|
Kite Types
Kites are tethered flying objects which fly by using aerodynamic lift, requiring wind (or towing) for generation of airflow over the lifting surfaces. Various types of kites exist, depending on features such as material, shape, use, or operating skills required. Kites may fly in air, water, or other fluids such as gas and other liquid gaining lift through deflection of the supporting medium. Variations in design of tethering systems and lifting surfaces are regularly introduced, with lifting surfaces varying in stiffness from limp sheet material to fully solid material. Manufacture Kites may be built by the flier or by a dedicated kite manufacturer, which may be a member of the Kite Trade Association International (KTAI), which also includes kite retailers. Materials Kites have been made from the following materials: *Plastic – for example, a Styrofoam-only kite *Organic materials – such as plant leaves and grass *Paper *Textiles such as rip-stop nylon, nylon, or Dac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taliban
The Taliban (; ps, طالبان, ṭālibān, lit=students or 'seekers'), which also refers to itself by its state name, the Islamic Emirate of Afghanistan, is a Deobandi Islamic fundamentalist, militant Islamist, jihadist, and Pashtun nationalist political movement in Afghanistan. It ruled approximately three-quarters of the country from 1996 to 2001, before being overthrown following the United States invasion. It recaptured Kabul on 15 August 2021 after nearly 20 years of insurgency, and currently controls all of the country, although its government has not yet been recognized by any country. The Taliban government has been criticized for restricting human rights in Afghanistan, including the right of women and girls to work and to have an education. The Taliban emerged in September 1994 as one of the prominent factions in the Afghan Civil War and largely consisted of students () from the Pashtun areas of eastern and southern Afghanistan who had been educate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kytoon
A kytoon or kite balloon is a tethered aircraft which obtains some of its lift dynamically as a heavier-than-air kite and the rest aerostatically as a lighter-than-air balloon. The word is a portmanteau of kite and balloon. The primary advantage of a kytoon is that it remains in a reasonably stable position above the tether point, irrespective of the strength of wind, whereas ordinary balloons and kites are less stable. The kytoon has been used for many purposes both civil and military. History In 1919, a handbook was published giving extensive details to support the kite balloon crafts being used in the military. Described is the first kite balloon made in 1893 by Captains Parseval and Sigsfeld at the Berlin works of the Prussian Balloon Battalion; theirs was the "predecessor of the ''Drachen'' balloon." "This was the first real kite balloon flying like a kite with a fairly constant angle and direction relative to the wind and remained practically unchanged until the beginning o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autorotation (helicopter)
Autorotation is a state of flight in which the main rotor system of a helicopter or other rotary-wing aircraft turns by the action of air moving up through the rotor, as with an autogyro, rather than engine power driving the rotor. Bensen, Igor.How they fly – Bensen explains all" ''Gyrocopters UK''. Accessed: 10 April 2014. Quote: "air.. (is) deflected downward"Charnov, Bruce HCierva, Pitcairn and the Legacy of Rotary-Wing Flight ''Hofstra University''. Accessed: 22 November 2011. The term ''autorotation'' dates to a period of early helicopter development between 1915 and 1920, and refers to the rotors turning without the engine."Autorotation", ''Dictionary.com Unabridged (v 1.1)''. Random House, Inc. 17 April 2007 It is analogous to the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autogyro
An autogyro (from Greek and , "self-turning"), also known as a ''gyroplane'', is a type of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. Forward thrust is provided independently, by an engine-driven propeller. While similar to a helicopter rotor in appearance, the autogyro's rotor must have air flowing across the rotor disc to generate rotation, and the air flows upwards through the rotor disc rather than down. The autogyro was invented by Spanish engineer Juan de la Cierva in an attempt to create an aircraft that could fly safely at low speeds. He first flew one on 9 January 1923, at Cuatro Vientos Airfield in Madrid. The aircraft resembled the fixed-wing aircraft of the day, with a front-mounted engine and propeller. Cierva's autogyro is considered the predecessor of the modern helicopter. The success of the autogyro garnered the interest of industrialists and under license from Cierva in the 1920s and 1930s, the Pitcairn & Kellett compani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francisco Goya
Francisco José de Goya y Lucientes (; ; 30 March 174616 April 1828) was a Spanish romantic painter and printmaker. He is considered the most important Spanish artist of the late 18th and early 19th centuries. His paintings, drawings, and engravings reflected contemporary historical upheavals and influenced important 19th- and 20th-century painters. Goya is often referred to as the last of the Old Masters and the first of the moderns. Goya was born to a middle-class family in 1746, in Fuendetodos in Aragon. He studied painting from age 14 under José Luzán y Martinez and moved to Madrid to study with Anton Raphael Mengs. He married Josefa Bayeu in 1773. Their life was characterised by a series of pregnancies and miscarriages, and only one child, a son, survived into adulthood. Goya became a court painter to the Spanish Crown in 1786 and this early portion of his career is marked by portraits of the Spanish aristocracy and royalty, and Rococo-style tapestry cartoons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabolic Arch
A parabolic arch is an arch in the shape of a parabola.Article about parabolic arch by The Free DictionaryParabolic arch , Article about parabolic arch by The Free Dictionary accessdate: March 2, 2017 In structures, their curve represents an efficient method of load, and so can be found in bridges and in architecture in a variety of forms. Description The mathematics While a parabolic arch may resemble a catenary arch, a parabola is a quadratic function while a catenary is the hyperbolic cosine, , a sum of two exponential functions. One parabola is , and hyperbolic cosine is . The curves are unrelated. The line of thrust Unlike a catenary arch, the parabolic arch employs the principle that when weight is uniformly applied above, the internal compression (see line of thrust) resulting from that weight will follow a parabolic curve. Of all arch types, the parabolic arch produces the most thrust at the base. Also, it can span the widest area. It is commonly used in bridge design, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedean Screw
The Archimedes screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest hydraulic machines. Using Archimedes screws as water pumps (Archimedes screw pump (ASP) or screw pump) dates back many centuries. As a machine used for transferring water from a low-lying body of water into irrigation ditches, water is pumped by turning a screw-shaped surface inside a pipe. In the modern world, Archimedes screw pumps are widely used in wastewater treatment plants and for dewatering low-lying regions. Archimedes Screws Turbines (ASTs) are a new form of small hydroelectric powerplant that can be applied even in low head sites. Archimedes screw generators operate in a wide range of flows (0.01 m^3/s to 14.5 m^3/s) and heads (0.1 m to 10 m), including low heads and moderate flow rates that is not ideal for traditional turbines and not occupied by high performance technologies. The Archimedes screw is a reversible hydraulic machine, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peel Glider Boat
The Peel Z-1 Glider Boat, also called the Peel Flying Boat, is an American biplane, two-seats-in-tandem, flying boat glider that was designed and produced by the Peel Glider Boat Company, starting in about 1930. Design and development The Glider Boat was intended as a strictly recreational aircraft, to be towed from the water surface by a powered boat. The company intended to produce a very inexpensive aircraft to cash in on the sudden popularity of aviation following Charles Lindbergh’s 1927 solo flight across the Atlantic Ocean. The aircraft is of mixed construction. The span wing has a wooden spar, steel ribs and is covered in doped aircraft fabric covering. The two wings have a large total area of and combined with the light gross weight of give a very light wing loading of just 2.2 lb/sq ft (11 kg/m2). The lower wing tips feature wingtip floats. The hull is made from duralumin and features a stepped shape, similar to most powered flying boats. The aircraft has conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangle Control Frame
Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised foot-launched heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame covered with synthetic sailcloth to form a wing. Typically the pilot is in a harness suspended from the airframe, and controls the aircraft by shifting body weight in opposition to a control frame. Early hang gliders had a low lift-to-drag ratio, so pilots were restricted to gliding down small hills. By the 1980s this ratio significantly improved, and since then pilots have been able to soar for hours, gain thousands of feet of altitude in thermal updrafts, perform aerobatics, and glide cross-country for hundreds of kilometers. The Federation Aeronautique Internationale and national airspace governing organisations control some regulatory aspects of hang gliding. Obtaining the safety benefits of being instructed is highly recommended and indeed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paresev
The NASA Paresev ("Paraglider Research Vehicle") was an experimental NASA glider aircraft based upon the kite-parachute studies by NASA engineer Francis Rogallo. Between 1961 and 1965 the ability of the Rogallo wing (also called "Parawing") to descend a payload such as the Project Gemini, Gemini space capsule safely from high altitude to ground was studied.Aviation News article The Paresev was a test vehicle used to learn how to control this parachute-wing for a safe landing at a normal airfield. Publicity on the Paresev and the Ryan XV-8, Ryan XV-8 "Flying Jeep" aircraft inspired hobbyists to adapt Rogallo's flexible wing airfoil onto elementary History of hang gliding, hang gliders leading to the most successful hang glider configuration in history. Development [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
