New answers tagged noise
2
That noise is almost exclusive to turbo fan engines. If the air is right, turbo shaft engines can do it.
On sudden and high power changes the big fan on the front is spinning at a different speed than the motor compressor. Since the front fan is also the first couple of stages of the engine compressor, the air doesn't move cleanly between the two when ...
1
A fairly obvious point that seems to have been missed in the other answers: how fast can you cycle the winch? A busy airport might have planes departing every couple of minutes. To get to cruise altitude, your winch has to reel in a considerable length of cable. This then has to fall to the ground after the aircraft releases it, which takes a minute or ...
10
To explain if the afterburner makes the engine louder, you must understand what the afterburner does. In the afterburner, the exhaust gases are re-heated by injecting fuel in the afterburner duct. The left oxygen is used to burn the fuel, which results in an increased exhaust gas flow. Note that the engine itself will not spool up faster: this is done by ...
1
From an energy standpoint, the engine produces heat, thrust, and less significantly, sound. Ignore the afterburner for a second and just consider throttling up, whether a jet or your car. The engine gets louder. That's not a law of physics, that's just what happens. There's no theoretical reason why the extra waste energy can't go 101% into heat, and -1% ...
28
This PDF indicates an increase by ~10 dB for an F-8K in afterburner versus the same aircraft in 100% dry thrust.
This PDF indicates smaller increases:
+5 dB for an F-15
+4 dB for F-22 and F-35
-4
If you are asking if the engine is louder, no it is not. The afterburner and the diversion of the exhaust is what makes it louder. Just like in a car motor running straight pipe to gain horsepower. You can take the same motor and put an exhaust system on it and it will give that motor a different tone.
14
I would say definitely yes, because of all the extra energy added to the exhaust flow and it's obvious to anyone who attended enough military airshows. Watch an F-16 depart with reheat on, then reduce thrust to military power (max thrust with reheat off) on the climb out, and it almost sounds like the engine flamed out.
The flow out the nozzle may be ...
24
It has been around 20 years since I've been on a carrier deck, but I recall that it wasn't as dramatic of an increase as you might think. It may have gotten a little bit louder, but what I remember more is that the tone changed. The sound was more "full" when the afterburner was engaged. I realize this is a rather subjective answer.
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