Hiscox item 340 depicts the Ritter rotary engine as a concentric revolving cylinder with an abutting lip. A geared revolving lunette opens a passage for the lip, while a continuous gear train operates the valve.
Ritter Rotary Engine Interactive Calculator
Explore ideal constant-mean-pressure work for a selected effective swept volume while viewing the historical Ritter topology.
Equation Used
- Selected mean effective pressure is constant over the entered effective sweep.
- Projected working-face area and effective sweep define one event volume.
- The active-face count sets ideal work events per revolution.
- Admission, expansion history, timing, leakage, friction, efficiency, stresses and ratings are excluded.
The secondary figure shows the same historical topology and selected ideal indicated-power result.
How the historical Ritter arrangement works
A cylinder revolves concentrically inside the outer shell and carries an abutting lip or extension that fits the case. A separate revolving lunette is geared to the main shaft so the lip can pass it. Hiscox also shows an exterior view with the continuous gear train that operates the valve.
This differs from the removed page's description of a radial vane passing a cam-retracted sliding abutment. The animation follows the identifiable elements in the historical figure without inventing exact gear tooth counts, port timing or seal construction.
What this calculator demonstrates
Select mean effective pressure, projected working-face area, effective working sweep, active faces per revolution and speed. The calculator returns ideal pressure-volume work per event, swept volume per revolution, ideal indicated power and ideal mean torque.
It does not predict live-steam admission, expansion history, cut-off, condensation, leakage, lunette or valve timing, friction, mechanical efficiency, delivered shaft power, stresses, temperature, lubrication, wear or ratings.
Bounded ideal pressure-work model
For constant selected mean effective pressure p, projected working-face area A and effective sweep L, swept volume per event is Ve = AL and ideal work per event is We = pVe. With k active faces per revolution and speed N rpm, ideal indicated power is Pi = WekN/60.
Swept volume per revolution is kAL. Ideal mean torque is Ti = Pi/ω with ω = 2πN/60. These are constant-mean-pressure bookkeeping quantities, not a steam-cycle or delivered-power prediction.
Default selected example
For p = 310 kPa, A = 22.5 cm², L = 0.675 m, one active face per revolution and N = 250 rpm, ideal work per event is 470.8 J, swept volume is 1.519 L/rev, indicated power is 1.962 kW and ideal mean torque is 74.93 N·m.
No mechanical efficiency is supplied, so delivered shaft power and torque cannot be inferred.
Scope and correction boundary
Hiscox is the identified historical source for the Ritter topology. The removed article instead described a different sliding-abutment vane mechanism and supplied precise clearances, loss percentages, timing, speeds, service diagnoses and provenance without corresponding evidence.
MIT thermodynamics references support pressure-volume work. Applying a single mean effective pressure across a selected effective swept volume is an ideal indicated-work model only; a real indicator diagram and measured losses are needed for performance.
Questions
Is the lunette a sliding abutment?
No. Hiscox calls it a revolving lunette controlled by gearing on the main shaft.
Does the selected pressure equal supply pressure?
Not necessarily. It is a user-selected mean effective pressure representing average indicated pressure over the chosen effective sweep.
Is indicated power delivered shaft power?
No. Mechanical friction, leakage and other losses separate indicated work from delivered shaft work.
Does the animation reproduce exact Ritter valve timing?
No. The historical source identifies the components and continuous gearing but does not supply the complete dimensions and tooth counts needed for a reconstruction.
Primary technical references
- G. D. Hiscox, Mechanical Movements, Powers, Devices and Appliances — item 340 identifies the concentric revolving cylinder, abutting lip, geared revolving lunette and continuous valve gear.
- MIT OpenCourseWare, Lectures on Thermodynamics — pressure-volume boundary work relation.
- MIT Unified Engineering Thermodynamics, Chapter 4 — force as pressure times area and mechanical work over displacement.
- NIST Guide to the SI — SI dimensions for pascal, joule and power quantities.
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