Wake

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For other uses, see Wake (disambiguation).

The wake of a slow moving boat

The wakes of two slow-moving boats. The nearer boat has made a striking series of ruler-straight waves

A wake is the region of turbulence immediately to the rear of a solid body caused by the flow of air or water around the body.

In fluid dynamics, a wake is the region of turbulence around a solid body moving relative to the water, caused by the flow of liquid around the body. The wake leading the body is caused by the compression of the liquid medium by the moving body, and is often called a bow wake when observed preceding a watercraft. As with all wave forms, it spreads outward from the source until its energy is overcome or lost, usually by friction or dispersion.

Wakes are occasionally used recreationally. Swimmers, people riding personal watercraft, and aquatic mammals such as dolphins, can ride the leading edge of a wake. In the sport of water polo, the ball carrier can swim while advancing the ball, propelled ahead with the wake created by alternating armstrokes, a technique known as dribbling.

[edit] Gallery

Wake behind a ferry (Baltic Sea)

Wave cloud pattern in the wake of the Île Amsterdam (lower left, at the "tip" of the triangular formation of clouds) in the southern Indian Ocean

At closer spacing, there are three types of flow:
1. Isolated roughness Flow - The wides of buildings are big enough, and buildings are not significantly interact, the wakes are disturbed.
2. Wake interference Flow - There is secondary flow in the canyon space, downward flow of the cavity eddy is reinforced by the deflection down the windward face of the next building downstream.
3. Skimming Flow - A stable circulatory vortex is established in the canyon. Bulk of the flow does not enter the canyon.