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Variable Cycle Engine
A variable cycle engine (VCE), also referred to as adaptive cycle engine (ACE), is an aircraft jet engine that is designed to operate efficiently under mixed flight conditions, such as subsonic, transonic and supersonic. The next generation of supersonic transport (SST) may require some form of VCE. To keep aircraft drag at supercruise down, SST engines require a high specific thrust (net thrust/airflow) to keep the cross-sectional area of the powerplant to a minimum. This implies a high jet velocity not only at supersonic cruise, but at take-off, which makes the aircraft noisy. A high specific thrust engine has a high jet velocity by definition, as the following approximate equation for net thrust implies: :F_\text = \dot \left(V_\text - V_\text\right) where: : \dot = \fracm,\, intake mass flow rate : V_\text,\, fully expanded jet velocity (in the exhaust plume) : V_\text,\, aircraft flight velocity Rearranging the above equation, specific thrust is given by: : \frac = V_\t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Fuel Efficiency
Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process. In the context of transport, fuel economy is the energy efficiency of a particular vehicle, given as a ratio of distance traveled per unit of fuel consumed. It is dependent on several factors including engine efficiency, transmission design, and tire design. In most countries, using the metric system, fuel economy is stated as "fuel consumption" in liters per 100 kilometers (L/100 km) or k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Lockheed Martin F-22 Raptor
The Lockheed Martin F-22 Raptor is an American single-seat, twin-engine, all-weather stealth tactical fighter aircraft developed for the United States Air Force (USAF). As the result of the USAF's Advanced Tactical Fighter (ATF) program, the aircraft was designed as an air superiority fighter, but also has ground attack, electronic warfare, and signals intelligence capabilities. The prime contractor, Lockheed Martin, built most of the F-22's airframe and weapons systems and conducted final assembly, while Boeing provided the wings, aft fuselage, avionics integration, and training systems. The aircraft first flew in 1997 and was variously designated F-22 and F/A-22 before it formally entered service in December 2005 as the F-22A. Although the USAF had originally planned to buy a total of 750 ATFs, the program was cut to 187 operational aircraft in 2009 due to high costs, a lack of air-to-air missions due to the focus on counterinsurgency operations at the time of product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Pratt & Whitney F119
The Pratt & Whitney F119, company designation PW5000, is an afterburning turbofan engine developed by Pratt & Whitney for the Advanced Tactical Fighter (ATF) program, which resulted in the Lockheed Martin F-22 Raptor. The engine delivers thrust in the class and was designed for sustained supersonic flight without afterburners, or supercruise. Delivering almost 22% more thrust with 40% fewer parts than its F100 predecessor, the F119 allows the F-22 to achieve supercruise speeds of up to Mach 1.8.F-22 Flight Test Data . accessed August 8, 2007. The F119's nozzles incorporate thrust vectoring that enable them to direct the engine thrust ±20° in the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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USAF
The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps (United States Army), Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 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 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 Air Force is a military service branch organized within the United States Department of the Air Force, De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Northrop YF-23
The Northrop/McDonnell Douglas YF-23 is an American single-seat, twin-engine stealth fighter aircraft technology demonstrator designed for the United States Air Force (USAF). The design was a finalist in the USAF's Advanced Tactical Fighter (ATF) competition, battling the Lockheed YF-22 for a production contract. Two YF-23 prototypes were built, nicknamed "Black Widow II" and "Gray Ghost". In the 1980s, the USAF began looking for a replacement for its fighter aircraft, especially to counter the USSR's advanced Sukhoi Su-27 and Mikoyan MiG-29. Several companies submitted design proposals; the USAF selected proposals from Northrop and Lockheed. Northrop teamed with McDonnell Douglas to develop the YF-23, while Lockheed, Boeing, and General Dynamics developed the YF-22. The YF-23 was stealthier and faster, but less agile than its competitor. After a four-year development and evaluation process, the YF-22 was announced the winner in 1991 and entered production as the Lockheed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Lockheed YF-22
The Lockheed/Boeing/General Dynamics YF-22 is an American single-seat, twin-engine fighter aircraft technology demonstrator designed for the United States Air Force (USAF). The design was a finalist in the USAF's Advanced Tactical Fighter competition, and two prototypes were built for the demonstration/validation phase of the competition. The YF-22 won the contest against the Northrop YF-23, and entered production as the Lockheed Martin F-22 Raptor. The YF-22 has a similar aerodynamic layout and configuration as the F-22, but with differences in the position and design of the cockpit, tail fins and wings, and in internal structural layout. In the 1980s, the USAF began looking for a replacement for its fighter aircraft, especially to counter the advanced Su-27 and MiG-29. A number of companies, divided into two teams, submitted their proposals. Northrop and McDonnell Douglas submitted the YF-23. Lockheed, Boeing and General Dynamics proposed and built the YF-22, which, alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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General Electric YF120
The General Electric YF120, internally designated as GE37, was a variable cycle afterburning turbofan engine designed by General Electric Aircraft Engines in the late 1980s and early 1990s for the United States Air Force's Advanced Tactical Fighter (ATF) program. It was designed to produce maximum thrust in the class. Prototype engines were installed in the two competing technology demonstrator aircraft, the Lockheed YF-22 and Northrop YF-23. Pratt & Whitney's competing F119 was selected over the F120 to power the ATF, the competition for which the Lockheed team won, and became F-22 Raptor. History Development General Electric (GE) began developing the GE37, which would become basis of the XF120 and YF120, for the Joint Advanced Fighter Engine (JAFE) program in the early 1980s aimed at supplying the powerplant for the Air Force's Advanced Tactical Fighter (ATF). The core technology used in the F120 design was developed during two industry-government programs, the Advanced T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energy, digital industry, additive manufacturing and venture capital and finance, but has since divested from several areas, now primarily consisting of the first four segments. In 2020, GE ranked among the Fortune 500 as the 33rd largest firm in the United States by gross revenue. In 2011, GE ranked among the Fortune 20 as the 14th most profitable company, but later very severely underperformed the market (by about 75%) as its profitability collapsed. Two employees of GE – Irving Langmuir (1932) and Ivar Giaever (1973) – have been awarded the Nobel Prize. On November 9, 2021, the company announced it would divide itself into three investment-grade public companies. On July 18, 2022, GE unveiled the brand names of the companies it wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Next Generation Air Dominance
The Next Generation Air Dominance (NGAD) is a United States Air Force (USAF) sixth-generation air superiority initiative with a goal of fielding a "family of systems" that is to succeed the Lockheed Martin F-22 Raptor. A manned fighter aircraft is the centerpiece program of NGAD and has been referred to as the F-X or Penetrating Counter-Air (PCA) and is to be supported by uncrewed "Loyal Wingman" platforms through manned-unmanned teaming (MUM-T). The NGAD originates from DARPA's Air Dominance Initiative study in 2014, and is expected to field the new fighter aircraft in the 2030s. While having an identical name and sharing some technology developments, the program is distinct from the U.S. Navy's NGAD program, which has the F/A-XX as its fighter component and would have a similar fielding timeframe. History The NGAD was initiated in 2014 to develop a 2030s air superiority system for the U.S. Air Force. DARPA had completed its Air Dominance Initiative study in March 2014 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Pratt & Whitney XA101
The Pratt & Whitney XA101 is an American adaptive cycle engine demonstrator being developed by Pratt & Whitney for the Lockheed Martin F-35 Lightning II and form the basis for the propulsion system for the United States Air Force's sixth generation fighter program, the Next Generation Air Dominance (NGAD). The three-stream adaptive cycle design can direct air to the bypass third stream for increased fuel efficiency and cooling or to the core and fan streams for additional thrust and performance. The thrust class engine is expected to be significantly more powerful and efficient than existing low-bypass turbofans. Development The U.S. Air Force and U.S. Navy began pursuing the adaptive cycle engine concept in 2007 with the Adaptive Versatile Engine Technology (ADVENT) program, a part of the larger Versatile Affordable Advanced Turbine Engines (VAATE) program. While not involved with ADVENT, Pratt & Whitney was selected alongside General Electric for the Adaptive Engine Techno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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General Electric XA100
The General Electric XA100 is an American adaptive cycle engine demonstrator being developed by General Electric (GE) for the Lockheed Martin F-35 Lightning II and form the basis for the propulsion system for the United States Air Force's sixth generation fighter program, the Next Generation Air Dominance (NGAD). The three-stream adaptive cycle design can direct air to the bypass third stream for increased fuel efficiency and cooling or to the core and fan streams for additional thrust and performance. The thrust class engine is expected to be significantly more powerful and efficient than existing low-bypass turbofans. Development The U.S. Air Force and U.S. Navy began pursuing adaptive cycle engine in 2007 with the Adaptive Versatile Engine Technology (ADVENT) program, a part of the larger Versatile Affordable Advanced Turbine Engines (VAATE) program. This technology research program was then followed by the Adaptive Engine Technology Demonstrator (AETD) program in 2012, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |