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Air-start System
An air-start system is a power source used to provide the initial rotation to start large diesel and gas turbine engines. Diesel engines Direct starting Compared to a gasoline (petrol) engine, a diesel engine has a very high compression ratio, an essential design feature, as it is the heat of compression that ignites the fuel. An electric starter with sufficient power to "crank" a large diesel engine would itself be so large as to be impractical, thus the need for an alternative system. When starting the engine, compressed air is admitted to whichever cylinder has a piston just over top dead center, forcing it downward. As the engine starts to turn, the air-start valve on the next cylinder in line opens to continue the rotation. After several rotations, fuel is injected into the cylinders, the engine starts running and the air is cut off. To further complicate matters, a large engine is usually "blown over" first with zero fuel settings and the indicator cocks open, to prove t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starter (engine)
A starter (also self-starter, cranking motor, or starter motor) is a device used to rotate (crank) an internal-combustion engine so as to initiate the engine's operation under its own power. Starters can be electric, pneumatic, or hydraulic. The starter can also be another internal-combustion engine in the case, for instance, of very large engines, or diesel engines in agricultural or excavation applications. Internal combustion engines are feedback systems, which, once started, rely on the inertia from each cycle to initiate the next cycle. In a four-stroke engine, the third stroke releases energy from the fuel, powering the fourth (exhaust) stroke and also the first two (intake, compression) strokes of the next cycle, as well as powering the engine's external load. To start the first cycle at the beginning of any particular session, the first two strokes must be powered in some other way than from the engine itself. The starter motor is used for this purpose and it is not re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Starter GE J79-11A By BMW
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By mole fraction (i.e., by number of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air composition, temperature, and atmospheric pressure vary with altitude. Within the atmosphere, air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isopropyl Nitrate
Isopropyl nitrate (IPN, 2-propyl nitrate) is a colorless liquid monopropellant. It is used as a diesel cetane improver. IPN is a low-sensitivity explosive, with a detonation velocity of approximately 5400 m/s. Isopropyl nitrate is extremely flammable and burns with a practically invisible flame. This presents unique hazards in its handling. The flame is significantly less luminous than hydrogen or methanol flame and is only visible due to the turbulent hot air it generates. Isopropyl nitrate was previously used in a jet engine rapid starting system for military interceptor aircraft (a requirement for fast scrambling, as it provided simultaneous, near-instantaneous engine starting for twin engines) and was known as AVPIN. The exhaust fumes from an AVPIN monopropellant engine may themselves be explosive, if mixed with further air. Early systems, as used on the Gloster Javelin, used a simple pressurising cartridge and had a poor reputation for misfires, including engine-dest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Support Equipment
File:Qatar Airways Airbus A380-800 at Heathrow Airport Terminal 4 before Flying to Doha, 6 Jan 2015.jpg, Qatar Airways Airbus A380-800 on apron outside Heathrow Terminal 4 with a wide range of ground handling equipment around such as aircraft container, pallet loader, Unit load device, ULD, jet air starter, belt loader, pushback tug, catering vehicles, jet bridges, and dollies. File:CaribbeanAirlines738 POS.jpg, alt=Caribbean Airlines Boeing 737-800 with a ride range of Airport ground support equipment, Ground handling equipment at Piarco International Airport. Image:Airport equpment.JPG, Ground support equipment Image:KLM 777 pushback.jpg, Pushing a KLM Boeing 777 back Ground support equipment (GSE) is the support equipment found at an airport, usually on the apron, the servicing area by the terminal. This equipment is used to service the aircraft between flights. As the name suggests, ground support equipment is there to support the operations of aircraft whilst on the ground. ... [...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] |
Ground Support Equipment
File:Qatar Airways Airbus A380-800 at Heathrow Airport Terminal 4 before Flying to Doha, 6 Jan 2015.jpg, Qatar Airways Airbus A380-800 on apron outside Heathrow Terminal 4 with a wide range of ground handling equipment around such as aircraft container, pallet loader, Unit load device, ULD, jet air starter, belt loader, pushback tug, catering vehicles, jet bridges, and dollies. File:CaribbeanAirlines738 POS.jpg, alt=Caribbean Airlines Boeing 737-800 with a ride range of Airport ground support equipment, Ground handling equipment at Piarco International Airport. Image:Airport equpment.JPG, Ground support equipment Image:KLM 777 pushback.jpg, Pushing a KLM Boeing 777 back Ground support equipment (GSE) is the support equipment found at an airport, usually on the apron, the servicing area by the terminal. This equipment is used to service the aircraft between flights. As the name suggests, ground support equipment is there to support the operations of aircraft whilst on the ground. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Compressor
An air compressor is a pneumatic device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces more and more air into a storage tank, increasing the pressure. When the tank's pressure reaches its engineered upper limit, the air compressor shuts off. The compressed air, then, is held in the tank until called into use. The kinetic energy provided by the compressed air can be used for a variety of applications such as pneumatic tool as it is released air and the tank depressurizes. When tank pressure reaches its lower limit, the air compressor turns on again and re-pressurizes the tank. An air compressor must be differentiated from a pump because it works for any gas/air, while pumps work on a liquid. Classification Compressors may be classified according to the pressure delivered: # Low-pressure air compressors (LPACs), which have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bleed Air
Bleed air is compressed air taken from the compressor stage of a gas turbine upstream of its fuel-burning sections. Automatic air supply and cabin pressure controller (ASCPCs) valves bleed air from high or low stage engine compressor sections. Low stage air is used during high power setting operation, and high during descent and other low power setting operations. Bleed air from that system can be utilized for internal cooling of the engine, cross-starting another engine, engine and airframe anti-icing, cabin pressurization, pneumatic actuators, air-driven motors, pressurizing the hydraulic reservoir, and waste and water storage tanks. Some engine maintenance manuals refer to such systems as "customer bleed air". Bleed air is valuable in an aircraft for two properties: high temperature and high pressure (typical values are 200–250 °C and 275 kPa (40 PSI), for regulated bleed air exiting the engine pylon for use throughout the aircraft). Uses In civil aircraft, bleed air' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auxiliary Power Unit
An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115 V AC voltage at 400 Hz (rather than 50/60 Hz in mains supply), to run the electrical systems of the aircraft; others can produce 28 V DC voltage. APUs can provide power through single or three-phase systems. Transport aircraft History During World War I, the British Coastal class blimps, one of several types of airship operated by the Royal Navy, carried a ABC auxiliary engine. These powered a generator for the craft's radio transmitter and, in an emergency, could power an auxiliary air blower. One of the first military fixed-wing aircraft to use an APU was the British, World War 1, Supermarine Nighthawk, an anti-Zeppelin night fighter.Andrews and Morgan 1987, p. 21. During World War II, a number of large Ameri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric J79
The General Electric J79 is an axial-flow turbojet engine built for use in a variety of fighter and bomber aircraft and a supersonic cruise missile. The J79 was produced by General Electric Aircraft Engines in the United States, and under license by several other companies worldwide. Among its major uses was the F-104 Starfighter, B-58 Hustler, F-4 Phantom II, A-5 Vigilante and IAI Kfir. A commercial version, designated the CJ805, powered the Convair 880, while an aft-turbofan derivative, the CJ805-23, powered the Convair 990 airliners and a single Sud Aviation Caravelle intended to demonstrate to the U.S. market the benefits of a bypass engine over the existing Avon turbojet. In 1959 the gas generator of the J79 was developed as a stationary 10MW-class () free-turbine turboshaft engine for naval power, power generation, and industrial use, called the LM1500. Its first application was in the research hydrofoil . Development Evolution of the variable stator compressor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Starter
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By mole fraction (i.e., by number of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air composition, temperature, and atmospheric pressure vary with altitude. Within the atmosphere, air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel is une ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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