Airplane + Conveyor Belt
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- shilohous0
well, it is supposed to be a kickss conveyer that can match the speed right?
- Nairn0
this is going no further than the innumerate ID threads..
- ribit0
"No! Planes aren't built to provide that extra thrust! There's no way it's as tiny as you think it is. It's probably several tonnes worth... A fighter jet maybe, but not an average plane."
Do you have any references for this 'several tonnes' amount? We're only talking increased wheel drag here...remember airspeed for takeoff is not increased.
- joyride0
wheels are freespinning right, then you will get a little friction. but the thrust will easily overcome that. the 2 forces are independent, thrust pulls the plane forward no matter how fast the conveyor is spinning
- ribit0
"well, it is supposed to be a kickss conveyer that can match the speed right?"
we've already established that the conveyer is matching the aircrafts speed...the question is how much of a drag component does that apply to the plane through its wheels.
- jakeyj0
so ribit - you are saying the plane has airspeed?
if i'm running on a treadmill my hair doesn't blow in the wind...
- Nairn0
no, what ribit's envisaging is a state where thrust and belt are expending so much energy, that the focus (the wheels) turn into an electromagnetic plasma, creating a frictionless interface between plane and belt, at which point the infinitely-thrusting plane will be able to overcome the belt's limitations and begin accelerating to air take-off speed.
i think.
I concede.
but I'm still right. :)
- joyride0
it would if you sat on a turbine engine with wheels on it... =)
If you put a plane on a conveyor belt with a string attached. Pull the plane forward... what happens to the wheels as the conveyor tries to go faster. they go faster. The only way to negate the pull of the string forward is to have something pulling it in the opposite direction. Freewheeling wheels do not achieve this.
- determinedmoth0
Do you have any references for this 'several tonnes' amount? We're only talking increased wheel drag here...remember airspeed for takeoff is not increased.
ribit
(Feb 14 06, 07:34)No, but it's obvious. If I parked a plane on your head, you'd die under several tonnes of pressure. The friction that causes between plane and ground, and I am guessing, is HUGE, and not insignificant "wheel drag". It's very significant.
- ribit0
"so ribit - you are saying the plane has airspeed?
if i'm running on a treadmill my hair doesn't blow in the wind..."
Thats because you arent moving relative to the air in the room. You are running forward at the same speed as the belt moves backwards. The plane has abit more power than you do, and it doesnt push against the ground (or against the air to any great extent for that matter).
- ribit0
"No, but it's obvious. If I parked a plane on your head, you'd die under several tonnes of pressure. The friction that causes between plane and ground, and I am guessing, is HUGE, and not insignificant "wheel drag". It's very significant."
Yes I would die under the weight of the plane.
But planes seem to deal very nicely every day with this weight (due to big wings and big engines) , and a bit more drag on the wheels due to a doubling of their rotation speed isnt going to be such a big deal in percentage terms..
- determinedmoth0
That's where we differ then ;)
- ribit0
another point to consider:
Air flow induced by the moving belt may slightly increase the planes airspeed, which may shorten the takeoff run (a bit)
- ribit0
The Pilot's Lounge #94: It's The Medium, Manfred:
http://www.avweb.com/news/column…