Annular regenerator screen stack, Ø48 / Ø42 × 40 (50 mesh × 0.22 mm wire) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/stirling-annular-screen-stack/  (CC BY 4.0)
Basis: Porosity of stacked square-weave screens 1 − π m d / 4; friction and heat transfer from the Urieli & Berchowitz screen correlations
Catalog version: 2026-10-20

Sizes: see table below
- Annular screens punched Ø48.00 outside, Ø42.00 inside, stacked 40 mm deep on the liner's neck: about 91 screens of 50 mesh (per inch) × 0.22 mm wire, porosity 0.660, hydraulic diameter 0.43 mm.
- Gas volume in the stack 11.2 mL. In the cycle model its effectiveness is 0.966 on charged air at 600 rpm and 0.980 on helium at 1200 rpm.
- Finer screens raise the effectiveness and the pumping loss together; I swept 0.10 to 0.30 mm wire and 0.22 mm was the best shaft power on air and on helium.

item  value
envelope  Ø48.00 / Ø42.00 × 40
screen  50 mesh × 0.22 wire
count  ≈ 91
porosity  0.66

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Ohio University (I. Urieli): Stirling cycle machine analysis (after Urieli & Berchowitz, Stirling Cycle Engine Analysis, 1984): Schmidt and simple analyses, wire-screen regenerator friction fr = 54 + 1.43 Re^0.78 and St = 0.46 Re^−0.4 / Pr — web — university course pages [verify license at link] — https://www.ohio.edu/mechanical/stirling/
- NASA (W. R. Martini): Stirling Engine Design Manual, 2nd edition, NASA CR-168088 (1983): decoupled second-order losses (shuttle, conduction, flow friction, regenerator) — PDF — US government report — https://ntrs.nasa.gov/citations/19830022057
- Cambridge University Press (J. R. Senft): Mechanical Efficiency of Heat Engines (2007): shaft work = E·W − (1/E − E)·W_forced — book — book; formula cited [verify license at link] — https://doi.org/10.1017/CBO9780511546105
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/stirling-annular-screen-stack/index.json
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