Questions tagged [afterburner]

Any questions asking about afterburners and how they work.

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7
votes
4answers
5k views

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 ...
3
votes
2answers
114 views

How does afterburning not affect upstream air in the engine?

I've read in many books that afterburners are designed not to affect the upstream engine components, so if there's a large amount of combustion going on after the addition of afterburner fuel, how ...
1
vote
1answer
391 views

Why are F-15s usually taking off with afterburners?

If there's no emergency, is it a big waste of money for military aircraft to take-off with afterburners? Why are they doing it, what are the advantages? Like here:
0
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0answers
57 views

Are variable area exhaust nozzles or variable area throats more impactful?

I was reading this NACA research paper where, while discussing an adjustable plug-type nozzle, they state: Although this nozzle did not have independently variable area throat and exit areas, as ...
1
vote
1answer
121 views

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 ...
0
votes
0answers
53 views

Hydrogen as fuel for jet engine or afterburner [duplicate]

Why is hydrogen not used as fuel for fighters? I understand that hydrogen engines are not yet developed but why is there no research going on in that file. Can't hydrogen be used in specially designed ...
0
votes
3answers
313 views

How can one achieve supersonic cruise capabilities without afterburners?

I have read that in order to have stealth capabilities of the F22, it was designed such that it could cruise at supersonic speeds without using afterburners, which increase RCS. How is this possible? ...
3
votes
2answers
163 views

How has afterburner design changed since its inception?

I came across a NACA summary paper on the past 5 years of afterburner development and started reading cause it seemed interesting. However, a couple of pages in I scrolled back up and realized that it ...
2
votes
2answers
370 views

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 ...
6
votes
3answers
746 views

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 ...
28
votes
2answers
12k views

Why would a fighter use the afterburner and air brakes at the same time?

I was looking for air brake pictures on different fighters, and then I saw a Tornado using afterburner and air brake at the same time! Air brake duty is to reduce speed, isn't it? So why would a ...
12
votes
1answer
2k views

What causes the sudden spool-up sound from an F-16 when enabling afterburner?

What causes the sudden spool-up sound from an F-16 when enabling afterburner? I've included a video to make it clear what sound I'm referring to: at 1:16, I assume ...
1
vote
1answer
357 views

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
1answer
248 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,...
2
votes
2answers
1k views

Is there an aircraft that can go supersonic at sea level without using afterburner?

Is there an aircraft that can go supersonic at sea level without using afterburner? Quick look through the "supercruise" capable aircraft might be helpful in narrowing down the possibilities, though I ...
2
votes
2answers
1k views

Are afterburners required to be engaged during catapult launch?

Is it required to engage afterburners during catapult launches from an aircraft carrier? This answer mentions that afterburners are used for night takeoffs as per regulations, but not required during ...
6
votes
1answer
701 views

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 ...
6
votes
2answers
1k views

Are warbirds allowed to use afterburners?

Suppose a civilian buys a military jet, for example an T-38. Would he be allowed to use afterburners?
4
votes
1answer
554 views

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 ...
7
votes
3answers
5k views

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?
14
votes
1answer
7k views

Why do military jets seem to always take off using the afterburner?

I was wondering. At different places I heard that civilian airplanes often (or even most of the time?) take off at less than 100% thrust. For example a question that tackles this is here: Is it ...
6
votes
1answer
1k views

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 ...
0
votes
1answer
311 views

How does an aircraft distribute fuel equally between powering the turbines on the engine and injecting it into the afterburner?

How does an aircraft distribute its fuel equally between powering the engine turbines and injecting it into the afterburner?
11
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2answers
3k views

What is missing from a non-afterburning engine to prohibit the use of afterburning?

What components are missing in a non-afterburning engine that an afterburning engine does, so that it can't use afterburning?
7
votes
1answer
888 views

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 ...
24
votes
6answers
54k views

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 ...