Plane on a treadmill...

[MadduckUK]

this is a plane, not a car, where thrust is exerted through friction with the ground.

i believe your theory is flawed sir.

[99Flake]

i believe your theory is flawed sir.

Not quite since due to the speed and forces involved the Thrust SSC had to be designed to stay ON the ground. Any aircraft will take off on anything so long as it has enough air pressure over the wings and enough force to overcome the friction on the wheels.

[charleski]

Has to have a hamster to be a proper jetcar!

[kalniel]

Scary thing is that they will probably put a 747 on a giant treadmill just out of stupidities sake and try it. Would make great TV though!!

Nah they'll put hammond in a jet propelled... oh wait, that's already been done

Anyway answer to the OP is that it depends who built the plane - if it was most people then the wheels will have only been engineered with something like 20% tolerance over roll out speed. As the plane accelerates down the treadmill the treadmill will continuously speed up trying (vainly) to keep the plane in place. If the plane takes off really quickly then fine, but otherwise the wheel speed will rapidly exceed tolerances and the wheels will fall off. The plane now has a lot of friction with the 'ground' and it's a battle to see if the thrust will ever overcome it

[MadduckUK]

ok then hippies, bluebird says your wrong. about something or other

[99Flake]

I think the simlplist answer to this is the following:

Assuming that the treadmill is sensitive enough to react to the physical turning of the wheels, the treadmill will spin. This will have the effect of not allowing the aircraft to have any forward motion since thrust would be cancelled out by friction.

However we all know that that is very difficult, a whole treadmill will not react to three small wheels with small contact areas due to lack of friction. Therefore aircraft will overcome those forces and the equal reaction to the thrust will be flight.

Problem with this question is we have a theoretical (unbuildable) treadmill that does SEEM to be capable of keeping up with the rotational speed of the wheels. Thus aircraft will stay stationary and not have any speed and therefore air over wings for flight.

EDIT: I have just said all that but am now completely unsure in my head. I am going to try and build a mini model to see the outcome.

[kalniel]

About the effect of hitting a seemingly small variation in surface causing a seperation of boundary layers and causing it to flip?

[kalniel]

Problem with this question is we have a theoretical (unbuildable) treadmill that does SEEM to be capable of keeping up with the rotational speed of the wheels. Thus aircraft will stay stationary and not have any speed and therefore air over wings for flight.

Then why not have an equally unbuildable frictionless wheel mechanism

[99Flake]

Then why not have an equally unbuildable frictionless wheel mechanism

True, I don't profess to know the answer, all I know is that I should have an idea as aero design technology is what I did at uni! Damned confusing!

[BlindMelon7]

Why do you guys think the wheels would move in the first place? The friction would move them a bit but it would... wait... I just realized that the treadmill is going in the same direction as the wheels are turning . Ignore my theory.

[Butcher]

Wheels don't matter - hence seaplanes.