Linked Questions

8 votes
1 answer
7k views

How does a supersonic jet engine differ from a subsonic jet engine? [duplicate]

All jet engines have the same method of air flowing into the engine, which is compressed and ignited. What can engine designers do to make an engine design create more thrust? For example, what is ...
Ethan's user avatar
  • 9,349
3 votes
1 answer
576 views

How does a wing mounted jet engine on a supersonic airplane prevent the interference in the flow due to Shock? [duplicate]

Wing mounted jet engines face the free stream at Mach number 1 or above, and they work perfectly for Mach numbers below 1 as well, even though the free stream characteristics change a lot after Mach 1....
Victor Juliet's user avatar
2 votes
1 answer
923 views

Is it possible to control the inlet Mach no. of the engine during flight? [duplicate]

While calculating the off design conditions of the engine, we need to know the off design characteristics, such as inlet additive drag. In the book Mechanics of Flight, by Warren F. Phillips, its ...
Manish's user avatar
  • 569
0 votes
2 answers
236 views

Why is a reciprocating engine air intake a reverse bell shape? [duplicate]

Why would this inlet for the induction system get wider as the air approaches the filter? What net effect does this have on intake pressure, and how would an inlet that starts wide and then narrows ...
Ryan Mortensen's user avatar
112 votes
4 answers
42k views

Why is the maximum speed of current fighter aircraft lower than those from the 1960's and 1970's?

While reading about the characteristics of the newest fighter aircraft, I observed that their maximum speed is lower than of the aircraft in the same roles half a century ago. For example, the iconic ...
vsz's user avatar
  • 2,001
50 votes
12 answers
39k views

Why is the nose of the Mig-21 shaped so differently compared to other fighter aircraft?

If you look at this picture below, you will notice that the nose portion of the Mig-21 has a unique conical shape which is completely different from the nose of the F-16. (Source) (Source) So what ...
CSinha's user avatar
  • 1,321
67 votes
5 answers
43k views

What determines the maximum altitude a plane can reach?

What factors determine the maximum altitude for a plane? Is it limited by wing design, engine thrust, and so on? Is there a formula by which one can calculate the maximum altitude a plane can reach?
Vido's user avatar
  • 761
39 votes
4 answers
19k views

Why do gases in the combustion chamber only flow one direction to the gas turbine in a jet engine?

As far as I know from the working principle of jets engines, compressed air in the combustion chamber (or combustion canister) is mixed with fuel. The ignited mixture expands backwards to turn the ...
albin's user avatar
  • 677
26 votes
4 answers
8k views

If jets carried pure O2 to use for combustion, would they be more efficient?

Air is around 21% Oxygen. The bulk of air is non-flammable Nitrogen. Wouldn't surrounding the jet fuel with only O2 create more efficient and clean combustion?
Jon Rausch's user avatar
29 votes
2 answers
7k views

Are the fastest moving pieces of a jet engine supersonic?

A jet engine is composed of fast moving pieces. Those pieces are moving into an airmass different form the ambient airmass the aircraft is flying into. The turbine pieces are spinning quite fast, ...
Manu H's user avatar
  • 16.5k
20 votes
2 answers
26k views

Why do military turbofan engines use a low bypass ratio?

I know that the most civilian engines use a high bypass ratio which is good for fuel economy and noise reduction. What prevents military engines from using the same technology instead of opting for ...
Anarach's user avatar
  • 393
12 votes
4 answers
4k views

Can I simply use multiple turbojet engines to fly supersonic?

the jet engine FJ33 produced by Williams International produces around 6 kN thrust (maximum, at sea level). Imagine: to fly supersonic, I need for my aircraft 9 kN of continious thrust. I am wondering ...
Lucas's user avatar
  • 179
10 votes
5 answers
7k views

Why do jet engines have a maximum speed?

What's the scientific background behind a jet engine's top speed? Jet engines increase efficiency at higher airflow rates, so why does the efficiency stop increasing at some point?
thebiggay's user avatar
  • 109
20 votes
2 answers
12k views

How is supercruise achieved?

Wikipedia article tells that supercruise is a condition when an aircraft can achieve velocities above Mach one without using the highly inefficient afterburners. But still, there are not a lot of ...
Victor Juliet's user avatar
11 votes
5 answers
10k views

Can a convergent nozzle be used for a supersonic jet engine?

Can a supersonic fighter incorporate a convergent nozzle or does it always have to be a convergent-divergent nozzle?
abdulhaseeb's user avatar

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