Common wind-mill, illustrating the production of circular motion…
Common wind-mill, illustrating the production of circular motion by the direct action of the wind upon the oblique sails.
Only the input is driven; every other part of this model moves by physics (MuJoCo), and its ratios are measured. Run it live, change its parameters, or switch the friction off to see the output stop.
- Modelled as
- Seen from the front quarter, as Brown, gravity on. A round tower with a dome cap and a tail vane; four sails, 23 cm long, on a shaft along the wind out of the cap, each slanted 18 degrees out of the plane it turns in. The wind (2.5 m/s along the shaft) is the only input: MuJoCo's fluid forces (openspec add-air-wind: the medium in `<option>`, the ellipsoid model fitted to each sail) push on the sails; the shaft works against the millstones' load (0.003 N m s). Nothing is driven.
- Measured
- From rest the sails pick up and settle at about 5.8 rad/s, the way their slant gives (tests/test_air.py: still air leaves them at rest, a wind from the other side turns them back). The motion gate passes with no flags.
- Notes
- Grade B+. The air is not drawn (Brown draws none); the sails' lattice is drawn as whips and bars on the cloth.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
