What Myth would you want to see busted?

Glaucus said:
No, the complete opposite.



Rpm limited makes sod all difference.
THE FORCES ARE NOT DIRECTLY LINKED.

Just like properly on a plane and a moving conveyor belt.
No direct link, so no cancelation of forces.
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Eh? You're no longer making sense! OK - example. We have a piston engined heli and let's say the crank directly drives the rotor blades and the engine is rev limited (mechanically/electrically - whatever) to 1000rpm. So looking down on the situation you have a heli sitting there stationary and the blades can do 1000rpm clockwise wrt the heli/ground. OK? Now you start spinning the heli anticlockwise on the turntable and you reach 1000rpm. Are you disagreeing that the rotor blades are now stationary wrt the ground? Are you saying the blades are still somehow doing 1000rpm clockwise wrt the ground even though the heli is now doing 1000rpm anticlockwise wrt the ground which would require the blades to be doing 2000rpm wrt the heli despite the 1000rpm limit on the heli engine?

Or are you accepting the blades would be stationary wrt the ground (and you'd just have this ridiculous spinning helicoptor body), but saying the blades would still be producing lift?
 
Very much disagreeing with you. Your logic fails as does you comprehension of physics.

How the hell in your world does a spinning helicopter body. Stop the pistons. It doesn't at all. The only difference is the force on the crankshaft bearings.
 
Glaucus said:
Very much disagreeing with you. Your logic fails as does you comprehension of physics.

How the hell in your world does a spinning helicopter body. Stop the pistons. It doesn't at all. The only difference is the force on the crankshaft bearings.
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What?? I'm afraid your comprehension of physics is failing. Why would the pistons be stopped? The spinning helicoptor body contains the spinning engine block. The crankshaft and rotor blades would be stationary wrt the ground, but the engine is still running at 1000rpm because the heli and engine block, etc are all spinning wrt the ground on the turntable.

I dont get it - you understand the speeds add because you were originally talking about the turboshaft engine main shaft running at double speed because the rotors run at double speed wrt to the heli if the blades are going full speed wrt the ground and the heli body is going same speed in reverse, so why can't you see that if you had a rev limited heli engine that could spin the blades at a max of 1000rpm wrt the heli and the heli was doing 1000rpm the other way wrt the ground on a turntable, that the blades would indeed be doing 0 rpm wrt the ground???
 
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Glaucus said:
Very much disagreeing with you. Your logic fails as does you comprehension of physics.

How the hell in your world does a spinning helicopter body. Stop the pistons. It doesn't at all. The only difference is the force on the crankshaft bearings.
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Have a much simpler example...

You have a record player turntable that spins records at 100rpm (clockwise as you look down on it). Say you place this record player on a bigger turntable that turns it 100rpm anticlockwise as you look down. What speed is the record spinning wrt the ground? Answer - it would be stationary wrt the ground. You seem to be saying the record would still be spinning at 100rpm wrt the ground? If so how did your record player switch to 200rpm?
 
I understand what you're saying Glaucus but have to disagree.

You agree that if the turntable rotates when the blades are stationary relative to the helicopter, the blades will be rotating relative to the ground, i.e. they are attached to a drive-shaft or something similar within the helicopter which keeps them in a fixed position regardless of bearings. If this was not true, the blades would remain stationary as the turntable and body of the helicopter rotate.

So when the helicopter starts turning the blades, the blades are still experiencing the rotational motion exerted by the turntable, and in the highly hypothetical situation where the helicopter wouldn't be destroyed by the ridiculous RPM it would need to spin at, these would cancel each other out. It isn't the same as the aeroplane experiment as they are fixed to a driveshaft and not allowed to "freewheel" as the wheels of the aeroplane would.
 
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Elixir said:
You agree that if the turntable rotates when the blades are stationary relative to the helicopter, the blades will be rotating relative to the ground, i.e. they are attached to a drive-shaft or something similar within the helicopter which keeps them in a fixed position regardless of bearings. If this was not true, the blades would remain stationary as the turntable and body of the helicopter rotate.

So when the helicopter starts turning the blades, the blades are still experiencing the rotational motion exerted by the turntable, and in the highly hypothetical situation where the helicopter wouldn't be destroyed by the ridiculous RPM it would need to spin at, these would cancel each other out. It isn't the same as the aeroplane experiment as they are fixed to a driveshaft and not allowed to "freewheel" as the wheels of the aeroplane would.
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No no and no.

The blades will not be stationery in relation the air rats body. Wtf. You have one spinning in one direction, the other spinning in the opposite direction. The combined speed with be twice either one.
No there is nothing keeping them in a fixed position.
No the blades are not experiancig the rotation speed from the turntable. Just like the plane is not experiancig the force from a conveyor belt, only the wheels and bearings on the plane experience that. Ame with helicopter the rotating body and bearings experience the force, not the blades.
They would not cancel each other out at all, it is that simple.
 
Besides, they were too effeminate

Dimple said:
Why did their arch enemies Russia admit to it then?
Go on - mythbuster that one.

What did the 1000s and 1000s of Ham Radio enthusiasts follow to the Moon?
Go on - mythbuster that one.
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Man didn't land on the moon, it's an American lie. They did fake the moon landing there.
watch

http://www.youtube.com/watch?v=P6MOnehCOUw

You expect people to believe you without sources?
 
glacius, im quite happy to admit i dont know a lot about helicopters, but im saying you are wrong if the following assumptions are made:
- the engine of the helicopter cannot rotate relative to the body of the helicopter
- the engine of the helicopter is directly linked to the blades through a gearbox of some sort
- the maximum speed that the blades can go is limited by the maximum RPM of the engine
- no damage will occur to the helicopter in this experiment

if this were true, and you spun the helicopter around at the maximum RPM that the engine could spin the blades in the opposite direction, then held the blades still, the engine would be doing its maximum RPM in the forwards direction. this is because the blades are rotating relative to the helicopter at their maximum speed. since the helicopter is rotating at the blades and engines maximum speed in the opposite direction the engine will be exactly countering this action

now, what i would like you to do is tell me, in the real world, where my assumptions fall down (excluding the helicopter falling apart, or anything that stops the engine from working like centrifugal force on the fuel).
is it that the blades are not limited by the maximum speed of the engine, but by air resistance, and the engine will happily spin more than twice as fast given no blades to push through the air.

i know full well that no one would be stupid enough to make a helicopter where the engine has no direct link to the helicopter because then you'd waste a load of the power just spinning the entire engine round and round uselessly in the opposite direction to the blades
 
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