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Fuel Economy In Aircraft
The fuel economy in aircraft is the measure of the energy efficiency in transport, transport energy efficiency of aircraft. Fuel efficiency is increased with better aerodynamics and by reducing weight, and with improved engine brake-specific fuel consumption and propulsive efficiency or thrust-specific fuel consumption. Endurance (aeronautics), Endurance and Range (aeronautics), range can be maximized with the optimum airspeed, and economy is better at optimum altitudes, usually higher. An airline efficiency depends on its fleet fuel burn, airline seating, seating density, air cargo and passenger load factor, while operational procedures like aircraft maintenance, maintenance and Airway (aviation), routing can save fuel. Average fuel burn of new aircraft fell 45% from 1968 to 2014, a compounded annual reduction 1.3% with a variable reduction rate. In 2018, CO₂ emissions totalled 747 million tonnes for passenger transport, for 8.5 trillion revenue passenger kilometres (RPK), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aviation Efficiency (RPK Per Kg CO2)
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' include Airplane, fixed-wing and Helicopter, rotary-wing types, morphable wings, wing-less lifting bodies, as well as Aerostat, lighter-than-air aircraft such as Balloon (aeronautics), hot air balloons and airships. Aviation began in the 18th century with the development of the hot air balloon, an apparatus capable of atmospheric displacement through buoyancy. Clément Ader built the "Ader Éole" in France and made an uncontrolled, powered hop in 1890. This was the first powered aircraft, although it did not achieve controlled flight. Some of the most significant advancements in aviation technology came with the controlled gliding flying of Otto Lilienthal in 1896. A major leap followed with the construction of the ''Wright Flyer'', the first powered airplane by the Wright brothers in the early 1900s. Since that time, aviation has been technologically revolutionized by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Maintenance
Aircraft maintenance is the performance of tasks required to ensure the continuing airworthiness of an aircraft or aircraft part, including overhaul, inspection, replacement, defect rectification, and the embodiment of modifications, compliance with airworthiness directives and repair. Regulation The maintenance of aircraft is highly regulated, in order to ensure safe and correct functioning during flight. In civil aviation national regulations are coordinated under international standards, established by the International Civil Aviation Organization (ICAO). The ICAO standards have to be implemented by local airworthiness authorities to regulate the maintenance tasks, personnel and inspection system. Maintenance staff must be licensed for the tasks they carry out. Major airworthiness regulatory authorities include the US Federal Aviation Administration (FAA), European Union Aviation Safety Agency (EASA), Australian Transport Safety Bureau (ATSB), Transport Canada (TC) and I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamic Lift
When a fluid flows around an object, the fluid exerts a force on the object. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it is defined to act perpendicular to the flow and therefore can act in any direction. If the surrounding fluid is air, the force is called an aerodynamic force. In water or any other liquid, it is called a hydrodynamic force. Dynamic lift is distinguished from other kinds of lift in fluids. Aerostatic lift or buoyancy, in which an internal fluid is lighter than the surrounding fluid, does not require movement and is used by balloons, blimps, dirigibles, boats, and submarines. Planing lift, in which only the lower portion of the body is immersed in a liquid flow, is used by motorboats, surfboards, windsurfers, sailb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powered Aircraft
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many small UAVs have used electric motors. Manufacturing industry The largest manufacturer of turboprop engines for general aviation is Pratt & Whitney. General Electric announced in 2015 entrance into the market. Development history * 1903: Manly-Balzer engine sets standards for later radial engines. * 1910: Coandă-1910, an unsuccessful ducted fan aircraft exhibited at Paris Aero Salon, powered by a piston engine. The aircraft never flew, but a patent was filed for routing exhaust gases into the duct to augment thrust. * 1914: Auguste Rateau suggests using exhaust-powered compressor – a turbocharger – to improve high-altitude performance; not accepted after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forces2
In physics, a force is an influence that can cause an object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity. The SI unit of force is the newton (N), and force is often represented by the symbol . Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include elastic, frictional, contact or "normal" forces, and gravitational. The rotational version of force is torque, which produces changes in the rotational speed of an object. In an extended body, each part applies forces on the adjacent parts; the distribution of such forces through the body is the internal mechanical stress. In the case of multiple forces, if the net force on an extended body is zero the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airframe
The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system. Airframe design is a field of aerospace engineering that combines aerodynamics, materials technology and manufacturing methods with a focus on weight, strength and aerodynamic drag, as well as reliability and cost.Michael C. Y. Niu (1988). ''Airframe Structural Design''. Conmilit Press LTD. History Modern airframe history began in the United States during the Wright Flyer's maiden flight, showing the potential of fixed-wing designs in aircraft. In 1912 the Deperdussin Monocoque pioneered the light, strong and streamlined monocoque fuselage formed of thin plywood layers over a circular frame, achieving . First World War Many early developments were spurred by military needs during World War I. Well known aircraft from that era include the Dutch designer Anthony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Aircraft
An electric aircraft is an aircraft powered by electricity. Electric aircraft are seen as a way to reduce the environmental effects of aviation, providing zero emissions and quieter flights. Electricity may be supplied by a variety of methods, the most common being electric battery, batteries. Most have electric motors driving propellers or turbines. Crewed flights in an electrically powered airship go back to the 19th century, and to 1917 for a tethered helicopter. Model aircraft#Electric power, Electrically powered model aircraft have been flown at least since 1957, preceding the small unmanned aerial vehicles (UAV) or drones used today. Small Unmanned aircraft system, UAS could be used for parcel deliveries, and larger ones for long-endurance applications: aerial imagery, surveillance, telecommunications. The first crewed free flight by an electrically powered aeroplane, the Militky MB-E1, MB-E1, was made in 1973, and most crewed electric aircraft today are still only e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid Electric Aircraft
A hybrid electric aircraft is an aircraft with a Hybrid electric vehicle, hybrid electric powertrain. As the energy density of lithium-ion batteries is much lower than aviation fuel, a hybrid electric powertrain may effectively increase flight range compared to pure electric aircraft. By May 2018, there were over 30 hybrid electric aircraft projects, and short-haul hybrid-electric airliners were envisioned from 2032. History The Boeing Truss-Braced Wing subsonic concept was planned with hybrid electric propulsion. The Diamond DA36 E-Star first flew on 8 June 2011, the first flight of a series hybrid powertrain, reducing fuel consumption and emissions by up to 25%, a technology scalable to a 100-seater airliner. A small and lighter Austro Engine 40 hp (30 kW) Wankel engine generates the electricity, supplemented by EADS batteries for silent take off, feeding a Siemens 70 kW (94 hp) electric motor turning the propeller. The AgustaWestland Project Zero was inten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Rotor
A propfan, also called an open rotor engine, open fan engine is an aircraft engine combining features of turbofans and turboprops. It uses advanced, curved propeller blades without a duct. Propfans aim to combine the speed capability of turbofans with the fuel efficiency of turboprops, especially at high subsonic speeds. It is sometimes called a "ultra-high-bypass (UHB) turbofan". Definition In the 1970s, Hamilton Standard described its propfan as "a small diameter, highly loaded multiple bladed variable pitch propulsor having swept blades with thin advanced airfoil sections, integrated with a nacelle contoured to retard the airflow through the blades thereby reducing compressibility losses and designed to operate with a turbine engine and using a single stage reduction gear resulting in high performance". In 1982, the weekly aviation magazine Flight International defined the propfan as a propeller with 8–10 highly swept blades that cruised at a speed of , although it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geared Turbofan
The geared turbofan is a type of turbofan aircraft engine with a planetary gearbox between the low pressure compressor / turbine and the fan, enabling each to spin at its optimum speed. The benefit of the design is lower fuel consumption and much quieter operation. The drawback is that it increases weight and adds complexity. Technology In a conventional turbofan, a single shaft (the "low-pressure" or LP shaft) connects the fan, the low-pressure compressor and the low-pressure turbine (a second concentric shaft connects the high-pressure compressor and high-pressure turbine). In this configuration, the maximum tip speed for the larger radius fan limits the rotational speed for the LP shaft and thus the LP compressor and turbine. At high bypass ratios (and thus also high radius ratios) the rotational speed of the LP turbine and compressor must be relatively low, which means extra compressor and turbine stages are required to keep the average stage loadings and, therefore, overa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bypass Ratio
The bypass ratio (BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for every 1 kg of air passing through the core. Turbofan engines are usually described in terms of BPR, which together with engine pressure ratio, turbine inlet temperature and fan pressure ratio are important design parameters. In addition, BPR is quoted for turboprop and unducted fan installations because their high propulsive efficiency gives them the overall efficiency characteristics of very high bypass turbofans. This allows them to be shown together with turbofans on plots which show trends of reducing specific fuel consumption (SFC) with increasing BPR. BPR is also quoted for lift fan installations where the fan airflow is remote from the engine and doesn't physically touch the engine core. Bypass provides a lower fuel consumption ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overall Pressure Ratio
In aeronautical engineering, overall pressure ratio, or overall compression ratio, is the amount of times the pressure increases due to ram compression and the work done by the compressor stages. The compressor pressure ratio is the ratio of the stagnation pressures at the front and rear of the compressor of a gas turbine. Overall pressure ratio in a high-bypass turbofan is a function of inlet pressure ratio and compressor pressure ratio: OPR = IPR \times CPR The terms ''compression ratio'' and ''pressure ratio'' are used interchangeably. Advantages of high overall pressure ratios As can be seen in the formula for maximum theoretical thermal efficiency in an ideal Brayton cycle engine, a high pressure ratio leads to higher thermal efficiency: \eta = 1-\left(\frac\right) where PR is the pressure ratio and gamma the heat capacity ratio of the fluid, 1.4 for air. Keep in mind that pressure ratio scales exponentially with the number of compressor stages. Imagine a gas turbin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
