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dyskinet1c t1_irqttx5 wrote

Turboprops are also limited to rotation speeds where the tips of the blades are below the speed of sound.

If the blades rotate above the speed of sound, the tips generate shock waves that reduces the efficiency significantly.

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barath_s t1_iryxaky wrote

> Turboprops are also limited to rotation speeds where the tips of the blades are below the speed of sound.

Laughs in Tu-95 and XF-84 Thunderscreech

> the outer 24–30 inches (61–76 cm) of the blades on the XF-84H's propeller traveled faster than the speed of sound even at idle thrust, producing a continuous visible sonic boom that radiated laterally from the propellers for hundreds of yards. The shock wave was actually powerful enough to knock a man down; an unfortunate crew chief who was inside a nearby C-47 was severely incapacitated during a 30-minute ground run. Coupled with the already considerable noise from the subsonic aspect of the propeller and the T40's dual turbine sections, the aircraft was notorious for inducing severe nausea and headaches among ground crews. In one report, a Republic engineer suffered a seizure after close range exposure to the shock waves emanating from a powered-up XF-84H

https://aviation.stackexchange.com/questions/22229/why-is-the-tu-95-so-efficient-despite-having-propellers-that-spin-faster-than-th

> The tips of the fan blades of a modern turbofan also move at supersonic speed, so the supersonic propellers on the Tu-95 do not create a direct disadvantage.

also

> The Tu-95 is one of the loudest military aircraft, particularly because the tips of the propeller blades move faster than the speed of sound.

https://aviation.stackexchange.com/questions/22316/why-do-turbofan-blade-tips-exceed-the-speed-of-sound-while-prop-tips-should-not

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Doggydog123579 t1_irzbsw1 wrote

WHAT DID YOU SAY? I COULDN'T HEAR YOU OVER THE SOUND OF MY EARS MELTING.

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barath_s t1_is0chgy wrote

SERVES YOU RIGHT FOR LOOKING AT THE ARK OF THE COVENANT BEING IN THE VICINITY OF THE THUNDERSCREECH

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