A kite is a tethered aircraft.[1] The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind. The resultant force vector from the lift and drag force components is opposed by the tension of the one or more lines or tethers.[2] The anchor point of the kite line may be static or moving (e.g., the towing of a kite by a running person, boat, free-falling anchors as in paragliders and fugitive parakites [3][4] or vehicle).[5][6]
The same principles can be used in water[7][8][9] and experiments have also been made with lighter-than-air kites (kytoons) [10]
Kites may be flown for recreation, art or other practical uses. Sport kites can be flown in aerial ballet, sometimes as part of a competition. Power kites are multi-line steerable kites designed to generate large forces which can be used to power activities such as kite surfing, kite landboarding, kite fishing, kite buggying and a new trend snow kiting. Kites towed behind boats can lift passengers[11] which has had useful military applications in the past.[12]
It is generally accepted that kites were first developed in approximately 2,800 years ago in China,[13][14] where materials ideal for kite building were readily available: silk fabric for sail material; fine, high-tensile-strength silk for flying line; and resilient bamboo for a strong, lightweight framework.
The kite was said to be the invention of the famous 5th century BC Chinese philosophers Mozi and Lu Ban. By at least 549 AD paper kites were being flown, as it was recorded in that year a paper kite was used as a message for a rescue mission.[15] Ancient and medieval Chinese sources list other uses of kites for measuring distances, testing the wind, lifting men, signalling, and communication for military operations.[15] The earliest known Chinese kites were flat (not bowed) and often rectangular. Later, tailless kites incorporated a stabilizing bowline. Kites were decorated with mythological motifs and legendary figures; some were fitted with strings and whistles to make musical sounds while flying.[16][17][18]
The kite further evolved into the fighter kite known as the patang in India where thousands are flown every year on festivals such as Makar Sankranti.[19]
Kites were know throughout Polynesia, as far as New Zealand, with the assumption being that the knowledge diffused from China along with the people. Anthropomorphic kites made from cloth and wood were used in religious ceremonies to send prayers to the gods.[20] Polynesian kite traditions are used by anthropologists get an idea of early "primitive" Asian traditions that are believed to have at one time existed in Asia.[21]
Kites were late to arrive in Europe, although windsock-like banners known and used by the Romans. Stories of kites were first brought to Europe by Marco Polo towards the end of the 13th century, and kites were brought back by sailors from Japan and Malaysia in the 16th and 17th centuries.[22] Although they were initially regarded as mere curiosities, but by the 18th and 19th centuries kites were being used as vehicles for scientific research.[22]
In 1750, Benjamin Franklin published a proposal for an experiment to prove that lightning is electricity by flying a kite in a storm that appeared capable of becoming a lightning storm. It is not known whether Franklin ever performed his experiment,[23][24] but on May 10, 1752, Thomas-François Dalibard of France conducted a similar experiment (using a 40-foot (12 m) iron rod instead of a kite) and extracted electrical sparks from a cloud.[23]
Kites were also instrumental in the research and development of the Wright brothers when building the first airplane in the late 1800s. Over the next 70 years, many new kite designs were developed, and often patented. These included Eddy's tail-less diamond kite, the tetrahedral kite, the flexible kite, the sled kite, and the parafoil kite, which helped to develop the modern hang-gliders.[25] In fact, the period from 1860 to about 1910 became the "golden age of kiting". Kites started to be used for scientific purposes, especially in meteorology, aeronautics, wireless communications and photography; many different designs of man-lifting kite were developed as well as power kites. Invention of powered airplane diminished interest in kites. World War II saw a limited use of kites for military purposes (see Focke Achgelis Fa 330 for example). Since then they are used mainly for recreation due to a vast improvement in technology.
Designs often emulate flying insects, birds, and other beasts, both real and mythical. The finest Chinese kites are made from split bamboo (usually golden bamboo), covered with silk, and hand painted. On larger kites, clever hinges and latches allow the kite to be disassembled and compactly folded for storage or transport. Cheaper mass-produced kites are often made from printed polyester rather than silk.
Tails are used for some single-line kite designs to keep the kite's nose pointing into the wind. Spinners and spinsocks can be attached to the flying line for visual effect. There are rotating wind socks which spin like a turbine. On large display kites these tails, spinners and spinsocks can be 50 feet (15 m) long or more.
Modern acrobatic kites use two or four lines to allow fine control of the kite's angle to the wind. Traction kites may have an additional line to de-power the kite and quick-release mechanisms to disengage flyer and kite in an emergency.
Chinese dragon kite more than one hundred feet long which flew in the annual
Berkeley, California, kite festival in 2000.
Humans are sometimes bound to a large kite to fly, as many hang gliders are true kites. The first known example is Yuan Huangtou in 550AD.
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.
According to Samguk Sagi, in 637, Kim Yu-sin, a Korean general of Silla rallied his troops to defeat rebels by lofting a kite with a straw man which looked like a burning ball flying to the sky.[26]
Russian chronicles mention prince Oleg of Novgorod use kites during the siege of Constantinople in 906 A.D.: "and he crafted horses and men of paper, armed and gilded, and lifted them into the air over the city; the Greeks saw them and feared".
Kites were also used by Admiral Yi of the Joseon Dynasty (1392-1910) 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.[27] The war eventually resulted in a Korean victory; the kites played a minor role in the war's conclusion.
One of Cody's "manlifter" kites in 1908
In more modern times the British Army used kites to haul human lookouts high into the air for observation purposes, using the kites developed by Samuel Franklin Cody. Barrage kites were used to protect shipping during the last Second World War.[28][29] Kites were also used for anti-aircraft target practice.[30] Kites and kytoons were used for lofting communications antenna.[31] Submarines lofted observers in rotary kites.[32] The Rogallo parawing kite[33] and the Jalbert parafoil kite were used for governable parachutes (free-flying kites) to deliver troops and supplies.[34]
Kites have been used for scientific purposes, such as Benjamin Franklin's famous experiment proving that lightning is electricity. Kites were the precursors to the traditional 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 a historical role in lifting scientific instruments to measure atmospheric conditions for weather forecasting.
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.
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, kite boating 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.[35] 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.[36] Kites are available as an auxiliary sail or emergency spinnaker for sailing boats. Self-launching Parafoil kites are attached to the mast.[citation needed]
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".[37]
Conceptual research and development projects by over a hundred entities are investigating the use of kites in harnessing high altitude wind currents to generate electricity.[38]
Delft University of Technology is developing a kite power technology demonstrator system based on a 25 m² kite generating 20 kW mechanical traction power. The system is tested regularly since January 2010.[39]
At the Katholieke Universiteit Leuven a research group is investigating the use of kites for power generation. Rather than a flexible kite, they use a rigid structure like an aircraft wing, because of its greater aerodynamic efficiency, easier control, and more predictable dynamics. A small prototype is being built.[40]
Launch of ram-air inflated
Peter Lynn single-line kite, shaped like an octopus and 90 feet (27 m) long.
Kite festivals are a popular form of entertainment throughout the world. They include large local events, traditional festivals which have been held for 300 hundreds of years and major international festivals which bring in kite flyers from Britain to display their unique art kites and demonstrate the latest technical kites.
Making a traditional
Wau jala budi kite in
Malaysia. The bamboo frame is covered with plain paper and then decorated with multiple layers of shaped paper and foil.
Kite flying is popular in many Asian countries, where it often takes the form of 'kite fighting', in which participants try to snag each other's kites or cut other kites down.[41] Fighter kites are usually small, flat, flattened diamond-shaped kites made of paper and bamboo. Tails are not used on fighter kites so that agility and maneuverability are not compromised.
In Afghanistan, kite flying is a popular game, and is known in Dari as Gudiparan Bazi. Some kite fighters pass their strings through a mixture of ground glass powder and glue. The resulting strings are very abrasive and can sever the competitor's strings more easily. The abrasive strings can also injure people. During the Taliban rule in Afghanistan, kite flying was banned, among various other recreations.
In Pakistan, kite flying is often known as Gudi-Bazi or Patang-bazi. Although kite flying is a popular ritual for the celebration of spring festival known as Jashn-e-Baharaan (lit. Spring Festival) or Basant, kites are flown throughout the year. Kite fighting is a very popular all around Pakistan, but centered in urban centers across the country especially Lahore. The kite fights are at their maximum during the spring celebrations and the fighters enjoy competing with rivals in which one have to cut-loose the string of the kite of other, this is popularly called as "Paecha". During the spring festival, kite flying competitions are held across the country and the skies are colored with kites. As people cut-loose an opponents kites, shouts of 'wo kata' ring through the air. Reclaiming the kites, after they have been cut-loose by running after them, is a popular ritual especially among the youth (similar to scenes depicted in the Kite Runner which is based in neighboring Afghanistan). Kites and strings are a big business in the country and many types of strings are used: glass-coated strings, metal strings and tandi. However, kite flying was recently banned in Punjab due to recent motorcyclist deaths caused by glass-coated or metal kite-strings. Kup, Patang, Guda, and Nakhlaoo are some of the kites used. They vary in balance, weight and speed through the air.
In Vietnam, kites are flown without tails. Instead small flutes are attached allowing the wind to "hum" a musical tune. There are other forms of sound-making kites. In Bali, large bows are attached to the front of the kites to make a deep throbbing vibration, and in Malaysia row of gourds with sound-slots are used to create a whistle as the kite flies.[42]
Kites are popular during the Indian festival of Makar Sankranti. This spring festival is celebrated generally during mid of January, in accordance with the Indian calender, with millions of people flying kites all over northern India. The states of Bihar, Jharkhand, Gujarat, West Bengal, Rajasthan, Punjab etc. are notable for their kite fighting festivals. Kite flying in Hyderabad starts a month before the official kite flying festival (Sankranthi). The thread used to fly kites is known as 'Manjaa'. Highly maneuverable single-string paper and bamboo kites are flown from the rooftops while using line friction in an attempt to cut each other's kite lines, either by letting the line loose at high speed or by pulling the line in a fast and repeated manner. Kite flying/fighting is an important part of other celebrations, including Republic Day, Independence Day, Raksha Bandhan, and Janmashtami. An international kite festival is held every year before Uttarayan for three days in Vadodara, Surat and Ahmedabad. People start flying kites early in the morning and continue until the evening. The kite is known as 'Patang' in India. People fly kites in Indian Punjab on occasion of Lohri (Punjabi name for Makar Sankranti) and Basant Punchami.
Weifang, Shandong, China is the kite capital of the world. China is the oldest place, probably with India where kites have been flown since antiquities. It is home to the largest kite museum in the world, the thousands of kites here have a display area of 8100 m2. Weifang hosts an annual international kite festival on the large salt flats south of the city. There are several kite museums in Japan, UK, Malaysia, Indonesia, Taiwan, Thailand and the USA.
In the olden days, Malays in Singapore, kites is used for fishing.[43]
In Greece and Cyprus, flying kites is a tradition for Clean Monday, the first day of Lent. In the British Overseas Territory of Bermuda, traditional Bermuda kites are made and flown at Easter, to symbolise Christ's ascent. Bermuda kites hold the world records for altitude and duration. In Fuerteventura a kite festival is usually held on the weekend nearest to 8 November lasting for 3 days.
Polynesian traditional kites are sometimes used at ceremonies and variants of traditional kites for amusement. Older pieces are kept in museums.
In Chile, it is very popular, especially during Independence Day festivities (September 18).
In Colombia kites can be seen flown in parks and recreation areas during August which is known to be windy. It is during this month that most people, especially the young ones would fly kites.
In Guyana, kites are flown at Easter and is an activity participated in by all ethnic and religious groups. Kites are generally not flown at any other time of year. Kites start appearing in the sky in the weeks leading up to Easter and school children are taken to parks for the activity. It all culminates in a massive airborne celebration on Easter Monday especially in Georgetown, the capital, and other coastal areas. The history of the practice is not entirely clear but given that Easter is a Christian festival, it is said that the flying kite is symbolic of the Risen Lord. Moore[44] describes the phenomenon in the 19th century as follows:
A very popular Creole pastime was the flying of kites. Easter Monday, a public holiday, was the great kite-flying day on the sea wall in Georgetown and on open lands in villages. Young and old alike, male and female, appeared to be seized by kite-flying mania. Easter 1885 serves as a good example. “The appearance of the sky all over Georgetown, but especially towards the Sea Wall, was very striking, the air being thick with kites of all shapes and sizes, covered with gaily coloured paper, all riding bravely on the strong wind"
(His quotation is from a letter to The Creole newspaper of December 29, 1858). The exact origins of the practice of kite flying (exclusively) at Easter are unclear. Brereton and Yelvington[45] speculate that kite flying was introduced by Chinese indentured immigrants to the then colony of British Guyana in the mid 19th century. The author of an article in the Guyana Chronicle newspaper of May 6, 2007 is more certain:
Kite flying originated as a Chinese tradition to mark the beginning of spring. However, because the plantation owners were suspicious of the plantation workers, the Chinese claimed that it represented the resurrection of Jesus Christ. It was a clever argument, as at that time, Christians celebrated Easter to the glory of the risen Christ.
[46]
There are safety issues involved in kite-flying, more so with power kites. Kite lines can strike and tangle on electrical power lines, causing power blackouts and running the risk of electrocuting the kite flier. Wet kite lines or wire can act as a conductor for static electricity and lightning when the weather is stormy. Kites with large surface areas or powerful lift can lift kite fliers off the ground or drag them into stationary objects. In urban areas there is usually a ceiling on how high a kite can be flown, to prevent the kite and line infringing on the airspace of helicopters and light aircraft.
Until Bristol Kite Festival 2011 ended, the world record for the biggest-ever kite flown for at least 20 minutes was a kite with lifting area of 10,971 square feet.[47]
- ^ Beginner's Guide to Aeronautics, NASA
- ^ Flying High, Down Under When the kite line broke, the kites still received tension from the very long kite line.
- ^ Parakites by Gilbert Totten Woglom, 1896.
- ^ Science in the Field: Ben Balsley, CIRES Scientist in the Field Gathering atmospheric dynamics data using kites. Kites are anchored to boats on Amazon River employed to sample levels of certain gases in the air.
- ^ The Bachstelze Article describes the Fa-330 Rotary Wing Kite towed by its mooring to the submarine. The kite was a man-lifter modeled after the autogyro principle.
- ^ Kite Fashions: Above, Below, Sideways. Expert kiter sometimes ties a flying kite to a tree to have the kite fly for days on end.
- ^ Underwater kiting
- ^ Hydro kite angling device Jason C. Hubbart.
- ^ Underwater kite F. G. Morrill.
- ^ Domina Jalbert
- ^ Deep In the Heart of Texas by Dave Broyles Boat kiting
- ^ Focke-Achgelis Fa 330A-1 Bachsteltze (Water Wagtail) Kite is preserved in the Smithsonian National Air and Space Museum
- ^ An alternative theory from kite authors Clive Hart and Tal Streeter holds that leaf kites existed far before that time in what is now Indonesia, based on their interpretation of cave paintings on Muna Island off Sulawesi
- ^ Drachen Foundation Journal Fall 2002, page 18. Two lines of evidence: analysis of leaf kiting and some cave drawings
- ^ a b Needham, Volume 4, Part 1, 127.
- ^ "Amazing Musical Kites", CAMBODIA PHILATELY
- ^ Kite Flying for Fun and Science, 1907, NY Times
- ^ "Khmer Kites", Sim Sarak and Cheang Yarin, Ministry of Culture and Fine Arts, Cambodia 2002
- ^ PIYUSH KUMAR TRIPATHI (7 January 2012). "Kite fights to turn skies colourful on Makar Sankranti - Professional flyers to showcase flying skills; food lovers can relish delicacies at snack huts". http://www.telegraphindia.com/1120107/jsp/bihar/story_14974741.jsp#.T7owAkXrqMo.
- ^ Tarlton, John. "Ancient Maori Kites". Ancient Maori Kites. http://www.art-newzealand.com/Issues1to40/kites.htm. Retrieved 19 October 2011.
- ^ Chadwick, Nora (1907-1965 (Vols. 37-95)). The Journal of the Royal Anthropological Institute of Great Britain and Ireland. The Kite: A Study in Polynesian Tradition: Royal Anthropological Institute of Great Britain and Ireland. pp. 455. JSTOR 2843932.
- ^ a b Anon. "Kite History: A Simple History of Kiting". G-Kites. http://www.gombergkites.com/nkm/hist1.html. Retrieved 20 June 2010.
- ^ a b http://www.mos.org/sln/toe/kite.html
- ^ http://www.amazon.com/Bolt-Fate-Benjamin-Franklin-Electric/dp/1891620703
- ^ "History of Kites". http://kites.com/history-of-kites.html. Retrieved 18 April 2012.
- ^ "연 鳶 (Yeon)" (in Korean). Nate / Encyclopedia of Korean Culture. http://100.nate.com/dicsearch/pentry.html?s=K&i=251011&v=44. Retrieved July 30, 2009. "우리 나라에서는 ≪삼국사기≫ 열전(列傳) 김유신조(金庾信條)에, 진덕왕 즉위 1년에 대신 비담(毗曇)과 염종(廉宗)의 반란이 일어났을 때 월성(月城)에 큰 별이 떨어지므로 왕이 크게 두려워하자 김유신이 허수아비를 만들어 연에 달아 띄우니 불덩이가 하늘에 올라가는 듯하였다는 기사가 처음으로 나온다. 이로 볼 때 이 시기에는 이미 연이 일반화되어 있었으며, 또한 놀이로서의 도구뿐만 아니라 전쟁의 도구로도 사용되었음을 알 수 있다."
- ^ "신호연신호 개요 (Summary of sending a signal with a kite)" (in Korean). Korea Culture & Contents Agency. http://chosunpass.culturecontent.com/sub.asp?mode=3&t1=9&m1=4&c1=pc17. Retrieved July 30, 2009. "특히, 조선시대 임진왜란 때에는 충무공 이순신 장군이 충무공전술비연을 제작하여 섬과 섬, 섬과 육지 등을 서로 연락하는 통신수단 및 작전을 지시하는 전술신호와 암호 수단으로 사용한 예"
- ^ Kites On The Winds of War By M. Robinson
- ^ Barrage Kite
- ^ http://www.rexresearch.com/garbrkit/garbrkit.htm
- ^ World Kite Museum
- ^ Focke Achgelis Fa 330
- ^ The Parachute Manual: A Technical Treatise on Aerodynamic Decelerators By Dan Poynter
- ^ Army Aims for More Precise Ways to Drop Troops, Cargo
- ^ Andrew Revkin (January 23, 2008). "It's a freighter, it's a sailboat - no it's both". The New York Times. http://dotearth.blogs.nytimes.com/2008/01/23/look-its-a-freighter-its-a-sailboat-its-both/. Retrieved May 7, 2010.
- ^ Skysail ship pulling system
- ^ BBC NEWS, Kite to pull ship across Atlantic
- ^ http://energykitesystems.net/index.html
- ^ http://www.kitepower.eu
- ^ http://www.kuleuven.be/optec/research/projects/kitepower
- ^ Kite.(2007) Encyclopædia Britannica Online
- ^ Pogadaev, Victor. Svetly Mesyatz-Zmei Kruzhitsa (My Lord Moon Kite) - “Vostochnaya Kollektsia” (Oriental Collection). M.: Russian State Library. N 4 (38), 2009, 129-134. ISSN 1681—7559
- ^ Malay magic: an introduction to the folklore and popular religion of the ... By Walter William Skeat
- ^ Brian L. Moore "Cultural power, resistance, and pluralism: Colonial Guyana 1838-1900" McGill-Queen's Press - MQUP, 1995, ISBN 0-7735-1354-X, 9780773513549
- ^ Bridget Brereton and Kevin A. Yelvington "The colonial Caribbean in transition" University Press of Florida, 1999, ISBN 0-8130-1696-7, ISBN 978-0-8130-1696-2
- ^ http://www.guyanachronicle.com/ARCHIVES/archive%2006-05-07.html
- ^ "World's biggest kite - larger than a football pitch - fails to soar at Bristol festival". September 4, 2011. http://www.dailymail.co.uk/news/article-2033522/Worlds-biggest-kite--larger-football-pitch--fails-soar-Bristol-festival.html?ITO=1490.
.png)
