HISTORICAL DRAWING · Drawing published 1878

Separate-condenser engine

What shaft power follows from an assumed mean effective pressure?

Boulton & Watt double-acting engine (1784 design): beam, separate condenser and air pump, sun-and-planet gear, governor
Boulton & Watt double-acting engine (1784 design): beam, separate condenser and air pump, sun-and-planet gear, governor. View the original source and attribution ↗

A contemporary sketch model

Every number below is a modern illustrative assumption. The historical drawing supplies a question; the source model is an exercise in reasoning about it.

pressure = 150 kPa in 100..200 ± 10% "Assumed mean effective pressure"
swept = 0.01 m^3 "Assumed swept volume per working stroke"
strokes = 2 Hz "Power strokes per second, not shaft rpm"
efficiency = 0.8 "Assumed mechanical efficiency"
work := pressure*swept [J]
shaftPower := work*strokes*efficiency [W]
check output: shaftPower >= 2000 W
sweep Pressure: pressure = 100, 150, 200 kPa

Model limits

Not a steam cycle or condenser heat-transfer model. Mean effective pressure must come from evidence.

Explore it with your agent

Create a Study, inspect the installed capabilities, and use this source as a starting point. Ask the agent to explain the equations and assumptions, then replace illustrative inputs with measured evidence for your own design.

This example includes a scalar sweep. Use napkin_sketch to add the model and napkin_run to inspect the sweep; the source editor’s scalar comparison view is for simple scenarios.

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