Tympanum

A model of the roman Tympanum, in the cutaway, you can see the exposed spiral paddles. Their curvature is key to creating a path for the water to continuously flow to a local low point despite being raised by the wheel's rotation.

The Tympanum is a water wheel that not only produces mechanical energy as the rotation of it's shaft, but also lifts water to higher elevations. The Tympanum dates back to the Roman empire, where it was used to feed water from rivers and streams into aqueducts and cisterns. It was usually used to move water that was already running, so that it rotated without any outside energy input, but it can also be turned by man or animal power if the water is coming from a still source, such as a lake or pond. The tympanum is at it's heart a water wheel with the paddles fully enclosed between two planes, and a hollow shaft at the middle that allows water to flow through it. As the water flows past the wheel, and the wheel turns, the curved paddles "scoop" the water out and raise it by means of rotation. Once the compartment is above the central shaft, the water then flows towards the lowest point, which is the hollow shaft, and out to whatever pipe or storage awaits it. Some limitations of the tympanum are that it can only raise water to an elevation just under half it's total diameter, requires a running water source to power it, and cannot capture all the flow of it's source water unless it is powered by means other than flow.

Dependencies

• Water
• Wheel
  • Tympanum
    • Energy

See also

• Screw
• Simple Machines