Hurricane engine torque

[Buzpilot]

Originally Posted by Viper2000

3000 engine rpm * 0.477 = 1431 prop rpm

Come on, it really isn't that hard is it?

I didn't know it was the engine that is locked at 3000rpm, always seemed logic to me that it was the prop that used constant speed.

[Viper2000]

They are connected together with a fixed ratio gear box so it amounts to the same thing...

[Buzpilot]

Originally Posted by Viper2000

They are connected together with a fixed ratio gear box so it amounts to the same thing...

Yes, I see now, a 3000rpm propella ,de Havilland 9 ft 8 in (2.97 m) diameter would run at about 466m/s, a bit faster than sound
And at 1431, it's only about 222m/s.

[Viper2000]

However, once the aeroplane is flying, the tip speed is

((static tip speed)^2+TAS^2)^0.5

So at say 150 m/s TAS your static 222 m/s tip speed becomes more like 268 m/s.

At 20,000 feet this is a Mach number of about 0.85.

[kimosabi]

This thread is what happens when engineers and theorists sober up.

[Viper2000]

Originally Posted by kimosabi

This thread is what happens when engineers and theorists sober up.

So you're saying that this thread is a massive coffee binge, followed by feverish attempts to catch up on all the work that should have been done during the party?

[kimosabi]

Ya.