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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 a Wikimedia movement affinity group for contributors with shared goals. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within Wikimedia project, sister 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 outside organization ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uvalde, Texas
Uvalde is a city and the county seat of Uvalde County, Texas, United States. The population was 15,217 at the 2020 census. 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). 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 Hispanic community is or general knowledge of its pronunciation. History Uvalde was founded by Reading Wood Black in 1853 as the town of Encina. In 1856, when the county was organize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teflon
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally discovered 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. Where used as a lubricant, P ... [...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. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of the structure. Crashworthiness may be assessed either prospectively, using computer models (e.g., 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 as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technischer Überwachungsverein
TÜVs (; short for german: Technischer Überwachungsverein, en, Technical Inspection Association) are internationally active, independent service companies from Germany and Austria that test, inspect and certify technical systems, facilities and objects of all kinds in order to minimize hazards and prevent damages. The TÜV companies are organized into three large holding companies, TÜV Nord, TÜV Rheinland and TÜV SÜD (with TÜV Hessen), along with the smaller independent companies TÜV Thüringen, TÜV Saarland and TÜV Austria. History With the increasing number and efficiency of steam engines during the Industrial Revolution, there had been more and more accidents caused by exploding (or more precisely, bursting) boilers. After the explosion of the boiler at the Mannheim Aktienbrauerei in January 1865, the idea was pursued there to subject boilers to regular inspections on a voluntary basis, as was already the case in Great Britain. Twenty boiler owners in Baden joined in ... [...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 ... [...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 plastic (GFRP ... [...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 body armor fabric and ballistic composites, in marine cordage, marine hull reinforcement, and as an asbestos substitute. 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 fibers. Aramids have a very high melting point (>500 °C). Common aramid brand names include Kevlar, Nomex, and Twaron. Terminology and chemical structure ''Aramid'' is a shortened form of aromatic polyamide. The term 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 the International Standards Organisation in 1977. Aromatic in the name refers to the presence of aromatic r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washout (aviation)
Washout is a characteristic of aircraft wing design which deliberately reduces the lift distribution across the span of an aircraft’s wing. The wing is designed so that the 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 speed the wing root stalls before the wing tips, providing the aircraft with continued aileron control and some resistance to 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 with a slight twist, reducing the 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 structural washout, to distinguish it from aerodynamic washout. Wingtip stall is unlikely to occur symmetrically, especially if the aircraft is maneuvering. As ... [...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. T ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Stuttgart
The University of Stuttgart (german: Universität Stuttgart) is a leading 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 highly ranked 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. The university is especially known for its reputation in the fields of advanced automotive engineering, efficient industrial and automated manufacturing, process engineering, aerospace engineering and activity-based costing. History From 1770 to 1794, the Karlsschule was the first university in Stuttgart. Located in Stuttgart-Hohenheim, it has since 1818 been the University of Hohenheim and is not related to the University of Stuttgart, except for some joint activities. What is now the University of Stuttgart was found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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