Spiral on a cylinder
A spiral wound round a cylinder to convert the motion of the wind or a stream of water into rotary motion.
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 side, as Brown, gravity on. A cylinder with one turn of spiral blade wound round it turns freely between two posts on a level shaft (light bearing friction). The stream is the only input: particle water enters all round at the right-hand post and flows along the drum to the left, using the ring water about x added on this branch (openspec add-ring-water-axis). There is no motor; the torque driver is held at zero.
- Measured
- The water presses on the slanting blade and turns the cylinder steadily at about 4.4 rad/s, in the direction the slant gives. The water is drawn from the particles, as short faint drops round the drum so the cylinder and spiral show. The motion gate passes.
- Notes
- Grade B. The drum is taken as lying deep in the stream (water all round), since the ring water has no gravity across the shaft. WARN: about 6% of the water leaves the domain at the ends.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
