[gif] too much front brake and leaves cycle before impact

[goof2]

The thrust of a jet or propeller doesn't make a plane fly, the forward motion that thrust imparts pushes the wings through the air creating lift which leads to flight. Assuming it is possible for a treadmill to move fast enough to create enough friction in the tires, wheel bearings, etc. that the thrust couldn't overcome to create forward movement then the airplane would not take off. It would have to be extremely fast since that would take a hell of a lot of speed to generate that much friction, there couldn't be enough wind to create lift without forward motion, and of course it couldn't be a VTOL aircraft.

['73 H1 Triple]

Originally Posted by goof2

The thrust of a jet or propeller doesn't make a plane fly, the forward motion that thrust imparts pushes the wings through the air creating lift which leads to flight. Assuming it is possible for a treadmill to move fast enough to create enough friction in the tires, wheel bearings, etc. that the thrust couldn't overcome to create forward movement then the airplane would not take off. It would have to be extremely fast since that would take a hell of a lot of speed to generate that much friction, there couldn't be enough wind to create lift without forward motion, and of course it couldn't be a VTOL aircraft.

I think if the treadmill was moving that fast, just the speed of the tread itself would generate enough wind currents for the plane to lift off of the tread itself.




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So did the biker do a head plant into the car or not?

[Turbo Ghost]

Alright, let's try to get this cleared-up.
If I put a treadmill in front of a wall and told you to run on it, would you say "NO! I'll hit the wall!"?? Of course not! Your body would be STATIONARY while running on the treadmill! THIS is the whole basis of the treadmill/plane concept. The propeller DOES NOT make the plane fly! Airflow over the wings is what creates lift. The propeller only moves the plane forward so that air moves over the wings which provides the lift to get the plane airborne. If the plane isn't moving (which it is not because it is on a treadmill!) it has no lift!
If you had a glider which is simply an airplane without a motor and you put a giant fan in front of it that could provide enough airflow for lift, it would lift off the ground BUT, it wouldn't move forward! It has no prop therefore it has no forward motion.
So, here's the bottom-line! If a plane is on a treadmill, it is stationary. A stationary plane does not fly! UNLESS, you perform this test during a tornado or hurricane in which the windspeed surrounding the plane is sufficient to provide lift.

['73 H1 Triple]

Originally Posted by Turbo Ghost

Alright, let's try to get this cleared-up.
.

but, but, I had so much fun with this subject before

['73 H1 Triple]

Originally Posted by Turbo Ghost

Alright, let's try to get this cleared-up.
If I put a treadmill in front of a wall and told you to run on it, would you say "NO! I'll hit the wall!"?? Of course not! Your body would be STATIONARY while running on the treadmill! THIS is the whole basis of the treadmill/plane concept. The propeller DOES NOT make the plane fly! Airflow over the wings is what creates lift. The propeller only moves the plane forward so that air moves over the wings which provides the lift to get the plane airborne. If the plane isn't moving (which it is not because it is on a treadmill!) it has no lift!
If you had a glider which is simply an airplane without a motor and you put a giant fan in front of it that could provide enough airflow for lift, it would lift off the ground BUT, it wouldn't move forward! It has no prop therefore it has no forward motion.
So, here's the bottom-line! If a plane is on a treadmill, it is stationary. A stationary plane does not fly! UNLESS, you perform this test during a tornado or hurricane in which the windspeed surrounding the plane is sufficient to provide lift.

1) The spinning prop generates forward motion and the wings provide the lift as the air moves over them.
Do you agree?

2) Lets pick a forward speed of 50 mph that generates enough lift for the plane to "have the opportunity to become airborne".
Agree with statement 2?

3) The big treadmill has a belt speed of 60 mph. If they plane had it's brakes applied, it would be moving backwards at 60 mph.

3A) Since the brakes are not applied, the wheel are moving "backwards" at 60 mph. ( let's pretend somebody is at each wingtip holding the plane in place, only to prevent backwards movement ) The pilot applied throttle and the plane moves forward. Once he gets to 50 mph , the wheels are moving the equivilent 110 mph and the plane becomes airborne.



edit, added the bold wording for clarity

[Turbo Ghost]

Originally Posted by '73 H1 Triple

1) The spinning prop generates forward motion and the wings provide the lift as the air moves over them.
Do you agree?

2) Lets pick a forward speed of 50 mph that generates enough lift for the plane to "have the opportunity to become airborne".
Agree with statement 2?

3) The big treadmill has a belt speed of 60 mph. If they plane had it's brakes applied, it would be moving backwards at 60 mph.

3A) Since the brakes are not applied, the wheel are moving "backwards" at 60 mph. ( let's pretend somebody is at each wingtip holding the plane in place) The pilot applied throttle and the plane moves forward. Once he gets to 50 mph , the wheels are moving the equivilent 110 mph and the plane becomes airborne.

A spinning prop generates forward motion. HOWEVER, the entire purpose of a treadmill is allow work without forward motion.
In 3A, you contradict yourself. If the wings are being held, the plane is not moving and therefore will not lift. The speed of the wheels is irrelevant.
The whole problem with this entire scenario is the fact the wheels are not driven. Since the prop acts upon air and not the treadmill itself, there is no way to make it work.
As I said before, the purpose of a treadmill is to allow you to remain motionless relative to your surroundings. A motionless plane will not lift.

[Turbo Ghost]

Originally Posted by '73 H1 Triple

but, but, I had so much fun with this subject before

Physics theories always create great opportunities for Devil's Advocates! You can entertain yourself for days with this stuff!

[Homeslice]

Originally Posted by Turbo Ghost

That's just it! The plane isn't moving! There IS no airspeed! The only things moving are the treadmill and the wheels which are only rotating. I don't quite think you understand why planes fly. The motor and propeller and wheels have nothing to do with it!

Actually I have full understanding of what causes lift. Airspeed over a wing surface. That's all. What a treadmill is or isn't doing doesn't mean jack shit, as long as the airspeed is sufficient.

However, once a plane takes off, it WILL need engines to STAY aloft. That's all I was saying.

[Homeslice]

Originally Posted by Turbo Ghost

If you had a glider which is simply an airplane without a motor and you put a giant fan in front of it that could provide enough airflow for lift, it would lift off the ground BUT, it wouldn't move forward! It has no prop therefore it has no forward motion.

Not only that, but it would get pushed backwards as soon as it lifts off. And then sink back down to earth.

['73 H1 Triple]

Originally Posted by Turbo Ghost

A spinning prop generates forward motion. HOWEVER, the entire purpose of a treadmill is allow work without forward motion.
In 3A, you contradict yourself. If the wings are being held, the plane is not moving and therefore will not lift. The speed of the wheels is irrelevant.
The whole problem with this entire scenario is the fact the wheels are not driven. Since the prop acts upon air and not the treadmill itself, there is no way to make it work.
As I said before, the purpose of a treadmill is to allow you to remain motionless relative to your surroundings. A motionless plane will not lift.

I didn't word it perfectly ( my error/mistake ) but what I inferred was the wings were being held only to prevent backwards movement. ( correction/edit added )

Therefore, the the spinning prop would generate the forward momentum needed to achieve takeoff after the required lift was generated.

All the treadmill would do is spin the wheels. The only "extra" would be addition bearing RPM from the wheels being on the treadmill.

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Maybe your looking at this from a different prespective than I am. See the "Myth Busters" episode on this? That's what I "see". A normal plane and a movable "runway" under the wheels. The prop generates enough forward speed to achieve takeoff regardless of the wheel speed.

Originally Posted by Turbo Ghost

Physics theories always create great opportunities for Devil's Advocates! You can entertain yourself for days with this stuff!