Plane on conveyer: Will it ever take off?
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From: Land of Cincinnati Chili
Originally Posted by esp1,Mar 29 2010, 11:17 AM
found this and I couldn't resist to revive this now defunct thread from 5 years ago . . . .it would not fly.
unless the wings are moving through the air there will be no lift created and the plane won't fly.
if the engines are drawing in air, compressing it, mixing it with jet fuel and burning the mixture, the result is a tremendous and continuous expansion of the gaseous mixture in the combustion and exhaust chambers of the engine. . . with the rapidly expanding gases having no where to go except out the back of the engine thrust is produced.
for the plane, this means that the the engine will want to go forward.
since it is attached to the plane, the plane also will want to go forward.
since the plane is attached to the wheels, they too will go forward.
the fact that the wheels are a conveyor moving in the opposite direction means that as the plane is "moving forward" the conveyor's moving backwards keeps the plane in the same spot.
which means the wings are not moving through the air.
which then means no lift is being generated
so the plane will not fly.
unless the wings are moving through the air there will be no lift created and the plane won't fly.
if the engines are drawing in air, compressing it, mixing it with jet fuel and burning the mixture, the result is a tremendous and continuous expansion of the gaseous mixture in the combustion and exhaust chambers of the engine. . . with the rapidly expanding gases having no where to go except out the back of the engine thrust is produced.
for the plane, this means that the the engine will want to go forward.
since it is attached to the plane, the plane also will want to go forward.
since the plane is attached to the wheels, they too will go forward.
the fact that the wheels are a conveyor moving in the opposite direction means that as the plane is "moving forward" the conveyor's moving backwards keeps the plane in the same spot.
which means the wings are not moving through the air.
which then means no lift is being generated
so the plane will not fly.
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From: Erock is da shizzle
Originally Posted by esp1,Mar 29 2010, 10:17 AM
found this and I couldn't resist to revive this now defunct thread from 5 years ago . . . .it would not fly.
unless the wings are moving through the air there will be no lift created and the plane won't fly.
if the engines are drawing in air, compressing it, mixing it with jet fuel and burning the mixture, the result is a tremendous and continuous expansion of the gaseous mixture in the combustion and exhaust chambers of the engine. . . with the rapidly expanding gases having no where to go except out the back of the engine thrust is produced.
for the plane, this means that the the engine will want to go forward.
since it is attached to the plane, the plane also will want to go forward.
since the plane is attached to the wheels, they too will go forward.
the fact that the wheels are a conveyor moving in the opposite direction means that as the plane is "moving forward" the conveyor's moving backwards keeps the plane in the same spot.
which means the wings are not moving through the air.
which then means no lift is being generated
so the plane will not fly.
unless the wings are moving through the air there will be no lift created and the plane won't fly.
if the engines are drawing in air, compressing it, mixing it with jet fuel and burning the mixture, the result is a tremendous and continuous expansion of the gaseous mixture in the combustion and exhaust chambers of the engine. . . with the rapidly expanding gases having no where to go except out the back of the engine thrust is produced.
for the plane, this means that the the engine will want to go forward.
since it is attached to the plane, the plane also will want to go forward.
since the plane is attached to the wheels, they too will go forward.
the fact that the wheels are a conveyor moving in the opposite direction means that as the plane is "moving forward" the conveyor's moving backwards keeps the plane in the same spot.
which means the wings are not moving through the air.
which then means no lift is being generated
so the plane will not fly.
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From: Queen City, NC
The premise is, if a plane doesn't move, can it take off. The answer is (without an outside force acting upon it) no, but people focus on the wheels spinning and start taking into account many variables that could effect whether or not a plane does or does not move, and then if it can take off or not.
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From: Erock is da shizzle
That's not the premise. A plane that can't move will not take off. A plane on an conveyor will.
The wheels are not what is making the plane move forward. If the conveyor matches the speed of the plane, the wheels will "freewheel" at twice the speed and the plane will still move forward.
I don't understand why a good number of people don't get that?
The wheels are not what is making the plane move forward. If the conveyor matches the speed of the plane, the wheels will "freewheel" at twice the speed and the plane will still move forward.
I don't understand why a good number of people don't get that?
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I was looking atTedow's earlier assessments, and I think he got one part wrong, unless I'm misunderstanding the setup. First, let me say that the plane WILL take off.
There are 2 possible scenarios for what happens with the wheels. If static friction is maintained, velocity of the wheels will exceed velocity of the conveyor belt. However, since the conveyor belt is always trying to equal the speed of the wheels, it will constantly speed up in an attempt to reach the speed of the wheels. It's kind of like the speed of the conveyor belt is chasing a carrot that's hung out in front of it on a stick tied to its back. It will continue to chase after it, but never reach it. Thus, the conveyor belt's speed and the wheel speed will blow up until take off.
If static friction is broken (that is, the force from the engine > friction), the wheel will simply drag along, and the conveyor belt will remain motionless (since the wheel isn't spinning). I'm not familiar with how peak thrust is reached on an airplane engine, so it might be that the wheel and conveyor speed blow up until a certain amount of thrust is reached, and then the wheel simply drags.
If the speeds get high enough during the initial static stage (before take off, obviously), when static friction is broken, the velocities involved might be high enough that kinetic friction could become velocity dependent, and I have no clue what could happen from there.
There are 2 possible scenarios for what happens with the wheels. If static friction is maintained, velocity of the wheels will exceed velocity of the conveyor belt. However, since the conveyor belt is always trying to equal the speed of the wheels, it will constantly speed up in an attempt to reach the speed of the wheels. It's kind of like the speed of the conveyor belt is chasing a carrot that's hung out in front of it on a stick tied to its back. It will continue to chase after it, but never reach it. Thus, the conveyor belt's speed and the wheel speed will blow up until take off.
If static friction is broken (that is, the force from the engine > friction), the wheel will simply drag along, and the conveyor belt will remain motionless (since the wheel isn't spinning). I'm not familiar with how peak thrust is reached on an airplane engine, so it might be that the wheel and conveyor speed blow up until a certain amount of thrust is reached, and then the wheel simply drags.
If the speeds get high enough during the initial static stage (before take off, obviously), when static friction is broken, the velocities involved might be high enough that kinetic friction could become velocity dependent, and I have no clue what could happen from there.
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Originally Posted by Saki GT,Mar 29 2010, 05:41 PM
The premise is, if a plane doesn't move, can it take off. The answer is (without an outside force acting upon it) no, but people focus on the wheels spinning and start taking into account many variables that could effect whether or not a plane does or does not move, and then if it can take off or not.
In that thread, I would say something like, "No".
In this thread, I would say that a treadmill will have such a small effect on an airplane, it will take off without a hitch.
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From: Little Rock AFB
They did this on myth busters
http://mythbustersresults.com/episode97.
BUSTED
http://www.youtube.com/v/0ul_5DtMLhc&hl=en_US&fs=1&
http://mythbustersresults.com/episode97.
BUSTED
http://www.youtube.com/v/0ul_5DtMLhc&hl=en_US&fs=1&
