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A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically if it does not have a heavy payload) and land vertically (i.e. with no runway). The formal NATO definition (since 1991) is:

A Short Take-Off and Vertical Landing aircraft is a fixed-wing aircraft capable of clearing a 15 m (50 ft) obstacle within 450 m (1,500 ft) of commencing take-off run, and capable of landing vertically.

On aircraft carriers, non-catapult-assisted, fixed-wing short takeoffs are accomplished with the use of thrust vectoring, which may also be used in conjunction with a runway "ski-jump". Use of STOVL tends to allow aircraft to carry a larger payload as compared to during VTOL use, while still only requiring a short runway. The most famous examples are the Hawker Siddeley Harrier and the Sea Harrier. Although technically VTOL aircraft, they are operationally STOVL aircraft due to the extra weight carried at take-off for fuel and armaments. The same is true of the F-35B Lightning II, which demonstrated VTOL capability in test flights but is operationally STOVL.

History

Comparison of lift and thrust for various aircraft
In 1951, the Lockheed XFV and the Convair XFY Pogo tailsitters were both designed around the Allison YT40 turboprop engine driving contra-rotating propellers.

The British Hawker P.1127 took off vertically in 1960, and demonstrated conventional take-off in 1961. It was developed into the Hawker Siddeley Harrier which flew in 1967.

In 1962, Lockheed built the XV-4 Hummingbird for the U.S. Army. It sought to "augment" available thrust by injecting the engine exhaust into an ejector pump in the fuselage. First flying vertically in 1963, it suffered a fatal crash in 1964. It was converted into the XV-4B Hummingbird for the U.S. Air Force as a testbed for separate, vertically mounted lift engines, similar to those used in the Yak-38 Forger. That plane flew and later crashed in 1969. The Ryan XV-5 Vertifan, which was also built for the U.S. Army at the same time as the Hummingbird, experimented with gas-driven lift fans. That plane used fans in the nose and each wing, covered by doors which resembled half garbage can lids when raised. However, it crashed twice, and proved to generate a disappointing amount of lift, and was difficult to transition to horizontal flight.

Of dozens of VTOL and V/STOL designs tried from the 1950s to 1980s, only the subsonic Hawker Siddeley Harrier and Yak-38 Forger reached operational status, with the Forger being withdrawn after the fall of the Soviet Union.

Rockwell International built, and then abandoned, the Rockwell XFV-12 supersonic fighter which had an unusual wing which opened up like window blinds to create an ejector pump for vertical flight. It never generated enough lift to get off the ground despite developing 20,000 lbf of thrust. The French had a nominally Mach 2 Dassault Mirage IIIV fitted with no less than 8 lift engines that flew (and crashed), but did not have enough space for fuel or payload for combat missions. The German EWR VJ 101 used swiveling engines mounted on the wingtips with fuselage mounted lift engines, and the VJ 101C X1 reached supersonic flight (Mach 1.08) on 29 July 1964. The supersonic Hawker Siddeley P.1154, which competed with the Mirage IIIV for use in NATO, was cancelled even as the aircraft were being built.

NASA uses the abbreviation SSTOVL for Supersonic Short Take-Off / Vertical Landing, and as of 2012, the X-35B/F-35B are the only aircraft to conform with this combination within one flight.

The experimental Mach 1.7 Yakovlev Yak-141 did not find an operational customer, but similar rotating rear nozzle technology is used on the F-35B. The F-35B Lightning II entered service on July 31, 2015.

Larger STOVL designs were considered, the Armstrong Whitworth AW.681 cargo aircraft was under development when cancelled in 1965. The Dornier Do 31 got as far as three experimental aircraft before cancellation in 1970.


从装备史上看,STOVL战斗机的推进系统,有三个发动机机型,即英国鹞式的“飞马发动机”,苏联雅克-141的R-79+RD-41的发动机,以及美国的F135发动机,

1 鹞式 vs 飞马:发动机旋转排气喷管方案

  “飞马”由英国发动机传奇巨头罗尔斯-罗伊斯公司(以下简称RR)研制,安装在1957年英国霍克飞机公司和布里斯托尔航空发动机公司研制的P.1127 STOVL飞机上。1966年8月,装有第一台生产型飞马-6发动机的鹞式战机首飞。1975年飞马-11型开始研制,1979年9月投入使用。后续装备鹞式战机的成熟动力,是飞马11-21(Mk103),推重比7.01,和海军型飞马11-21(Mk104),推重比6.83


飞马属于推力转向涡扇发动机,推力换向方案为:旋转排气喷管。发动机采用双转子反向旋转消除陀螺力矩,改善悬停和过渡飞行时的稳定性。飞机垂直起降时,喷管由水平方向转向,机身前后有4个可旋转0°~98.5°的喷气口向下喷气,产生垂直升力。这样,发动机既提供升力又提供推力,在垂直/短距起落、悬停和过渡飞行时,操纵性和稳定性完全由喷气反作用操纵系统控制。

优点:该方案的最大特点是“升推一体”,即巡航推力和垂直升力均由一种发动机承担。结构简单、紧凑,推进系统死重小,短距起降性能好,甚至具有垂直起飞的能力。有兴趣的朋友可以看看施瓦辛格多年前的一部老片《真实的谎言》,其中有鹞式战机的经典起降场面。

  缺点:由于后喷管喷出的是热燃气,导致排气再吸入问题严重;因为垂直起降时悬停高度低,贫氧高温喷流从地面反弹,容易再次被发动机吸入,降低发动机效率,甚至造成喘振。垂直起飞非常费油。据说鹞式一个垂直起飞,1/4的内油就用完了,作战半径也就100公里左右

2.
与鹞式的发动机喷口转向方案不同,雅克系列采用的是巡航和升力分别采用不同发动机的方案。

  其中,巡航发动机为R-79推力矢量巡航涡扇发动机,最大加力推力约152千牛(15500公斤),不加力推力88.2千牛(8994公斤)。在靠近飞机重心处两个尾撑之间装圆形可转向喷口,使用寿命为1500个旋转循环。飞机短距起飞时,喷口向下偏转65°,打开至全加力状态,飞机滑跑5米可离地。喷口最大向下偏转角为95°,此时的升力推力约为发动机巡航推力的80%。该发动机压气机引气供给翼尖和机尾喷嘴时,其最大推力降到137.2千牛。


优点:该方案的最大特点是“升推分立”。巡航和升力发动机各司其职,保障了巡航发动机的效率和效能,使得雅克成为世界上首款超音速STOVL战机(鹞式为亚音速)。在试飞中,雅克-141甚至达到了1.4-1.7马赫的最大平飞速度。

  缺点:巡航和升力发动机的高温气流问题非常突出。飞机悬停时高温气流从发动机喷口喷出,到达地面后向外扩散。在机体下方形成低压区,产生suckdown效应,会把飞机牢牢“吸住”,这也是雅克-36首次试飞时没能起飞的原因。





              

                       

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