Power kite

A power kite or traction kite is a large kite designed to provide significant pull to the user.

Their two most common forms are the foil, and the leading edge inflatable. There are also other less common types of power kite including rigid-framed kites and soft single skin kites. There are several different control systems used with these kites which have two to five lines and a bar or handles.

Foil kites consist of a number of cells with cloth ribs in each cell. It is the profile of these ribs that gives the kite its aerofoil shape and enable it to generate lift. The most common type is the ram-air foil, where each cell has a gauze-covered opening at the front, meaning air is forced in during flight, giving the kite its stiffness and enabling it to hold its profile. Some ram-air foils are closed-cell, where a one-way valve locks the air inside the cells, giving some increased water relaunch capability.

Leading edge inflatable kites (LEIs) are made of a single skin of fabric with, as the name suggests, an inflated tubular leading edge and inflated ribs. The leading edge and ribs are inflated by the user with a pump prior to launching the kite. The profile of an LEI type kite comes from the inflatable edge and ribs. LEI kites are primarily used for kitesurfing, as they retain their structure when wet and can be easily relaunched from the water after sitting on the surface for an extended period. Conversely, an open-celled foil kite crashed into the sea immediately becomes saturated with water and unflyable.

Power kites are generally used in conjunction with a vehicle or board, such as in:

Power kites can also be used recreationally without a vehicle or board, as in kite jumping or kite man lifting, where a harnessed kite flier is moored to the ground or one or more people to provide tension and lift

Research is also under way in the use of kites to generate electric power to be fed into a power grid.Laddermills are a type of airborne wind turbine. Kites are used to reach high altitude winds such as a jet stream, which are always present, even if ground level winds available to wind turbines are absent.

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Wikipedia