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Gas Turbine Engine Thrust
The familiar study of jet aircraft treats jet thrust with a "black box" description which only looks at what goes into the jet engine, air and fuel, and what comes out, exhaust gas and an unbalanced force. This force, called thrust, is the sum of the momentum difference between entry and exit and any unbalanced pressure force between entry and exit, as explained in "Thrust calculation". As an example, an early turbojet, the Bristol Olympus Mk. 101, had a momentum thrust of 9300 lb. and a pressure thrust of 1800 lb. giving a total of 11,100 lb. Looking inside the "black box" shows that the thrust results from all the unbalanced momentum and pressure forces created within the engine itself. These forces, some forwards and some rearwards, are across all the internal parts, both stationary and rotating, such as ducts, compressors, etc., which are in the primary gas flow which flows through the engine from front to rear. The algebraic sum of all these forces is delivered to the airframe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Aircraft
A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by jet engines. Whereas the engines in propeller-powered aircraft generally achieve their maximum efficiency at much lower speeds and altitudes, jet engines achieve maximum efficiency at speeds close to or even well above the speed of sound. Jet aircraft generally cruise most efficiently at about Mach 0.8 () and at altitudes around or more. The idea of the jet engine was not new, but the technical problems involved could not begin to be solved until the 1930s. Frank Whittle, an English inventor and RAF officer, began development of a viable jet engine in 1928, and Hans von Ohain in Germany began work independently in the early 1930s. In August 1939 the turbojet powered Heinkel He 178, the world's first jet aircraft, made its first flight. A wide range of different types of jet aircraft exist, both for civilian and military purposes. History After the first instance of powered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dassault Mirage
Mirage is a name given to several types of jet aircraft designed by the French company Dassault Aviation (formerly Avions Marcel Dassault), some of which were produced in different variants. Most were supersonic fighters with delta wings. The most successful was the Mirage III in its many variants and derivatives, which were widely produced and modified both by Dassault and by other companies. Some variants were given other names, while some otherwise unrelated types were given the Mirage name. Early prototypes * MD550 Mystère Delta, the original Dassault experimental delta jet, which provided the baseline for the main Mirage series. Two were built, later renamed Mirage I and II respectively: ** Mirage I, being the MD550-01 renamed. ** Mirage II, being the MD550-02 renamed. Mirage III/5/50 series The most successful line of Mirages were a family of supersonic delta-winged fighters, all sharing the same basic airframe but differing in powerplant, equipment and minor details. Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressor Map
A compressor map is a chart which shows the performance of a turbomachinery compressor. This type of compressor is used in gas turbine engines, for supercharging reciprocating engines and for industrial processes, where it is known as a dynamic compressor. A map is created from compressor rig test results or predicted by a special computer program. Alternatively the map of a similar compressor can be suitably scaled. This article is an overview of compressor maps and their different applications and also has detailed explanations of maps for a fan and intermediate and high-pressure compressors from a three-shaft aero-engine as specific examples. Compressor maps are an integral part of predicting the performance of gas turbine and turbocharged engines, both at design and off-design conditions. They also serve a critical purpose in selecting the correct compressors for industrial processes. Fans and turbines also have operating maps, although the latter are significantly different in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lockheed SR-71
The Lockheed SR-71 "Blackbird" is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation. It was operated by the United States Air Force (USAF) and NASA. The SR-71 was developed as a black project from the Lockheed A-12 reconnaissance aircraft during the 1960s by Lockheed's Skunk Works division. American aerospace engineer Clarence "Kelly" Johnson was responsible for many of the aircraft's innovative concepts. The shape of the SR-71 was based on that of the A-12, which was one of the first aircraft to be designed with a reduced radar cross-section. Initially, a bomber variant of the A-12 was requested by Curtis LeMay, before the program was focused solely on reconnaissance. Mission equipment for the reconnaissance role included signals intelligence sensors, side looking airborne radar, and a camera; the SR-71 was both longer and heavier than the A-12, allowing it to hold mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mikoyan MiG-31
The Mikoyan MiG-31 (russian: link=no, Микоян МиГ-31; NATO reporting name: Foxhound) is a supersonic interceptor aircraft that was developed for use by the Soviet Air Forces. The aircraft was designed by the Mikoyan design bureau as a replacement for the earlier MiG-25 "Foxbat"; the MiG-31 is based on and shares design elements with the MiG-25. The MiG-31 is among the fastest combat jets in the world. It continues to be operated by the Russian Air Force and the Kazakh Air Force following the end of the Cold War and the collapse of the Soviet Union in 1991. The Russian Defence Ministry expects the MiG-31 to remain in service until 2030 or beyond; that was confirmed in 2020 when an announcement was made to extend the service lifetime from 2,500 to 3,500 hours on the existing airframes. Development Origins The single-seat MiG-25 could achieve high speed, altitude and rate of climb; however, it lacked maneuverability at interception speeds and was difficult to fly at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dassault Rafale
The Dassault Rafale (, literally meaning "gust of wind", and "burst of fire" in a more military sense) is a French Twinjet, twin-engine, Canard (aeronautics), canard delta wing, Multirole combat aircraft, multirole fighter aircraft designed and built by Dassault Aviation. Equipped with a wide range of weapons, the Rafale is intended to perform air supremacy, Air interdiction, interdiction, aerial reconnaissance, close air support, ground support, in-depth strike, anti-ship warfare, anti-ship strike and Nuclear warfare, nuclear deterrence missions. The Rafale is referred to as an "omnirole" aircraft by Dassault. In the late 1970s, the French Air Force and French Navy were seeking to replace and consolidate their existing fleets of aircraft. In order to reduce development costs and boost prospective sales, France entered into an arrangement with the UK, Germany, Italy and Spain to produce an agile multi-purpose "Future European Fighter Aircraft" (which would become the Eurofighter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonnell Douglas F-15 Eagle
The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather tactical fighter aircraft designed by McDonnell Douglas (now part of Boeing). Following reviews of proposals, the United States Air Force selected McDonnell Douglas's design in 1969 to meet the service's need for a dedicated air superiority fighter. The Eagle first flew in July 1972, and entered service in 1976. It is among the most successful modern fighters, with over 100 victories and no losses in aerial combat, with the majority of the kills by the Israeli Air Force.Spick 2000, p. 127. The Eagle has been exported to Israel, Japan, and Saudi Arabia. The F-15 was originally envisioned as a pure air-superiority aircraft. Its design included a secondary ground-attack capability that was largely unused. The aircraft design proved flexible enough that an improved all-weather strike derivative, the F-15E Strike Eagle, was later developed, entered service in 1989 and has been exported to several nations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonnell Douglas F-4 Phantom II
The McDonnell Douglas F-4 Phantom II is an American tandem two-seat, twin-engine, all-weather, long-range supersonic jet interceptor and fighter-bomber originally developed by McDonnell Aircraft for the United States Navy.Swanborough and Bowers 1976, p. 301. Proving highly adaptable, it entered service with the Navy in 1961 before it was adopted by the United States Marine Corps and the United States Air Force, and by the mid-1960s it had become a major part of their air arms. Phantom production ran from 1958 to 1981 with a total of 5,195 aircraft built, making it the most produced American supersonic military aircraft in history, and cementing its position as an iconic combat aircraft of the Cold War."F-4 Phantoms Phabulous 40th" Boeing. Retrieved : 27 November 2012. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afterburning
An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and combat. The afterburning process injects additional fuel into a combustor in the jet pipe behind (''i.e.'', "after") the turbine, "reheating" the exhaust gas. Afterburning significantly increases thrust as an alternative to using a bigger engine with its attendant weight penalty, but at the cost of increased fuel consumption (decreased fuel efficiency) which limits its use to short periods. This aircraft application of "reheat" contrasts with the meaning and implementation of "reheat" applicable to gas turbines driving electrical generators and which reduces fuel consumption. Jet engines are referred to as operating ''wet'' when afterburning and ''dry'' when not. An engine producing maximum thrust wet is at ''maximum power,'' while an engine pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric CJ805
The General Electric CJ805 is a jet engine which was developed by GE Aviation in the late 1950s. It was a civilian version of the J79 and differed only in detail. It was developed in two versions. The basic CJ805-3 was a turbojet and powered the Convair 880, while CJ805-23 (military designation TF35), a turbofan derivative, powered the Convair 990 airliners. Design and development Impetus Turbojet engines consist of a compressor at the front, a burner area, and then a turbine that powers the compressor. In order to reach worthwhile compression ratios, compressors consist of multiple "stages", each further compressing the air leaving the previous one. One common problem with early jet engines was the phenomenon of "surging" or compressor stall. Stalls could occur when the approaching airflow was not in-line with the aircraft inlet to the compressor or when the throttle was advanced too quickly. When engines had to be designed with pressure ratios greater than about 5, to meet d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SEPR 841
The SEPR 84 is a family of liquid-propellant rocket engines used as boosters for the Dassault Mirage III mixed-power high-altitude interceptor aircraft of the 1960s. The engine was one of several similar developed by SEPR ( Société d'Etudes pour la Propulsion par Réaction). SEPR 841 SEPR's auxiliary rocket engines were based on the hypergolic fuel chemistry of nitric acid oxidiser and TX2 (tri-ethylamine xylidine) fuel. Unusually, the turbopump for the engine was mechanically driven from outside. A mechanical drive shaft from the accessory drive of the main turbojet provided the needed at 5,070 rpm, provided that the engine was running at full speed. As the propellants are hypergolic, the engine can be ignited repeatedly simply by engaging the clutch drive to the pump. Bulk production of the engines was carried out by Hispano-Suiza. SEPR 844 For simplicity of fuel supply, the TX2 fuel of the SEPR 841 was replaced with standard Jet TR-0 / JP-4 / JP-5 (kerosene) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Engine
A jet engine is a type of reaction engine discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include Rocket engine, rocket, Pump-jet, water jet, and hybrid propulsion, the term typically refers to an internal combustion airbreathing jet engine such as a turbojet, turbofan, ramjet, or pulse jet engine, pulse jet. In general, jet engines are internal combustion engines. Airbreathing jet engines typically feature a Axial compressor, rotating air compressor powered by a turbine, with the leftover power providing thrust through the propelling nozzle—this process is known as the Brayton cycle, Brayton thermodynamic cycle. Jet aircraft use such engines for long-distance travel. Early jet aircraft used turbojet engines that were relatively inefficient for subsonic flight. Most modern subsonic jet aircraft use more complex High-bypass turbofan, high-bypass turbofan engines. They give higher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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