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Rolladen-Schneider LS6
The Rolladen-Schneider LS6 is a 15 metre and 18 metre single-seat flapped glider manufactured by Rolladen-Schneider Flugzeugbau GmbH between 1984 and 2003. Development The prototype of the LS6, successor to the LS3 in the FAI 15 metre Class, made its first flight in 1983. Having entered production one year later, the LS6 had an uncommonly long production run ended by Rolladen-Schneider's entry into receivership in 2003. A total of 375 of all versions were built. A watershed design, the LS6 introduced carbon reinforced plastic as a structural material in LS-gliders, thin profiles for wings and empennage, wing extensions and other features that have been retained in all subsequent types developed by the company. The Akaflieg Darmstadt D41, the LS9 and the Akaflieg Köln LS11 all have wings built in the LS6 moulds. Bettering the record of the LS4 in the Standard Class, the LS6 dominated the 15 metre Class over nearly a decade, winning the first two places at the 1985 Wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WikiProject Aircraft
A WikiProject, or Wikiproject, is an affinity group for contributors with shared goals within the Wikimedia movement. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within Wikimedia project, sibling projects such as Wiktionary, Wikiquote, Wikidata, and Wikisource. They also exist in different languages, and translation of articles is a form of their collaboration. During the COVID-19 pandemic, CBS News noted the role of Wikipedia's WikiProject Medicine in maintaining the accuracy of articles related to the disease. Another WikiProject that has drawn attention is WikiProject Women Scientists, which was profiled by ''Smithsonian Magazine, Smithsonian'' for its efforts to improve coverage of women scientists which the profile noted had "helped increase the number of female scientists on Wikipedia from around 1,600 to over 5,000". On Wikipedia Some Wikipedia WikiProjects are substantial enough to engage in cooperative activities with outsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uvalde, Texas
Uvalde ( ) is a city in and the county seat of Uvalde County, Texas, United States. The population was 15,217 at the 2020 census, down from 15,751 in 2010. It is the principal city in the Uvalde, Texas Micropolitan Statistical Area. Uvalde is located in the Texas Hill Country, west of downtown San Antonio and east of the Mexico–United States border. Name Uvalde was founded in 1853 as the town of ''Encina'', but was renamed in 1856 as ''Uvalde''. Its name is a misspelling of the Spanish governor Juan de Ugalde (Cádiz, Andalusia, 1729–1816). Ugalde is a name of Basque origin, meaning water-side or river. Pronunciations of the name of the town vary. One common pronunciation is the fully Anglicized version ( ). A fully Spanish version is also in common use, which is often approximated by English speakers as . There are also pronunciations that combine the English and Spanish versions. The chosen pronunciation often shows how strong a person's connection with the His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teflon
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally invented the compound in 1938. Polytetrafluoroethylene is a fluorocarbon solid, as it is a high- molecular-weight polymer consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances wet PTFE, as fluorocarbons exhibit only small London dispersion forces due to the low electric polarizability of fluorine. PTFE has one of the lowest coefficients of friction of any solid. Polytetrafluoroethylene is used as a non-stick coating for pans and other cookware. It is non-reactive, partly because of the strength of carbon–fluorine bonds, so it is often used in containers and pipework for reactive and corrosive chemicals. When used as a lubricant, PTFE reduces fric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Different criteria are used to figure out how safe a structure is in a crash, depending on the type of impact and the vehicle involved. Crashworthiness may be assessed either prospectively, using computer models (e.g., RADIOSS, LS-DYNA, PAM-CRASH, MSC Dytran, MADYMO) or experiments, or retrospectively, by analyzing crash outcomes. Several criteria are used to assess crashworthiness prospectively, including the deformation patterns of the vehicle structure, the acceleration experienced by the vehicle during an impact, and the probability of injury predicted by human body models. Injury probability is defined using criteria, which are mechanical parameters (e.g., force, acceleration, or deformation) that correlate with injury risk. A common injury criterion is the head impact criterion (HIC). Crashworthiness is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crash Test
A crash test is a form of destructive testing usually performed in order to ensure safe design standards in crashworthiness and crash compatibility for various modes of transportation (see automobile safety) or related systems and components. Types * Frontal-impact tests: which is what most people initially think of when asked about a crash test. Vehicles usually impact a solid concrete wall at a specified speed, but these can also be vehicle impacting vehicle tests. SUVs have been singled out in these tests for a while, due to the high ride-height that they often have. * Moderate Overlap tests: in which only part of the front of the car impacts with a barrier (vehicle). These are important, as impact forces (approximately) remain the same as with a frontal impact test, but a smaller fraction of the car is required to absorb all of the force. These tests are often realized by cars turning into oncoming traffic. This type of testing is done by the U.S.A. Insurance Insti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass-reinforced Plastic
Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinyl ester resin—or a thermoplastic. Cheaper and more flexible than carbon fiber, it is stronger than many metals by weight, non- magnetic, non- conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, orthopedic casts, surfboards, and external door skins. Other common names for fiberglass are glass-reinforced plastic (GRP), glass-fiber reinforced plas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aramid
Aramid fibers, short for aromatic polyamide, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated bulletproof vest, body armor cloth, fabric and ballistic composites, in marine cordage, marine hull reinforcement, as an asbestos substitute, and in various lightweight consumer items ranging from phone cases to tennis rackets. The chain molecules in the fibers are highly oriented along the fiber axis. As a result, a higher proportion of the chemical bond contributes more to fiber strength than in many other synthetic fibres in the world. Aramids have a very high melting point (>). Common aramid brand names include Kevlar, Nomex, and Twaron. Terminology and chemical structure The term ''aramid'' is shortened from ''aromatic polyamide''. It was introduced in 1972, accepted in 1974 by the Federal Trade Commission of the USA as the name of a generic category of fiber distinct from nylon, and adopted by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washout (aviation)
Washout is a characteristic of aircraft wing design which deliberately changes the Lift (force), lift distribution across the Wingspan, span of an aircraft’s wing. The wing is designed so that the angle of incidence (aerodynamics), angle of incidence is greater at the wing roots and decreases across the span, becoming lowest at the wing tip. This is usually to ensure that at Stall (flight), stall speed the wing root stalls before the wing tips, providing the aircraft with continued aileron control and some resistance to Spin (flight), spinning. Washout may also be used to modify the spanwise lift distribution to reduce lift-induced drag. Design considerations Washout is commonly achieved by designing the Wing#Artificial Wings, wing with a slight Wing twist, twist, reducing the angle of incidence (aerodynamics), angle of incidence from root to tip, and therefore causing a lower angle of attack at the tips than at the roots. This feature is sometimes referred to as geometrica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thickness-to-chord Ratio
In aeronautics, the thickness-to-chord ratio, sometimes simply chord ratio or thickness ratio, compares the maximum vertical thickness of a wing to its chord. It is a key measure of the performance of a wing planform when it is operating at transonic speeds. At speeds approaching the speed of sound, the effects of Bernoulli's principle over curves on the wing and fuselage can accelerate the local flow to supersonic speeds. This creates a shock wave that produces a powerful form of drag known as wave drag, and gives rise to the concept of the sound barrier. The speed at which these shocks first form, critical mach, is a function of the amount of curvature. In order to reduce wave drag, wings should have the minimum curvature possible while still generating the required amount of lift. So, the main reason for decreasing the blade section thickness to chord ratio is to delay the compressibility effect related to higher Mach numbers, delaying the onset of a shock wave formation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Xaver Wortmann
Franz Xaver Wortmann (September 24, 1921 - January 16, 1985) was a German aerodynamicist. Early life After World War II, Wortmann spent time as a pilot and observer with the German Air Force. He then studied physics in Münster and Stuttgart. After graduating in the field of fluid theory he completed his doctorate as an engineer in 1955. His habilitation followed in 1963. Together with Richard Eppler and Dieter Althaus, Wortmann carried out ground-breaking work in the late 1950s and the 1960s in the field of development of laminar flow airfoil profiles using the inverse design method. His wing profile designs are known by the FX (for Franz Xaver) in their code. These wing profiles were used in many of the first and second generation of fibre-reinforced plastic gliders. By the early 1970s, many successful designs of glider had a wing based on a Wortmann profile. In 1974 Wortmann took over the leadership of the Institute of Aerodynamics and Gas Dynamics at the University of Stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Stuttgart
The University of Stuttgart () is a research university located in Stuttgart, Germany. It was founded in 1829 and is organized into 10 faculties. It is one of the oldest technical universities in Germany with programs in civil, mechanical, industrial and electrical engineering, among others. It is a member of TU9, an incorporated society of the largest and most notable German institutes of technology. History From 1770 to 1794, the Karlsschule was the first university in Stuttgart. The University of Hohenheim in Stuttgart-Hohenheim, founded in 1818 and Stuttgart's oldest still existing university, is not related to the University of Stuttgart, except for some joint activities. What is now the University of Stuttgart was founded in 1829, and celebrated its 175th anniversary in 2004. Because of the increasing importance of the technical sciences and instruction in these fields, from 1876 the university was known as the Technische Hochschule Stuttgart (Stuttgart Institute of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
