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Avrocar (aircraft)
The Avro Canada VZ-9 Avrocar was a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single "turborotor" blowing exhaust out of the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer. Originally designed as a fighter-like aircraft capable of very high speeds and altitudes, the project was repeatedly scaled back over time and the U.S. Air Force eventually abandoned it. Development was then taken up by the U.S. Army for a tactical combat aircraft requirement, a sort of high-performance helicopter.Milberry 1979, p. 137. In flight testing, the Avrocar proved to have unresolved thrust and stability problems that limited it to a degraded, low-performance flight envelope; subsequently, the project was cancelled in September 1961. Through the history of the program, the project was ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Concept
Proof of concept (POC or PoC), also known as proof of principle, is a realization of a certain method or idea in order to demonstrate its feasibility, or a demonstration in principle with the aim of verifying that some concept or theory has practical potential. A proof of concept is usually small and may or may not be complete. These collaborative trials aim to test feasibility of business concepts and proposals to solve business problems and accelerate business innovation goals. A proof of value (PoV) is sometimes used along proof of concept, and differs by focusing more on demonstrating the potential customers use case and value, and is usually less in-depth than a proof of concept. Usage history The term has been in use since 1967. In a 1969 hearing of the Committee on Science and Astronautics, Subcommittee on Advanced Research and Technology, ''proof of concept'' was defined as following: One definition of the term "proof of concept" was by Bruce Carsten in the context o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Havilland Vampire
The de Havilland Vampire is a British jet fighter which was developed and manufactured by the de Havilland, de Havilland Aircraft Company. It was the second jet fighter to be operated by the Royal Air Force, RAF, after the Gloster Meteor, and the first to be powered by a single jet propulsion, jet engine. Development of the Vampire as an experimental aircraft began in 1941 during the Second World War, to exploit the revolutionary innovation of jet propulsion. From the company's design studies, it was decided to use a single-engine, twin-boom aircraft, powered by the de Havilland Goblin, Halford H.1 turbojet (later produced as the Goblin). Aside from its propulsion system and twin-boom configuration, it was a relatively conventional aircraft. In May 1944 it was decided to produce the aircraft as an interceptor aircraft, interceptor for the Royal Air Force (RAF). In 1946 the Vampire entered operational service with the RAF, only months after the war had ended. The Vampire quick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Playing Card
A playing card is a piece of specially prepared card stock, heavy paper, thin cardboard, plastic-coated paper, cotton-paper blend, or thin plastic that is marked with distinguishing motifs. Often the front (face) and back of each card has a finish to make handling easier. They are most commonly used for playing card games, and are also used in magic tricks, cardistry, card throwing, and card houses; cards may also be collected. Some patterns of Tarot playing card are also used for divination, although bespoke cards for this use are more common. Playing cards are typically palm-sized for convenient handling, and usually are sold together in a set as a deck of cards or pack of cards. The most common type of playing card in the West is the French-suited, standard 52-card pack, of which the most widespread design is the English pattern, followed by the Belgian-Genoese pattern. However, many countries use other, traditional types of playing card, including those that are German ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spades (suit)
Spades form one of the four suits of playing cards in the standard French deck. It is the same shape as the leaf symbol in German-suited cards but looks like a black heart turned upside down with a stalk at its base. It symbolises the pike or halberd, two medieval weapons. In French the suit of Spades is known as the ''Pique'' and in German as the ''Pik''. It corresponds to the suit of Leaves (''Laub'', ''Grün'', ''Schippen'' or, in Bavaria, ''Gras'') in the German suited playing cards. In Switzerland, the suit is known as ''Schuufle'' ("shovel") and in many German regions, e.g. the Rhineland as ''Schüppe/Schippe'' ("shovel"). In Bridge, Spades rank as the highest suit. In Skat and similar games, it is the second-highest suit. Name The French name for this suit, '' pique'' ("pike"), meant, in the 14th century, a weapon formed by an iron spike placed at the end of a pike. For playing cards, the term may have been coined by analogy with the Latin symbol from which it is d ... [...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 Mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power-to-weight Ratio
Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement of actual performance of any engine or power source. It is also used as a measurement of performance of a vehicle as a whole, with the engine's power output being divided by the weight (or mass) of the vehicle, to give a metric that is independent of the vehicle's size. Power-to-weight is often quoted by manufacturers at the peak value, but the actual value may vary in use and variations will affect performance. The inverse of power-to-weight, weight-to-power ratio (power loading) is a calculation commonly applied to aircraft, cars, and vehicles in general, to enable the comparison of one vehicle's performance to another. Power-to-weight ratio is equal to thrust per unit mass multiplied by the velocity of any vehicle. Power-to-weight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero-length Launch
The zero-length launch system or zero-length take-off system (ZLL, ZLTO, ZEL, ZELL) was a method whereby jet fighters and attack aircraft could be near-vertically launched using rocket motors to rapidly gain speed and altitude. Such rocket boosters were limited to a short-burn duration, being typically solid-fuel and suitable for only a single use, being intended to drop away once expended. The majority of ZELL experiments, which including the conversion of several front-line combat aircraft for trialling the system, occurred during the 1950s amid the formative years of the Cold War. As envisioned, the operational use of ZELL would have employed mobile launch platform to disperse and hide aircraft, reducing their vulnerability in comparison to being centralised around established airbases with well-known locations. While flight testing had proved such systems to be feasible for combat aircraft, no ZELL-configured aircraft were ever used operationally. The emergence of ever-capabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Y Mockup Colour
A project is any undertaking, carried out individually or collaboratively and possibly involving research or design, that is carefully planned to achieve a particular goal. An alternative view sees a project managerially as a sequence of events: a "set of interrelated tasks to be executed over a fixed period and within certain cost and other limitations". A project may be a temporary (rather than a permanent) social system (work system), possibly staffed by teams (within or across organizations) to accomplish particular tasks under time constraints. A project may form a part of wider programme management or function as an ''ad hoc'' system. Note that open-source software "projects" or artists' musical "projects" (for example) may lack defined team-membership, precise planning and/or time-limited durations. Overview The word ''project'' comes from the Latin word ''projectum'' from the Latin verb ''proicere'', "before an action," which in turn comes from ''pro-'', which de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrifugal Fan
A centrifugal fan is a mechanical device for moving air or other gases in a direction at an angle to the incoming fluid. Centrifugal fans often contain a ducted housing to direct outgoing air in a specific direction or across a heat sink; such a fan is also called a blower, blower fan, or squirrel-cage fan (because it looks like a hamster wheel). Tiny ones used in computers are sometimes called biscuit blowers. These fans move air from the rotating inlet of the fan to an outlet. They are typically used in ducted applications to either draw air through ductwork/heat exchanger, or push air through similar. impellers. Compared to standard axial fans, they can provide similar air movement from a smaller fan package, and overcome higher resistance in air streams. Centrifugal fans use the kinetic energy of the impellers to move the air stream, which in turn moves against the resistance caused by ducts, dampers and other components. Centrifugal fans displace air radially, changing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrifugal Compressor
Centrifugal compressors, sometimes called impeller compressors or radial compressors, are a sub-class of dynamic axisymmetric work-absorbing turbomachinery. They achieve pressure rise by adding energy to the continuous flow of fluid through the rotor/impeller. The following equation shows this specific energy input. A substantial portion of this energy is kinetic which is converted to increased potential energy/static pressure by slowing the flow through a diffuser. The static pressure rise in the impeller may roughly equal the rise in the diffuser. Equation-0.1 : H = \left( \left( R \right)_2 - \left( R \right)_1 \right) :where the control volume nomenclature (illustrated in Figure-0.4) is: ::* subscript, is the impeller inlet location, station1 ::* subscript, is the impeller discharge/exit location, station2 ::* is the energy input per unit mass, units=(LP/m) ::* is the impeller's rotation speed, units=(radians/t) ::* is the radius of specified location, units=(L) ::* is ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flame Can
A flame (from Latin ''flamma'') is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction taking place in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density they are then considered plasma. Mechanism Color and temperature of a flame are dependent on the type of fuel involved in the combustion, as, for example, when a lighter is held to a candle. The applied heat causes the fuel molecules in the candle wax to vaporize (if this process happens in inert atmosphere without oxidizer, it is called pyrolysis). In this state they can then readily react with oxygen in the air, which gives off enough heat in the subsequent exothermic reaction to vaporize yet more fuel, thus sustaining a consistent flame. The high temperature of the flame causes the vaporized fuel molecules to decompose, forming various incomplete combustion products and free radicals, and these products then react with each other and with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Whittle
Air Commodore Sir Frank Whittle, (1 June 1907 – 8 August 1996) was an English engineer, inventor and Royal Air Force (RAF) air officer. He is credited with inventing the turbojet engine. A patent was submitted by Maxime Guillaume in 1921 for a similar invention which was technically unfeasible at the time. Whittle's jet engines were developed some years earlier than those of Germany's Hans von Ohain, who designed the first-to-fly (but never operational) turbojet engine. Whittle demonstrated an aptitude for engineering and an interest in flying from an early age. At first he was turned down by the RAF but, determined to join the force, he overcame his physical limitations and was accepted and sent to No. 2 School of Technical Training to join No 1 Squadron of Cranwell Aircraft Apprentices. He was taught the theory of aircraft engines and gained practical experience in the engineering workshops. His academic and practical abilities as an Aircraft Apprentice earned him a place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
