Volute wheel, having radial vanes, a, against which the water…
Volute wheel, having radial vanes, a, against which the water impinges and carries the wheel around. The scroll or volute casing, b, confines the water in such a manner that it acts against the vanes all around the wheel. By the addition of the inclined buckets, c, c, at the bottom, the water is made to act with additional force as it escapes through the openings of said buckets.
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
- Brown's plan view from above, gravity on. The water runs along a straight, nearly level inlet at the top of the casing and over a rounded edge falling 1.9 cm (about 0.6 m/s) into the scroll or volute casing (b), whose wall closes in from 16.6 cm to 13.2 cm round the wheel, ending in a rounded tongue beside the inlet. The water runs clockwise round the scroll and strikes the wheel's 8 radial vanes (a), which stand from 7 to 12 cm out, just clear of the casing's floor and rounded at both ends. The floor falls inwards at 20 degrees to a round opening (4.4 cm) in the middle with a rounded lip. Below the opening the wheel carries 4 inclined buckets (c) on its hub, which the water falls through and leaves leaning anticlockwise, pushing the wheel on clockwise. The water is 220 parcels, each a smooth ball 0.9 cm across at 1 g/cm³. They start at rest in the inlet, spread so that they reach the edge at a steady rate from 0.2 s to 9.5 s. Each parcel moves freely in space (three slides) and touches the inlet, casing, vanes and buckets but not other parcels. The water is the only input. Nothing is driven (there is a zero-torque driver), and the shaft works against a load (0.0002 N m s).
- Measured
- The first water reaches the vanes at about 2.2 s. From rest the wheel turns clockwise seen from above, as Brown's arrow shows, at about 2 to 3 rad/s while the water runs, never running back. The water runs round the scroll and down the floor, through the buckets and out underneath. Contact penetration stays within 0.8 mm.
- Notes
- The water is modelled as separate parcels that do not touch one another. Its head is a short fall over the inlet's edge rather than the pressure of a full supply, and the parcels are released from rest in the inlet rather than supplied continuously. Brown's inlet is a short stub at the top; here it is a longer straight channel along the top so the water can be laid out in it. The bolting flanges round the casing are left out.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
