All Questions
Tagged with afterburner jet-engine
15 questions
0
votes
1
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137
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How do after-burners work on jet planes?
I've always wondered this after getting introduced to fighter jets, the sheer concept of being able to create a larger "exhaust" out of a fighter jet and cause it to speed up has always just ...
4
votes
2
answers
664
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Why afterburner fuel nozzles aren't creating a lot of drag during normal operation?
I cannot understand how afterburner fuel nozzles are not crating a lot of backpressure and allow engine to work when afterburner is not in use? They close almost 50% of the exhaust area. Is there any ...
- 3,862
7
votes
4
answers
6k
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How does a jet engine burn fuel when it is not on an afterburner?
I understand the idea behind afterburner as fuel is added to the exhaust to increase the mass and expansion of gasses to increase the thrust, and that explains (in very obvious way) how the fuel is ...
- 580
1
vote
1
answer
758
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How does afterburner efficiency vary with thrust?
Afterburners are much less efficient than turbine engines at converting fuel into thrust, so AFAIK no jet will engage afterburner unless it is already at full throttle on the turbine.
But what if an ...
- 2,284
2
votes
2
answers
1k
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Why do jet nozzles close at different rates?
After recently seeing the trailer for Top Gun 2, I was reminded of something that I always wondered about: why do the nozzles of some jet aircraft seem to close at different rates?
Sure, it's likely ...
- 395
6
votes
3
answers
1k
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Do afterburners use excessive amounts of fuel?
The purpose of an afterburner is to provide additional thrust, and it is obvious that more fuel is needed for that.
But that is to be expected independent of an afterburner. That more thrust needs ...
- 1,748
14
votes
2
answers
17k
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Why do Western fighters' afterburner glow is reddish orange while Eastern Bloc fighters' is blue?
Recalling what little physics I know, this could be explained by two factors:
The blue color is given by the characteristic EM radiation of C-H bond breaking, C- and H- radicals forming and ...
- 1,946
1
vote
1
answer
570
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Is jet fuel typically injected before or after the flame holder in an afterburner?
I don't have the best grasp on the intricacies of afterburners but I'd assume that if the engine has a flame holder then fuel would be injected before it in order to allow it to heat up to ...
2
votes
1
answer
540
views
Bright exhaust in afterburner vs no visible (bright) exhaust when not in afterburner?
When a jet engine has its afterburner engaged, a bunch of fuel is dumped into the back of the engine for additional thrust. This burning fuel causes the exhaust and inside the engine to glow brightly,...
- 1,789
6
votes
1
answer
1k
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What effect would a afterburner have on the compressor if the nozzle outlet is not increased?
In order to operate an afterburner, it is necessary to adapt the nozzle outlet area. As far as I understand it is necessary to open up the nozzle when the afterburner is increasing its temperature or ...
- 649
5
votes
1
answer
727
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How does the EPR reading behave in reverse, and in reheat modes?
Will an engine pressure ratio indicator (EPR) show the same at full mil thrust as with full reversed thrust?
What does the EPR indicate at afterburner active? Will it just show the same as for max mil ...
- 1,752
8
votes
3
answers
7k
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Is it possible to have an afterburner in a turbofan with bypass ratio greater than 1:1?
Is it possible to have an afterburner in a turbofan with a bypass ratio greater than 1:1? At 1.05:1, say, can it have an afterburner?
- 1,752
7
votes
1
answer
2k
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How does the Pratt & Whitney F119 achieve its features?
The Wikipedia article on the Pratt & Whitney F119 that powers the F-22 says the following:
The high pressure and low pressure turbines are single stage and counter-rotating, thus shortening ...
user14897
7
votes
1
answer
1k
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Will afterburner work at settings less than full dry thrust?
Dry thrust is normal jet engine power without using an afterburner. Max dry thrust is the engine's most powerful thrust level without afterburner.
But what if the engine is at half power, or even ...
- 17.9k
25
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6
answers
70k
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What is an afterburner and how long can a jet fly on afterburner?
I heard this word so many time in military documentary about jets, especially fighter jets, but I don't fully understand what it is or how it works. In a documentary from the Discovery Channel, all ...
- 1,862