2

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 that both engines of the aircraft won't spool up at the same rates, but what about the nozzles? Are the nozzles dependent on the engine power output (which would then answer this question), or are they independently controlled? If so, what causes them to close/open at different rates?

Here's an example from the Top Gun 2 trailer:

enter image description here

F16Falcon
  • 395
  • 3
  • 8

2 Answers2

2

The nozzle position is automatically adjusted according to the current engine state to maintain optimal exit flow conditions at the end of the nozzle.

The difference in nozzle actuation you are referring to is caused by a slight difference in activation time of the afterburner between the engines.

Please see the following Aviation Stack Exchange question and answer(s) for more information on the purpose of the nozzle: Why are adjustable area jet engine nozzles mostly limited to military use?

Jpe61
  • 28,574
  • 2
  • 75
  • 122
1

This photo show as the afterburner (left one ) literally just got ignite first one . So it is clearly to me the nozzles diameter is different ,one from another , (just for seconds)to ensure that the pressure of the gases exhaust is able to provide thrust. The left nozzle is opened more because the more mass of the burnt fuel left jet engine provide.To answer your question, the nozzles are not closed/open by the pilot lever or switch ,only the power setting thrust (for saving the fuel or lower the temperature in one )witch could be seen as difference in exhaust nozzles system )But sometimes , if engine is not running good the specific emergency settings will be able to do fixed pre-sett diameter to ensure the proper thrust for safety. reasons.https://theaviationist.com/2019/12/26/tu-22m3-backfire-engines-transition-from-idle-to-full-reheat-captured-in-stunning-detail/?fbclid=IwAR00KfC3zHPVln6wXGT6_5fyT7uWQGTta7RGe_3KwsDNemDZP21prTSen70

George Geo
  • 2,111
  • 11
  • 33