Thermoacoustic buffer-tube liner: 2 in, 0.5 wall, 180 and 140 mm — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/thermoacoustic-buffer-tube-liner/  (CC BY 4.0)
Basis: Bore Ø47.5; lengths from the core layouts in tools/gen_ta_power.py
Catalog version: 2026-10-20

Sizes: see table below
- The thermal buffer tube is the open length between the hot exchanger and the secondary ambient exchanger: the gas oscillates in it without touching anything, so the heat stays at the hot end. It runs hot end up (hot gas over cold), so it does not convect.
- The liner is what the hot exchanger stands on: a thin tube at the bore, 0.5 wall, so it conducts as little heat as it can (the model counts its conduction with the tube wall's).
- 180 mm in the ring engine's cores, 140 mm in the twin engine's: in the model the ring's gas moves about ±9 mm at the liner's ends, well inside its length.
- Fit: outside slide in the bore; the ends bear on the exchanger inserts.

file  outside_mm  inside_mm  length_mm
tbt-liner-2in-140  47.5  46.5  140.0
tbt-liner-2in-180  47.5  46.5  180.0

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 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
- 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/
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/thermoacoustic-buffer-tube-liner/index.json
API: https://xemstudio.com/api/geometry?object=thermoacoustic-buffer-tube-liner