Plane on a treadmill

[Vegeta]

Nope, you still don't understand. You need the engines to create THRUST. The THRUST is what draws the air over the wings.

I told you earlier that even without engines it can take off if it has sufficient lift from for example just wind blowing or a massive fan. It doesn't need an engine runway or treadmill.

 

[Cray]

There is cancelling out of the thrust, the treadmill will exert force same as the engine will exert force , assuming the force is the same .
You will not achieve flight unless you have enough air flowing over the wings to achieve flight , solid or liquid ..

The treadmill acts of wheels which spin freely, how does that cancel out thrust that acts on the air?

 

[Alton Turner Blackwood]

*If* the plane remains stationary relative to the air then no lift is generated and the aircraft remains on the ground. However, the treadmill does not in any way counter the thrust of the engines which act to move the plane forward.

I think I'm going to agree with you. Thinking about it, the engines will act against the same surrounding column of air, and based on that the treadmill will have very little effect

 

[Rouge Pony]

if the axle is moving forward (relative to the ground, not the treadmill) at 5 m/s, the treadmill moves backward at 5 m/s. This is physically plausible. All it means is that the wheels will spin twice as fast as normal, but that won't stop the plane from taking off. Source google.

 

[Cray]

I think I'm going to agree with you. Thinking about it, the engines will act against the same surrounding column of air, and based on that the treadmill will have very little effect

Cool, try think of it like this, imagine holding a toy plane in place on a moving treadmill. The wheels are spinning at the same speed as the treadmill but there is no resultant force acting on the plane. If you choose to move the plane forward with your hand, the wheels will spin quicker than the movement of the treadmill. This is the same concept as the experiment, except that your hand is standing in as the thrust of the engines.

The speed of the treadmill in no way affects your ability to move the place forward across the surface of the treadmill because the treadmill has no ability to counter act the force applied by your hand.

 

[FNfal]

The treadmill acts of wheels which spin freely, how does that cancel out thrust that acts on the air?

One is exerting force forward and the other is exerting force backwards , if they are balanced they will cancel out .

 

[Sinbad]

One is exerting force forward and the other is exerting force backwards , if they are balanced they will cancel out .

How is the treadmill exerting a force? You keep saying this with no explanation of the HOW.

 

[LazyLion]

I told you earlier that even without engines it can take off if it has sufficient lift from for example just wind blowing or a massive fan. It doesn't need an engine runway or treadmill.

OK, but now you are introducing a new factor into the scenario.... Sufficient Wind Force coming from the front.
And the plane you are describing then is not an airplane, but a glider.
Let's rather stick with the original scenario rather than changing it at this point.

 

[themba990]

Short answer is no?

 

[Cray]

One is exerting force forward and the other is exerting force backwards , if they are balanced they will cancel out .

See post #225.

 

[Alton Turner Blackwood]

Cool, try think of it like this, imagine holding a toy plane in place on a moving treadmill. The wheels are spinning at the same speed as the treadmill but there is no resultant force acting on the plane. If you choose to move the plane forward with your hand, the wheels will spin quicker than the movement of the treadmill. This is the same concept as the experiment, except that your hand is standing in as the thrust of the engines.

The speed of the treadmill in no way affects your ability to move the place forward across the surface of the treadmill because the treadmill has no ability to counter act the force applied by your hand.

Gotcha!

 

[Alton Turner Blackwood]

Short answer is no?

We don't work with short answers here. Why no?

 

[Sinbad]

Short answer is no?

Wrong answer is no.

 

[Ho3n3r]

One is exerting force forward and the other is exerting force backwards , if they are balanced they will cancel out .

How is it cancelling out the thrust from the engines? It's only making the wheels spin faster.

 

[themba990]

The answer has already been given. The engines don't draw air over the wings, the forward motion of the plane does that. The engines cause the forward motion. If the plane can't move forward because it's on a treadmill then there will be no air over and under the wing and no lift.

 

[LazyLion]

Short answer is no?

Correct (and slightly longer) answer is yes.

 

[Sinbad]

The answer has already been given. The engines don't draw air over the wings, the forward motion of the plane does that. The engines cause the forward motion. If the plane can't move forward because it's on a treadmill then there will be no air over and under the wing and no lift.

How does the treadmill stop the plane moving?

 

[Cray]

The answer has already been given. The engines don't draw air over the wings, the forward motion of the plane does that. The engines cause the forward motion. If the plane can't move forward because it's on a treadmill then there will be no air over and under the wing and no lift.

The plane being on the treadmill is irrelevant, the thrust of the engines moves the place forward irrespective of what force is enacted on the wheels.

 

[themba990]

Oops, you guys are right. A car uses friction between tyres and the road to push itself forward. A plane 'pulls' on air to move itself forward so being on a treadmill will not stop the forward motion.

 

[Ho3n3r]

Oops, you guys are right. A car uses friction between tyres and the road to push itself forward. A plane 'pulls' on air to move itself forward so being on a treadmill will not stop the forward motion.

Don't worry, I had that epiphany too a few pages back.