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Bell Model 8096B
The Bell Aerosystems Company XLR81 (Model 8096) was an American liquid-propellant rocket engine, which was used on the Agena upper stage. It burned UDMH and RFNA fed by a turbopump in a fuel rich gas generator cycle. The turbopump had a single turbine with a gearbox to transmit power to the oxidizer and fuel pumps. The thrust chamber was all-aluminum, and regeneratively cooled by oxidizer flowing through gun-drilled passages in the combustion chamber and throat walls. The nozzle was a titanium radiatively cooled extension. The engine was mounted on a hydraulic actuated gimbal which enabled thrust vectoring to control pitch and yaw. Engine thrust and mixture ratio were controlled by cavitating flow venturis on the gas generator flow circuit. Engine start was achieved by solid propellant start cartridge. Variants Starting as an air-launched missile engine and finishing as a multi-mission general propulsion for the space age, the basic design went through a series of itera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Gemini
Project Gemini () was the second United States human spaceflight program to fly. Conducted after the first American crewed space program, Project Mercury, while the Apollo program was still in early development, Gemini was conceived in 1961 and concluded in 1966. The Gemini spacecraft carried a two-astronaut crew. Ten Gemini crews and 16 individual astronauts flew low Earth orbit (LEO) missions during 1965 and 1966. Gemini's objective was the development of space travel techniques to support the Apollo mission to Moon landing, land astronauts on the Moon. In doing so, it allowed the United States to catch up and overcome the lead in human spaceflight capability the Soviet Union had obtained in the early years of the Space Race, by demonstrating mission endurance up to just under 14 days, longer than the eight days required for a round trip to the Moon; methods of performing extravehicular activity (EVA) without tiring; and the orbital maneuvers necessary to achieve space rendezv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminum
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JP-4 (fuel)
JP-4, or JP4 (for "Jet Propellant") was a jet fuel, specified in 1951 by the United States Department of Defense (MIL-DTL-5624). Its NATO code is F-40. It is also known as avtag. Usage JP-4 was a 50-50 kerosene-gasoline blend. It had a lower flash point than JP-1, but was preferred because of its greater availability. It was the primary U.S. Air Force jet fuel between 1951 and 1995. MC-77 is the Swedish military equivalent of JP-4. Mixture JP-4 was a mixture of aliphatic and aromatic hydrocarbons. It was a flammable transparent liquid with clear or straw color, and a kerosene-like smell. It evaporated easily and floated on water. Although it had a low flash point (), a lit match dropped into JP-4 would not ignite the mixture. JP-4 froze at , and its maximum burning temperature was . JP-4 was a non-conductive liquid, prone to build up static electricity when being moved through pipes and tanks. As it is volatile and has a low flash point, the static discharge could cause a fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convair B-58 Hustler
The Convair B-58 Hustler, designed and produced by American aircraft manufacturer Convair, was the first operational bomber capable of Mach 2 flight. The B-58 was developed during the 1950s for the United States Air Force (USAF) Strategic Air Command (SAC). To achieve the high speeds desired, Convair chose a delta wing design used by contemporary interceptors such as the Convair F-102. The bomber was powered by four General Electric J79 engines in underwing pods. It had no bomb bay; it carried a single nuclear weapon plus fuel in a combination bomb/fuel pod underneath the fuselage. Later, four external hardpoints were added, enabling it to carry up to five weapons such as one Mk 53 and four Mk 43 warheads. The B-58 entered service in March 1960, and flew for a decade with two SAC bomb wings: the 43rd Bombardment Wing and the 305th Bombardment Wing. It was considered difficult to fly, imposing a high workload upon its three-man crews. Designed to replace the subsonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its origins to 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established by transfer of personnel from the Army Air Forces with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in United States order of precedence, order of precedence. The United States Air Force articulates its core missions as air supremacy, intelligence, surveillance, target acquisition, and reconnaissance, global integrated intelligence, surveillance and reconnaissance, airlift, rapid global mobility, Strategic bombing, global strike, and command and control. The United States Department of the Air Force, Department of the Air Force, which serves as the USAF's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venturi Effect
The Venturi effect is the reduction in fluid pressure that results when a moving fluid speeds up as it flows from one section of a pipe to a smaller section. The Venturi effect is named after its discoverer, the Italian physicist Giovanni Battista Venturi, and was first published in 1797. The effect has various engineering applications, as the reduction in pressure inside the constriction can be used both for measuring the fluid flow and for moving other fluids (e.g. in a vacuum ejector). Background In inviscid fluid dynamics, an incompressible fluid's velocity must ''increase'' as it passes through a constriction in accord with the principle of mass continuity, while its static pressure must ''decrease'' in accord with the principle of conservation of mechanical energy (Bernoulli's principle) or according to the Euler equations. Thus, any gain in kinetic energy a fluid may attain by its increased velocity through a constriction is balanced by a drop in pressure because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavitation
Cavitation in fluid mechanics and engineering normally is the phenomenon in which the static pressure of a liquid reduces to below the liquid's vapor pressure, leading to the formation of small vapor-filled cavities in the liquid. When subjected to higher pressure, these cavities, called "bubbles" or "voids", collapse and can generate shock waves that may damage machinery. These shock waves are strong when they are very close to the imploded bubble, but rapidly weaken as they propagate away from the implosion. Cavitation is a significant cause of wear in some engineering contexts. Collapsing voids that implode near to a metal surface cause cyclic stress through repeated implosion. This results in surface fatigue of the metal, causing a type of wear also called "cavitation". The most common examples of this kind of wear are to pump impellers, and bends where a sudden change in the direction of liquid occurs. Cavitation is usually divided into two classes of behavior. ''In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Principal Axes
An aircraft in flight is free to rotate in three dimensions: '' yaw'', nose left or right about an axis running up and down; ''pitch'', nose up or down about an axis running from wing to wing; and ''roll'', rotation about an axis running from nose to tail. The axes are alternatively designated as ''vertical'', ''lateral'' (or ''transverse''), and ''longitudinal'' respectively. These axes move with the vehicle and rotate relative to the Earth along with the craft. These definitions were analogously applied to spacecraft when the first crewed spacecraft were designed in the late 1950s. These rotations are produced by torques (or moments) about the principal axes. On an aircraft, these are intentionally produced by means of moving control surfaces, which vary the distribution of the net aerodynamic force about the vehicle's center of gravity. Elevators (moving flaps on the horizontal tail) produce pitch, a rudder on the vertical tail produces yaw, and ailerons (flaps on the wings t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Vectoring
Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to Aircraft flight control system, control the Spacecraft attitude control, attitude or angular velocity of the vehicle. In rocketry and ballistic missiles that fly outside the atmosphere, aerodynamic Flight control surfaces, control surfaces are ineffective, so thrust vectoring is the primary means of Flight dynamics (fixed-wing aircraft), attitude control. Exhaust vanes and Gimbaled thrust, gimbaled engines were used in the 1930s by Robert H. Goddard, Robert Goddard. For aircraft, the method was originally envisaged to provide upward vertical thrust as a means to give aircraft vertical (VTOL) or short (STOL) takeoff and landing ability. Subsequently, it was realized that using vectored thrust in combat situations enabled aircraft to perform various maneuvers not available to conventional-en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gimbaled Thrust
Gimbaled thrust is the system of thrust vectoring used in most rockets, including the Space Shuttle program, Space Shuttle, the Saturn V lunar rockets, and the Falcon 9. Operation In a gimbaled thrust system, the engine or just the exhaust nozzle of the rocket can be swiveled on two axes (Pitch yaw roll, pitch and yaw) from side to side. As the nozzle is moved, the direction of the thrust is changed relative to the center of gravity of the rocket. The diagram illustrates three cases. The middle rocket shows the straight-line flight configuration in which the direction of thrust is along the center line of the rocket and through the center of gravity of the rocket. On the rocket at the left, the nozzle has been deflected to the left and the thrust line is now inclined to the rocket center line at an angle called the gimbal angle. Since the thrust no longer passes through the center of gravity, a torque is generated about the center of gravity and the nose of the rocket turns to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiative Cooling
In the study of heat transfer, radiative cooling is the process by which a body loses heat by thermal radiation. As Planck's law describes, every physical body spontaneously and continuously emits electromagnetic radiation. Radiative cooling has been applied in various contexts throughout human history, including Ice-making, ice making in India and Iran, Heat shield, heat shields for spacecraft, and in architecture. In 2014, a scientific breakthrough in the use of Photonic metamaterial, photonic metamaterials made daytime radiative cooling possible. It has since been proposed as a strategy to mitigate local and global warming caused by greenhouse gas emissions known as passive daytime radiative cooling. Terrestrial radiative cooling Mechanism Infrared radiation can pass through dry, clear air in the wavelength range of 8–13 μm. Materials that can absorb energy and radiate it in those wavelengths exhibit a strong cooling effect. Materials that can also reflect 95% or mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium
Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of minerals, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere; it is found in almost all living things, as well as bodies of water, rocks, and soils. The metal is extracted from its principal mineral ores by the Kroll and Hunter processes. The most common compound, titanium dioxide (TiO2), is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and cata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
