Military applications
Kites have been used for military uses in the past for signaling, for delivery of munitions, and for observation, by lifting an observer above the field of battle, and by using kite aerial photography.
Kim Yu-Sin (or Kim Yushin), a Korean general, in 637 C.E. rallied his troops to defeat rebels by kite lofting a burning ball. Kites were also used by Admiral Yi of the Joseon (1392-1910) Dynasty of Korea. During the Japanese invasions of Korea (1592-1598), Admiral Yi commanded his navy with kites. His kites had specific markings directing his fleet to perform his order. Admiral Yi was said to have over 300 such kites. The war eventually resulted in a Chinese and Korean victory; the kites played a minor role in the war's conclusion.
In more modern times the British navy also used kites to haul human lookouts high into the air to see over the horizon and possibly the enemy ships, for example with the kite developed by Samuel Franklin Cody. Barrage kites were used to protect London as well as the Pacific coast of the United States during the last century. Kites and kytoons were used for lofting communications antenna. Submarines lofted observers in rotary kites. The Rogallo parawing kite and the Jalbert parafoil kite were used for governable parachutes (free-flying kites) to deliver troops and supplies.
Science and meteorology
Kites have been used for scientific purposes, such as Benjamin Franklin's famous experiment proving that lightning is electricity. Kites were the precursors to aircraft, and were instrumental in the development of early flying craft. Alexander Graham Bell experimented with very large man-lifting kites, as did the Wright brothers and Lawrence Hargrave. Kites had an historical role in lifting scientific instruments to measure atmospheric conditions for weather forecasting.
Radio aerials and light beacons
Kites can be used for radio purposes, by kites carrying antennas for MF, LF or VLF-transmitters. This method was used for the reception station of the first transatlantic transmission by Marconi. Captive balloons may be more convenient for such experiments, because kite-carried antennas require a lot of wind, which may be not always possible with heavy equipment and a ground conductor. It must be taken into account during experiments, that a conductor carried by a kite can lead to a high voltage toward ground, which can endanger people and equipment, if suitable precautions (grounding through resistors or a parallel resonant-circuit tuned to transmission frequency) are not taken.
Kites can be used to carry light effects such as lightsticks or battery powered lights.
Kite traction
Kites can be used to pull people and vehicles downwind. Efficient foil-type kites such as power kites can also be used to sail upwind under the same principles as used by other sailing craft, provided that lateral forces on the ground or in the water are redirected as with the keels, center boards, wheels and ice blades of traditional sailing craft. In the last two decades several kite sailing sports have become popular, such as kite buggying, kite landboarding and kite surfing. Snow kiting has also become popular in recent years.
Kite sailing opens several possibilities not available in traditional sailing:
* Wind speeds are greater at higher altitudes
* Kites may be manoeuvered dynamically which increases the force available dramatically
* There is no need for mechanical structures to withstand bending forces; vehicles or hulls can be very light or dispensed with all together
The German company SkySails has developed ship-pulling kites as a supplemental power source for cargo ships, first tested in January 2008 on the ship MS Beluga Skysails. Trials on this 55 m ship have shown that, in favorable winds, the kite reduces fuel consumption by up to 30%. This system is planned to be in full commercial production late 2008. Kites are available as an auxiliary sail or emergency spinnaker for sailing boats. Self-launching Parafoil kites are attached to the mast.
MS Beluga Skysails is the world's first commercial container cargo ship partially powered by a giant computer-controlled kite (160 m² or 1,722 sq ft). The kite could reduce fuel consumption by 20%. It was launched on 17 December 2007 and was set to leave the northern German port of Bremerhaven to Guanta, Venezuela on January 22, 2008. Stephan Wrage, managing director of SkySails GmbH announced: "During the next few months we will finally be able to prove that our technology works in practice and significantly reduces fuel consumption and emissions." Verena Frank, project manager at Beluga Shipping GmbH, SkySails GmbH's partner further stated that "the project's core concept was using wind energy as auxiliary propulsion power and using wind as a free of charge energy".
Power generation
A conceptual research and development project by Makani Power, based in California and funded by Google.org, is investigating the use of kites in harnessing high altitude wind currents to generate electricity.
A separate Delft University of Technology project has used a 10 m² kite to generate 10 kilowatts of power.
See also laddermill.
Kites have been used for military uses in the past for signaling, for delivery of munitions, and for observation, by lifting an observer above the field of battle, and by using kite aerial photography.
Kim Yu-Sin (or Kim Yushin), a Korean general, in 637 C.E. rallied his troops to defeat rebels by kite lofting a burning ball. Kites were also used by Admiral Yi of the Joseon (1392-1910) Dynasty of Korea. During the Japanese invasions of Korea (1592-1598), Admiral Yi commanded his navy with kites. His kites had specific markings directing his fleet to perform his order. Admiral Yi was said to have over 300 such kites. The war eventually resulted in a Chinese and Korean victory; the kites played a minor role in the war's conclusion.
In more modern times the British navy also used kites to haul human lookouts high into the air to see over the horizon and possibly the enemy ships, for example with the kite developed by Samuel Franklin Cody. Barrage kites were used to protect London as well as the Pacific coast of the United States during the last century. Kites and kytoons were used for lofting communications antenna. Submarines lofted observers in rotary kites. The Rogallo parawing kite and the Jalbert parafoil kite were used for governable parachutes (free-flying kites) to deliver troops and supplies.
Science and meteorology
Kites have been used for scientific purposes, such as Benjamin Franklin's famous experiment proving that lightning is electricity. Kites were the precursors to aircraft, and were instrumental in the development of early flying craft. Alexander Graham Bell experimented with very large man-lifting kites, as did the Wright brothers and Lawrence Hargrave. Kites had an historical role in lifting scientific instruments to measure atmospheric conditions for weather forecasting.
Radio aerials and light beacons
Kites can be used for radio purposes, by kites carrying antennas for MF, LF or VLF-transmitters. This method was used for the reception station of the first transatlantic transmission by Marconi. Captive balloons may be more convenient for such experiments, because kite-carried antennas require a lot of wind, which may be not always possible with heavy equipment and a ground conductor. It must be taken into account during experiments, that a conductor carried by a kite can lead to a high voltage toward ground, which can endanger people and equipment, if suitable precautions (grounding through resistors or a parallel resonant-circuit tuned to transmission frequency) are not taken.
Kites can be used to carry light effects such as lightsticks or battery powered lights.
Kite traction
Kites can be used to pull people and vehicles downwind. Efficient foil-type kites such as power kites can also be used to sail upwind under the same principles as used by other sailing craft, provided that lateral forces on the ground or in the water are redirected as with the keels, center boards, wheels and ice blades of traditional sailing craft. In the last two decades several kite sailing sports have become popular, such as kite buggying, kite landboarding and kite surfing. Snow kiting has also become popular in recent years.
Kite sailing opens several possibilities not available in traditional sailing:
* Wind speeds are greater at higher altitudes
* Kites may be manoeuvered dynamically which increases the force available dramatically
* There is no need for mechanical structures to withstand bending forces; vehicles or hulls can be very light or dispensed with all together
The German company SkySails has developed ship-pulling kites as a supplemental power source for cargo ships, first tested in January 2008 on the ship MS Beluga Skysails. Trials on this 55 m ship have shown that, in favorable winds, the kite reduces fuel consumption by up to 30%. This system is planned to be in full commercial production late 2008. Kites are available as an auxiliary sail or emergency spinnaker for sailing boats. Self-launching Parafoil kites are attached to the mast.
MS Beluga Skysails is the world's first commercial container cargo ship partially powered by a giant computer-controlled kite (160 m² or 1,722 sq ft). The kite could reduce fuel consumption by 20%. It was launched on 17 December 2007 and was set to leave the northern German port of Bremerhaven to Guanta, Venezuela on January 22, 2008. Stephan Wrage, managing director of SkySails GmbH announced: "During the next few months we will finally be able to prove that our technology works in practice and significantly reduces fuel consumption and emissions." Verena Frank, project manager at Beluga Shipping GmbH, SkySails GmbH's partner further stated that "the project's core concept was using wind energy as auxiliary propulsion power and using wind as a free of charge energy".
Power generation
A conceptual research and development project by Makani Power, based in California and funded by Google.org, is investigating the use of kites in harnessing high altitude wind currents to generate electricity.
A separate Delft University of Technology project has used a 10 m² kite to generate 10 kilowatts of power.
See also laddermill.
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