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Standard Wind Tunnel Models
Standard wind tunnel models, also known as reference models, calibration models (french: maquettes d'étalonnage) or test check-standards are objects of relatively simple and precisely defined shapes, having known aerodynamic characteristics, that are tested in wind tunnels. Standard models are used in order to verify, by comparison of wind tunnel test results with previously published results, the complete measurement chain in a wind tunnel, including wind tunnel structure, quality of the airstream, model positioning, transducers and force balances, data acquisition system and data reduction software.Reed T.D., Pope T.C., Coksey T.M."Calibration of Transonic and Supersonic Wind Tunnels" NASA CR 2920, NASA, 1977Pope A."Wind Tunnel Calibration Techniques" AGARDograph 54, AGARD, 1961 More specifically, standard wind tunnel models are used for: *confirmation of the reliability of the data from a new wind tunnel by comparison with results from other wind tunnel facilities; *providin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NACA 0012 Airfoil
The NACA airfoils are airfoil shapes for aircraft wings developed by the National Advisory Committee for Aeronautics (NACA). The shape of the NACA airfoils is described using a series of digits following the word "NACA". The parameters in the numerical code can be entered into equations to precisely generate the cross-section of the airfoil and calculate its properties. Origins NACA initially developed the numbered airfoil system which was further refined by the United States Air Force at Langley Research Center. According to the NASA website: Four-digit series The NACA four-digit wing sections define the profile by: # First digit describing maximum camber as percentage of the chord. # Second digit describing the distance of maximum camber from the airfoil leading edge in tenths of the chord. # Last two digits describing maximum thickness of the airfoil as percent of the chord. For example, the NACA 2412 airfoil has a maximum camber of 2% located 40% (0.4 chords) from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sting (fixture)
In experimental fluid mechanics, a sting is a test fixture on which models are mounted for testing, e.g. in a wind tunnel. A sting is usually a long shaft attaching to the downstream end of the model so that it does not much disturb the flow over the model. The rear end of a sting usually has a conical fairing blending into the (wind tunnel) model support structure. For minimum aerodynamic interference a sting should be as long as possible and have as small a diameter as possible, within the structural safety limits. Critical length of a sting (beyond which its influence on the flow around the model is small) is mostly dependent on Reynolds number. If the flow at the rear end of a model (model base) is laminar, the critical sting length can be as much as 12-15 base diameters.A.Pope, "W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chord (aeronautics)
In aeronautics, the chord is an imaginary straight line joining the leading edge and trailing edge of an aerofoil. The chord length is the distance between the trailing edge and the point where the chord intersects the leading edge.L. J. Clancy (1975), ''Aerodynamics'', Section 5.2, Pitman Publishing Limited, London. The point on the leading edge used to define the chord may be the surface point of minimum radius. p.18 For a turbine aerofoil the chord may be defined by the line between points where the front and rear of a 2-dimensional blade section would touch a flat surface when laid convex-side up. The wing, horizontal stabilizer, vertical stabilizer and propeller/rotor blades of an aircraft are all based on aerofoil sections, and the term ''chord'' or ''chord length'' is also used to describe their width. The chord of a wing, stabilizer and propeller is determined by measuring the distance between leading and trailing edges in the direction of the airflow. (If a wing has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIRA Ltd
HORIBA MIRA Ltd. (formerly the Motor Industry Research Association) is an automotive engineering and development consultancy company headquartered near Nuneaton in Warwickshire, United Kingdom. It provides product engineering, research, testing, information and certification services to the automotive sector. Its headquarters are in the MIRA Technology Park Enterprise Zone. On 14 July 2015 MIRA announced that it was being bought by the Japanese-owned testing equipment group Horiba. History Origins MIRA was formed in 1946 and was mostly government-funded. It is based just off the A5 near the junction with the A444 in the parish of Higham on the Hill (also near Fenny Drayton), Leicestershire, where over six hundred staff work, with another establishment in Basildon in Essex. The company dates back to the foundation of the Cycle Engineers' Institute (CEI) in 1898, which became the Incorporated Institution of Automobile Engineers (IAE) in 1906. The IAE became the Automotive Branc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-16
The General Dynamics F-16 Fighting Falcon is a single-engine Multirole combat aircraft, multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it evolved into a successful night fighter, all-weather multirole aircraft. Over 4,600 aircraft have been built since production was approved in 1976. Although no longer being purchased by the U.S. Air Force, improved versions are being built for export customers. In 1993, General Dynamics sold its aircraft manufacturing business to the Lockheed Corporation, which in turn became part of Lockheed Martin after a 1995 merger with Martin Marietta. The Fighting Falcon's key features include a frameless bubble canopy for good visibility, side-stick, side-mounted control stick to ease control while maneuvering, an ejection seat reclined 30 degrees from vertical to reduce the effect of g-forces on the Aircraft pilot, pilot, and the first use of a rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Entry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass (ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic speed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ONERA
The Office National d'Etudes et de Recherches Aérospatiales (ONERA) is the French national aerospace research centre. It is a public establishment with industrial and commercial operations, and carries out application-oriented research to support enhanced innovation and competitiveness in the aerospace and defense sectors. ONERA was created in 1946 as "Office National d’Études et de Recherches Aéronautiques". Since 1963, its official name has been "Office National d’Études et de Recherches Aérospatiales". However, in January 2007, ONERA has been dubbed "The French Aerospace Lab" to improve its international visibility. History ONERA's historic roots are in the Paris suburb of Meudon, south of Paris. As early as 1877, this site hosted an aeronautical research center for military aerostats (balloons): Etablissement central de l’aérostation militaire. ONERA was created in May 1946 to relaunch aeronautics research, an activity that had gone into hibernation during t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta-wing
A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (Δ). Although long studied, it did not find significant applications until the Jet Age, when it proved suitable for high-speed subsonic and supersonic flight. At the other end of the speed scale, the Rogallo flexible wing proved a practical design for the hang glider and other ultralight aircraft. The delta wing form has unique aerodynamic characteristics and structural advantages. Many design variations have evolved over the years, with and without additional stabilising surfaces. General characteristics Structure The long root chord of the delta wing and minimal structure outboard make it structurally efficient. It can be built stronger, stiffer and at the same time lighter than a swept wing of equivalent lifting capability. Because of this it is easy and relatively inexpensive to build – a substantial factor in the success of the MiG- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AGARD-B Wind Tunnel Model
AGARD-B is a standard wind tunnel model (calibration model) that is used to verify, by comparison of test results with previously published data, the measurement chain in a wind tunnel. Together with its derivative AGARD-C it belongs to a family of AGARD standard wind tunnel models. Its origin dates to the year 1952, and the Second Meeting of the AGARD Wind Tunnel and Model Testing Panel in Rome, Italy, when it was decided to define two standard wind tunnel model configurations (AGARD-A and AGARD-B) to be used for exchange of test data and comparison of test results of same models tested in different wind tunnels. The idea was to establish standards of comparison between wind tunnels and improve the validity of wind tunnel tests. Among the standard wind tunnel models, AGARD model configuration B (AGARD-B) has become by far the most popular. Initially intended for the supersonic wind tunnels, the AGARD-B configuration has since been tested in many wind tunnels at a wide range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
