A Water Wheel, the Lake of the Ipiranga Creek Springs, the Botanical Garden of São Paulo, Brazil.
The lake is formed by some of the water springs of the Ipiranga Creek, found in the biological reserve of State Park of Ipiranga.
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets arranged on the outside rim forming the driving surface.
Vertical wheel with horizontal axle;
The water hits near the top of the wheel and in front of the axle so that it turns away from the head race;
Driving surfaces – buckets;
Water – low volume, large head;
Efficiency – 80 to 90%;
Overshot and backshot water wheels are typically used where the available height difference is more than a couple of meters. Breastshot wheels are more suited to large flows with a moderate head. Undershot and stream wheel use large flows at little or no head.
There is often an associated millpond, a reservoir for storing water and hence energy until it is needed. Larger heads store more potential energy for the same amount of water so the reservoirs for overshot and backshot wheels tend to be smaller than for breast shot wheels.
Overshot and pitchback water wheels are suitable where there is a small stream with a height difference of more than 2 meters, often in association with a small reservoir. Breastshot and undershot wheels can be used on rivers or high volume flows with large reservoirs.