Water wheel

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Agricola1

File:Otley waterwheel, Manchester Museum of Science and Industry - 2017-03-17 - Andy Mabbett.flac

Vertical waterwheel simple

Stream waterwheel simple

Undershot waterwheel simple

Water wheel

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. Water wheels were still in commercial use well into the 20th century but they are no longer in common use.

History

The water wheel is an ancient device that predates the Roman Empire. Water wheels have been used for thousands of years for industrial purposes, especially in Europe, Asia, and North America. The earliest clear description of a water wheel is from the 1st century BC, with the technology spreading across the Roman Empire. The use of water wheels significantly contributed to the advancement of technology and society, enabling the development of industries such as milling, lumber, and textile production.

Types of Water Wheels

There are three main types of water wheels: horizontal water wheels, undershot vertical water wheels, and overshot vertical water wheels.

Horizontal Water Wheels

Horizontal water wheels lie flat on the water, with the water passing underneath to turn the wheel. These are one of the oldest types of water wheels.

Undershot Water Wheels

In an undershot water wheel, the water hits the wheel at the bottom. This type of wheel is typically installed in fast-moving streams.

Overshot Water Wheels

Overshot water wheels receive water from above, often from a millrace or weir. This type of water wheel is the most efficient, as it can utilize the gravitational force of the falling water to a greater extent.

Mechanics and Uses

The basic mechanism involves water hitting the water wheel, causing it to turn. The rotational motion is then converted into mechanical energy that can be used for various industrial processes. Historically, water wheels have been used to power different types of mills (such as grain mills, sawmills, and textile mills), to pump water, and to power machinery in workshops.

Decline and Legacy

The advent of steam power and later electrical power led to the decline of the water wheel as a major source of industrial power. However, water wheels have seen a resurgence in some areas for small-scale hydroelectric power generation, as well as for historical preservation and educational purposes.

Environmental Impact

Water wheels are considered a renewable energy source and have a low environmental impact compared to fossil fuels. They do not emit greenhouse gases or pollutants. However, their installation and operation can affect local aquatic ecosystems and water flow.