YAK 152 Strange Sound
YAK 152 Strange Sound
This is the YAK 152. It has a 6 ltre V12 diesel.
It makes a very odd sound, very much like 2 props out of synch.
Anyone got an idea why it makes such a strange sound?
It makes a very odd sound, very much like 2 props out of synch.
Anyone got an idea why it makes such a strange sound?
Avoid imitations
Join Date: Nov 2000
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Difficult to hear but likely to be resonance between the prop and the exhaust pulses.
Btw, what I noticed most was how much the nose dropped during some of the rolling manoeuvres. It seemed to wallow around.
Btw, what I noticed most was how much the nose dropped during some of the rolling manoeuvres. It seemed to wallow around.
Sounds to me simply like typical diesel engine clatter/knocking/growl/rumble. Which is due to diesels having a rather different cycle from gas/petrol engines - compression stroke compresses only air, to a very high proportion (19:1 in the RED A03), and then fuel is injected into the extremely hot compressed air near top-dead-center and ignites spontaneously (no spark).
Additionally, the RED A03 aircraft diesel has a reduction gear - the prop turns once per 1.88 engine revs. So yes, the engine and prop will only be exactly back in sync (same teeth on the gears meshing) once every 100 engine revs/53 prop revs.
Mix that with three prop blades and 12 cylinders, and no wonder there's a hop-skip-and-jump rhythm.
Additionally, the RED A03 aircraft diesel has a reduction gear - the prop turns once per 1.88 engine revs. So yes, the engine and prop will only be exactly back in sync (same teeth on the gears meshing) once every 100 engine revs/53 prop revs.
Mix that with three prop blades and 12 cylinders, and no wonder there's a hop-skip-and-jump rhythm.
I've spent a career watching/listening to different aircraft. I reckon Pattern_is_full is spot on.
You get a similar dissonance when an 8 cylinder (or a pair of fours) is driving a 3 blade prop. Not as exaggerated as the above example, though.
I quite like unusual sounding aircraft. Especially pistons.
You get a similar dissonance when an 8 cylinder (or a pair of fours) is driving a 3 blade prop. Not as exaggerated as the above example, though.
I quite like unusual sounding aircraft. Especially pistons.
This new engine is used by the Celera 500L as well.
