Double-Acting Steam Engine
Steam Engine Lab · structural repair v1.1
EN
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Only geometry and port openings are scrubbed. Pressures and flow arrows are hidden. Exit restores the untouched physical state.
One state. Connected mechanisms.
The shaft drives the piston linkage, eccentric and governor together. Try adding load, then disconnect the governor and repeat. The speed readout includes real cycle-to-cycle ripple.
Flattened section: horizontal dimensions follow the model; depth is expanded. A/B: cylinder chambers. E: central exhaust.
Reconstructed mechanism with ideal-gas steam, assumed governor parameters and ideal joints. No condensation, boiler dynamics or manufacturing-grade contact analysis.
Model, assumptions and sources
A reconstruction of the Powerhouse B1633 architecture. Bore 127 mm; stroke 177.8 mm; connecting rod 340 mm; flywheel diameter 762 mm. Some dimensions and governor internals are engineering assumptions, not surveyed museum CAD.
One fixed-step state couples gas mass and energy, crank torque, shaft inertia and the spring-loaded governor. The D-slide follows an 18 mm eccentric with 35° advance, 9 mm steam lap and 1 mm exhaust lap. The governor changes supply area, not valve timing.
The energy ledger includes reservoir enthalpy, brake work, friction, atmospheric work, spring and gravity energy, explicit hand-start impulses and inelastic stop losses. Cutting off steam retains stored energy. RK4 uses a fixed 0.25 ms step; playback changes the number of steps, never their size.
Dry ideal-gas steam surrogate: no condensation, steam tables, wall heat transfer, leakage or boiler dynamics. Gear contact, pump hydraulics and structural flexibility are omitted. Use this model to study timing and qualitative feedback, not to size or certify machinery.
Scrubbing changes geometry and port openings only. Pressure and flow claims are hidden; the physical state is preserved. The source operating checks focus on 345 kPa gauge and loads around 30 N·m, not the entire 0–500 kPa / 0–110 N·m control range.
Technical references supplied with the model
- Powerhouse Collection — B1633
- John Bourne — A Catechism of the Steam Engine
- James Clerk Maxwell — On Governors (1868)
- NASA Glenn — Mass Flow Choking
Validation and evidence limits
The supplied structural repair v1.1 rebuilds the crank stack, bored crosshead fork, guide shoes, pressure passages, governor joints, bearing supports and pump takeoff. Nominal crosshead clearances are 0.20 mm; ideal joints do not solve contact forces or clearance take-up.
Numerical checks cover fixed-step integration, conservation accounting, valve openings, crank closure, dead-centre starting and load response. The live energy residual and CSV trace are available in Data. These are model checks, not measurements of a physical engine.
The original file contains author-reported structural and numerical test tables. Those reference results are not a live test or independent certification. The integration checks and source fingerprint are recorded in the exhibit documentation; they do not certify manufacture or safe operation.
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