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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 engines and gas turbines. 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 turn a large diesel engine would itself be so large as to be impractical so there is a need for an alternative system. An air start system has three main components along with various safety components, namely the air start injector, the distributor and the air receivers. When the system is initiated, starting air from the receivers is distributed by the distributor unit to each respective air start valve according to the firing order of the engine’s cylinders. Safety components include flame traps, to prevent air line explosions, a turning gear interlock which ensures that air-start cannot be initiated when 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 motor, electric, pneumatic motor, pneumatic, or hydraulic motor, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bleed Air
Bleed air in aerospace engineering 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 (ASCPC) valves bleed air from low or high stage engine compressor sections; low stage air is used during high power setting operation, and high stage air is used 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 and , for regulated bleed air exiting the engine pylon for use throughout the aircraft). Uses In civil aircraft, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Components Of Jet Engines
This article briefly describes the components and systems found in jet engines. Major components Major components of a turbojet including references to turbofans, turboprops and turboshafts: *Cold section: **Air intake (inlet) — For subsonic aircraft, the inlet is a duct which is required to ensure smooth airflow into the engine despite air approaching the inlet from directions other than straight ahead. This occurs on the ground from cross winds and in flight with aircraft pitch and yaw motions. The duct length is minimised to reduce drag and weight. Air enters the compressor at about half the speed of sound so at flight speeds lower than this the flow will accelerate along the inlet and at higher flight speeds it will slow down. Thus the internal profile of the inlet has to accommodate both accelerating and diffusing flow without undue losses. For supersonic aircraft, the inlet has features such as cones and ramps to produce the most efficient series of shockwaves which for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Engine Starting
Many variations of aircraft engine starting have been used since the Wright brothers made their first powered flight in 1903. The methods used have been designed for weight saving, simplicity of operation and reliability. Early piston engines were started by hand. Geared hand starting, electrical and cartridge-operated systems for larger engines were developed between the First and Second World Wars. Gas turbine aircraft engines such as turbojets, turboshafts and turbofans often use air/pneumatic starting, with the use of ''bleed air'' from built-in auxiliary power units (APUs) or external air compressors now seen as a common starting method. Often only one engine needs be started using the APU (or remote compressor). After the first engine is started using APU bleed air, ''cross-bleed air'' from the running engine can be used to start the remaining engine(s). Piston engines Hand starting/propeller swinging Hand starting of aircraft piston engines by swinging the propeller is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coffman Engine Starter
The Coffman engine starter (also known as a "shotgun starter") was a starting system used on many piston engines in aircraft and armored vehicles of the 1930s and 1940s. It used a cordite cartridge to move a piston, which cranked the engine. The Coffman system was one of the most common brands; another was the Breeze cartridge system, which was produced under Coffman patents. Most American military aircraft and tanks which used radial engines were equipped with this system. Some versions of the Rolls-Royce Merlin engine used in the British Supermarine Spitfire used the Coffman system as a starter. The Hawker Typhoon and Hawker Tempest also used the Coffman system to start their Napier Sabre engines. Cartridge starters used on a number of jet engines, including such engines as the Rolls-Royce Avon, which were used in the English Electric Canberra and Hawker Hunter aircraft, used a high gas volume cartridge driving a turbine instead of a piston. Some Snowcat and similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isopropyl Nitrate
In organic chemistry, a propyl group is a three-carbon alkyl substituent with chemical formula for the linear form. This substituent form is obtained by removing one hydrogen atom attached to the terminal carbon of propane. A propyl substituent is often represented in organic chemistry with the symbol Pr (not to be confused with the element praseodymium). An isomeric form of propyl is obtained by moving the point of attachment from a terminal carbon atom to the central carbon atom, named isopropyl or 1-methylethyl. To maintain four substituents on each carbon atom, one hydrogen atom has to be moved from the middle carbon atom to the carbon atom which served as attachment point in the ''n''-propyl variant, written as . Linear propyl is sometimes termed normal and hence written with a prefix ''n''- (i.e., ''n-''propyl), as the absence of the prefix ''n''- does not indicate which attachment point is chosen, i.e. absence of prefix does not automatically exclude the possibility of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Support Equipment
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. The role of this equipment generally involves ground power operations, aircraft mobility, and cargo/passenger loading operations. Many airlines subcontract ground handling to an airport or a handling agent, or even to another airline. Ground handling addresses the many service requirements of a passenger aircraft between the time it arrives at a terminal gate and the time it departs for its next flight. Speed, efficiency, and accuracy are important in ground handling services in order to minimize the turnaround time (the time during which the aircraft remains parked at the gate). Small airlines sometimes subcontract maintenance to a larger carrier, as it may be a bett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Index Of Aviation Articles
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Articles related to aviation include: A Aviation accidents and incidents – Above Mean Sea Level (AMSL) – ADF – Accessory drive – Advance airfield – Advanced air mobility – Advanced technology engine – Adverse yaw – Aerial ramming – Aerial reconnaissance – Aerobatics – Aerodrome – Aerodrome mapping database (AMDB) – Aerodynamics – Aerofoil – Aerodrome beacon – Aeronautical Information Manual (AIM) – Aeronautical chart – Aeronautical Message Handling System – Aeronautical phraseology – Aeronautics – Aeronaval – Aerospace – Aerospace engineering – Afterburner – Agile Combat Employment (ACE) – Aileron – Air charter – Air defense identification zone (ADIZ) – Air freight terminal – Air traffic flow management – Air-augmented rocket – Airband – Airbase (AFB) – Airborne colli ... [...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
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. The role of this equipment generally involves ground power operations, aircraft mobility, and cargo/passenger loading operations. Many airlines subcontract ground handling to an airport or a handling agent, or even to another airline. Ground handling addresses the many service requirements of a passenger aircraft between the time it arrives at a terminal gate and the time it departs for its next flight. Speed, efficiency, and accuracy are important in ground handling services in order to minimize the turnaround time (the time during which the aircraft remains parked at the gate). Small airlines sometimes subcontract maintenance to a larger carrier, as it may be a bett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Compressor
An air compressor is a machine that takes ambient air from the surroundings and discharges it at a higher pressure. It is an application of a gas compressor and a Pneumatics, pneumatic device that energy conversion, converts mechanical power (from an electric motor, Diesel engine, diesel or gasoline engine, etc.) into potential energy stored in compressed air, which has many uses. A common application is to compress air into a storage tank, for immediate or later use. When the delivery pressure reaches its set upper limit, the compressor is shut off, or the excess air is released through an overpressure valve. The compressed air is stored in the tank until it is needed. The pressure energy provided by the compressed air can be used for a variety of applications such as pneumatic tools as it is released. When tank pressure reaches its lower limit, the air compressor turns on again and re-pressurizes the tank. A compressor is different from a pump because it works on a gas, while pum ... [...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. A jet fuel starter (JFS) is a similar device to an APU but directly linked to the main engine and started by an onboard compressed air bottle. 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
