本帖最后由 choi 于 10-30-2018 16:46 编辑
(c)
(i) Each Harrier (in service 1969- (UK retired it but US Marine Corps likes and retains it) ) has one (turbofan) engine, with four rotating nozzles (a pair of front nozzles and a pair of read nozzles).
(A) The engine is Rolls-Royce Pegasus.
Kevin Richardson, Vectored Thrust Jet Engines. MIT (2.972 is an undergraduate course; in the series "Reports on How Things Work")
http://web.mit.edu/2.972/www/rep ... _thrust_engine.html
View only the first pair of illustration: Left is top-down view (the front of engine/Harrier on the left; note blue-colored cold air through entry and combustion chamber red; the four parts jutting upward and downward are nozzles) and right is lateral view (showing nozzles tilting downward when taking off or landing).
(B) About the rotating nozzles again. See Harrier Hover Capability. Aerospaceweb.org, undated
www.aerospaceweb.org/question/planes/q0042.shtml
(view the top illustration only)
(C) Sheldon M Gallager, Coming: Jump Jets That Break the Sound Barrier. Popular Mechanics, June 1984, pages starting at 59
https://books.google.com/books?i ... egasus+rolls+royce+"front+nozzles"&source=bl&ots=4G8z4ZabXq&sig=M0QLg5lKXiNkp5cUQY_YP5gTW_Y&hl=en&sa=X&ved=2ahUKEwiDiMLsgq_eAhXET98KHTMjBjEQ6AEwDHoECAEQAQ#v=onepage&q=pegasus%20rolls%20royce%20"front%20nozzles"&f=false
(page 96: "(continued from page 62) * * * In the present Pegasus, fuel is burned only in the main combustion chamber leading to the two rear exhaust nozzles. The two front nozzles discharge compressed but unburned air supplied by the low-pressure fan. This provides sufficient thrust for vertical lift, but not enough for supersonic flight")
This page talked about "Plenum Chamber Burning" (PCB) to make Harrier supersonic (from subsonic) and compared PCB with afterburner. The project was canceled. So there is no need to read it.
(D) Harrier (BAe/McDonnel Douglas). School of Aeronautics and Astronautics, Purdue University, undated
https://engineering.purdue.edu/A ... ts/advanced/pegasus
("What gives the Harrier its capability is its thrust vectoring. Remarkably, there is no computer control of the nozzles. This means the Harrier has a fatally high learning curve, which has meant heavy losses over the years, but those who get through training are the best and most capable pilots in the world")
(ii) Yakovlev Yak-38 (in service 1976-1991l said to be a failure)
(A) https://en.wikipedia.org/wiki/VTOL
On the left of margin of this Wiki page is an illustration whose caption is "The Soviet Union's VTOL aircraft, the Yakovlev Yak-38 [where blue arrows signify cold air]." What one can not tell is the position (it appears two front nozzles on each side) -- and hence, the number -- of front nozzles.
(B) "The Yak-38 uses a main engine with two aft rotating nozzles and a set of small lift engines." from the Web.
(C) It turns out that the two front nozzles in Yak-38 is positioned midline. See the illustration (there is only one illustration) in
Yak-38 -- $3.95. Fiddlers Green (a site selling "paper models"), undated.
www.fiddlersgreen.net/models/aircraft/YAK-38.html
(D) Michael J Hirschberg, Soviet V/STOL Aircraft: The Struggle for a Shipborne Combat Capability. American Institute of Aeronautics and Astronautics, , at page 12
https://books.google.com/books?i ... &dq=The+Yak-38+"lift+nozzles"&source=bl&ots=HVJxUYcQPr&sig=QAy3dL9UZchPqYdfSBX_MCAH9Is&hl=en&sa=X&ved=2ahUKEwjkydO8ja_eAhVQt1MKHX-1CAAQ6AEwB3oECAkQAQ#v=onepage&q=The%20Yak-38%20"lift%20nozzles"&f=false
("III. Yakolev YAK-36M/YAK-38 FORGERS A. Overview[:] The Yak-38 Forger [NATO reporting name] was basically conventional design, utilizing a lift plus lift/cruise engine configuration (Fig. 10). Immediately behind the cocket were two nearly vertically oriented lift engines. The cruise engine was located along the fuselage centerline")
The three engines in Fig 10 are all topped with a black disc punctuated in the center with a white cone.
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发表于 10-30-2018 16:44:00
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