps on the 3 in spool, carries flexure stack A\nNone tri-clamp-power-piston piston-2in 1 choose one output, B (linear alternator): full-bore, closed crown (no rod hole: the resonator stays sealed)\nNone tri-clamp-piston-plug fp-piston-plug-2in 1 choose one output, B (linear alternator): in the skirt, carries the tube rod\nNone dowel-pins-metric dowel-3x16 2 choose one output, B (linear alternator): wrist dowels through bosses and plug legs\nNone tube-piston-rods-5mm tube-rod-5x3.4x120 1 choose one output, B (linear alternator): plug to stack B, through stack A and the mover\nNone linear-alternator-mover alt-mover-35-2x8-10x3 1 choose one output, B (linear alternator): on the tube rod, centred in the coils\nNone set-screws-metric set-m3x3 1 choose one output, B (linear alternator): mover hub grub\nNone neodymium-disc-magnets magnet-10x3 16 choose one output, B (linear alternator): row 1 all N out, row 2 all S out\nNone linear-alternator-bobbin alt-bobbin-37-2x10 1 choose one output, B (linear alternator):\nNone linear-alternator-coil alt-coil-bay 2 choose one output, B (linear alternator): one per bay, the second wound the other way\nNone linear-alternator-back-iron-sleeve alt-back-iron-sleeve 1 choose one output, B (linear alternator):\nNone linear-alternator-housing alt-housing-2in-flex80 1 choose one output, B (linear alternator):\nNone linear-alternator-cap-ring alt-cap-2in-flex80 1 choose one output, B (linear alternator):\nNone tri-clamp-flexure-ring fp-flexure-ring-80 1 choose one output, B (linear alternator): carries stack B\nNone spiral-flexure-bearing flexure-80-3arm-w2.5-t2 4 choose one output, B (linear alternator): two per stack, opposite spiral hand\nNone flexure-stack-spacer spacer-80-t2 2 choose one output, B (linear alternator): between the leaf rims\nNone flexure-rim-clamp-plate clamp-plate-80 2 choose one output, B (linear alternator): on each stack's rims\nNone flexure-hub-clamp-washer hub-clamp-80-b5 2 choose one output, B (linear alternator): 2 mm hub washer between the leaf hubs\nNone flexure-hub-collar hub-collar-80-b5 4 choose one output, B (linear alternator): two per stack on the tube rod\nNone threaded-standoffs-metric standoff-m3x15 3 choose one output, B (linear alternator): head to alternator housing\nNone threaded-standoffs-metric standoff-m3x10 3 choose one output, B (linear alternator): alternator cap to the flexure ring\nNone socket-head-cap-screws-metric shcs-m3x20 3 choose one output, B (linear alternator): up through head and stack A into the 15 mm standoffs\nNone socket-head-cap-screws-metric shcs-m3x10 7 choose one output, B (linear alternator): 3 housing base flange, 4 hub-collar pinch screws\nNone socket-head-cap-screws-metric shcs-m3x12 3 choose one output, B (linear alternator): up through the housing's top flange and cap into the 10 mm standoffs\nNone socket-head-cap-screws-metric shcs-m3x16 3 choose one output, B (linear alternator): down through stack B and the ring into the 10 mm standoffs\nNone 2020-aluminum-extrusion 2020-200 8 per stand: two rails on the bench, two uprights\nNone t-slot-corner-brackets corner-bracket-20 8 two per upright, front and back, onto its rail\nNone button-head-screws-metric button-m5x10 16 bracket screws, a washer each\nNone flat-washers-metric washer-m5 16 \nNone drop-in-t-nuts tnut-dropin-20-m5 20 8 per stand for the brackets, 2 per hanger\nNone spool-hanger-collars hanger-2in-tab 2 clamps a spool tube; its bar bolts to both uprights\nNone spool-hanger-collars hanger-2in-plain 2 the other half of each hanger\nNone socket-head-cap-screws-metric shcs-m5x16 4 hanger bar into the uprights' T-nuts\nNone socket-head-cap-screws-metric shcs-m4x20 4 close each hanger on its tube\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Nature (S. Backhaus, G. W. Swift): A thermoacoustic Stirling heat engine, Nature 399, 335–338 (1999) — web — journal article; cited [verify license at link] — https://doi.org/10.1038/20624\n- J. Acoust. Soc. Am. (S. Backhaus, G. W. Swift): A thermoacoustic-Stirling heat engine: Detailed study, JASA 107(6), 3148 (2000): regenerator |Z| 15–30 ρc/A with p and U nearly in phase, thermal buffer tube, inertance and compliance, jet pump against Gedeon streaming — PDF — journal article; numbers cited [verify license at link] — https://sites.science.oregonstate.edu/~hetheriw/energy/topics/doc/thermo/heat_eng/Stirling_engine/thermoacoustic-Stirling.heat.engine.detailed.study.j.acous.soc.2000.pdf\n- G. W. Swift (LANL / Acoustical Society of America): Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Rott's equations, screen relations, DeltaEC) — web, software — LANL [verify license at link] — https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/\n- Phys. Rev. Lett. (T. Yazaki, A. Iwata, T. Maekawa, A. Tominaga): Traveling wave thermoacoustic engine in a looped tube, PRL 81, 3128 (1998) — web — journal article; cited [verify license at link] — https://doi.org/10.1103/PhysRevLett.81.3128\n- Phys. Rev. (H. Levine, J. Schwinger): On the radiation of sound from an unflanged circular pipe, Phys. Rev. 73, 383 (1948): end correction 0.6133 a — web — journal article; cited [verify license at link] — https://doi.org/10.1103/PhysRev.73.383\n- Applied Energy (Z. Yu, A. J. Jaworski, S. Backhaus): Travelling-wave thermoacoustic electricity generator using an ultra-compliant alternator, Applied Energy 99, 135–145 (2012): atmospheric air, a commercial loudspeaker as the alternator, 11.6 W electric — web — journal article; cited [verify license at link] — https://doi.org/10.1016/j.apenergy.2012.04.046\n- Xem Studio: Free-piston Stirling build list and its checked assembly (tools/asm_free-piston-2in.py): the alternator section reused here — web — CC BY 4.0 — https://xemstudio.com/objects/list-free-piston-2in/\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-loop-2in\n", "sources": [ { "publisher": "Nature (S. Backhaus, G. W. Swift)", "title": "A thermoacoustic Stirling heat engine, Nature 399, 335–338 (1999)", "url": "https://doi.org/10.1038/20624", "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): regenerator |Z| 15–30 ρc/A with p and U nearly in phase, thermal buffer tube, inertance and compliance, jet pump against Gedeon streaming", "url": "https://sites.science.oregonstate.edu/~hetheriw/energy/topics/doc/thermo/heat_eng/Stirling_engine/thermoacoustic-Stirling.heat.engine.detailed.study.j.acous.soc.2000.pdf", "formats": [ "PDF" ], "license": "journal article; numbers cited", "license_verified": false, "hosted": false }, { "publisher": "G. W. Swift (LANL / Acoustical Society of America)", "title": "Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Rott's equations, screen relations, DeltaEC)", "url": "https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/", "formats": [ "web", "software" ], "license": "LANL", "license_verified": false, "hosted": false }, { "publisher": "Phys. Rev. Lett. (T. Yazaki, A. Iwata, T. Maekawa, A. Tominaga)", "title": "Traveling wave thermoacoustic engine in a looped tube, PRL 81, 3128 (1998)", "url": "https://doi.org/10.1103/PhysRevLett.81.3128", "formats": [ "web" ], "license": "journal article; cited", "license_verified": false, "hosted": false }, { "publisher": "Phys. Rev. (H. Levine, J. Schwinger)", "title": "On the radiation of sound from an unflanged circular pipe, Phys. Rev. 73, 383 (1948): end correction 0.6133 a", "url": "https://doi.org/10.1103/PhysRev.73.383", "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, Applied Energy 99, 135–145 (2012): atmospheric air, a commercial loudspeaker as the alternator, 11.6 W electric", "url": "https://doi.org/10.1016/j.apenergy.2012.04.046", "formats": [ "web" ], "license": "journal article; cited", "license_verified": false, "hosted": false }, { "publisher": "Xem Studio", "title": "Free-piston Stirling build list and its checked assembly (tools/asm_free-piston-2in.py): the alternator section reused here", "url": "https://xemstudio.com/objects/list-free-piston-2in/", "formats": [ "web" ], "license": "CC BY 4.0", "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": [ "thermoacoustic-hot-shroud", "thermoacoustic-water-jacket", "thermoacoustic-bore-spacer", "thermoacoustic-heat-exchanger", "regenerator-cage", "regenerator-mesh-disc", "sanitary-clamp-elbows", "sanitary-clamp-tees", "tri-clamp-torch-stand", "thermoacoustic-driver-cap", "loudspeaker-envelope-40mm", "linear-alternator-mover", "tri-clamp-flexure-head", "tri-clamp-diaphragm-membrane", "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": "What frequency does it run at?", "a": "78 parts, every one a free STEP/STL on this site; see the table and the build order on this page." }, { "q": "How hot does it need to get?", "a": "The model starts it at about 184 °C at the hot exchanger with the loudspeaker (179 °C with the alternator); I expect the real engine to need more, perhaps 250–350 °C." }, { "q": "Why is the core vertical with the hot end up?", "a": "So the thermal buffer tube has hot gas over cold gas and does not convect; the flame shroud and flue bring the torch to it." }, { "q": "Do I need the water jackets?", "a": "No. They are optional heat exchangers clamped on the plain spool; without them the ambient exchangers warm up and the engine needs more heat to start. Any cooling of those bands works, even a wet rag." }, { "q": "Which output should I build?", "a": "The loudspeaker (A): milliwatts to a fraction of a watt from the 40 mm speaker by my estimate, and a bigger matched speaker is the upgrade. The linear alternator (B) fits exactly, but at this frequency its piston hardly moves." }, { "q": "What does the membrane do?", "a": "It blocks the steady flow round the loop (Gedeon streaming) that otherwise carries heat from the hot exchanger to the ambient one; Backhaus & Swift used a jet pump for the same job." } ], "files_license": null, "offers": [], "markdown": "https://xemstudio.com/objects/list-ta-loop-2in/index.md" }