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Topic closed

2006-12-26 11:43:35
spray_and_pray
Member
+52|6710|Perth. Western Australia
Look kiddies aircraft fly using bernoulli's theory "where speed is greatest pressure is least" since wings are in an aerofoil shape bottom is flat top is curved the top is also longer then the bottom lets say the top is 3M the bottom is 2M but the air needs to get around at the same time on both sides. To cover the top as quick as the bottom the air has to pass over fast. Because its passing over fast on the top then the bottom the pressure pushing the wing down is releive and the pressure pushing the wing up is constant. So the wing is swept up and it takes the aircraft with it. The aircraft is not sucked up if you read this on websites it is wrong it is pushed up. Without speed you cant produce lift unless you got a 400MPH headwind and an aircraft which can fly backwards.

Aircraft also use Newtons 3rd law but this can only be put into effect once it is in the air. Newtons 3rd law is "For every action there is an equal and opposite reaction" and it has to do with the angles that the wings are on this is also referred to as "ski effect" I wont explain it here because its got nothing to do with the question but you can google it.

Those are the 2 ways a wing works only 1 of them counts for this question if the aircraft isn't going forward its wings arent producing lift it is not going to get off the ground. Aircraft are also powered by their engines while on the ground which means the forward movement does not come from the wheels powering themselves and moving forward like is the movement in a car. It will not take off full stop red f*cking dot. If anyone continues to argue I hope you have read up on Bernoulli's theorem and Newtons 3rd law or your argument is pretty much useless. Try me.
2006-12-26 11:43:39
viper313
One Shot, One Kill
+53|6861|Minnesota

nonexistentusmc wrote:

I just came from the gym, got on the treadmill and guess what, if there is no thrust from the engine, (considering that this "treadmill" is an actual runway) the jet does move backwards and will go to the end. Theres a subway station in NYC where theres one of those conveyor belt type walkways. Put on your rollerblades and act like a plane with your engines off and youll just go with the flow(whichever way the walkway is going). You need equilibrium in the middle. If you're going to give me theres no friction in the wheels bs or the no engine in the wheels bs then youre still going to be wrong. SOMETHING has to hold the object(in this case airplane) in place for the wheels to rotate. We should go ask Newton about this. And I'm sure he'll side with the "no, the plane is not going to take off, and the plane will move with the belt if the engine is off" answer.

This is a crazy thread.
Thanks, someone who gets it.  +1 to you
2006-12-26 11:43:48
King_County_Downy
shitfaced
+2,791|6816|Seattle

viper313 wrote:

What's the most posts posted in one day?  I think we might break the record.   And I said that if the planes engines were off the plane would fall off the back.
https://www.uploadfile.info/uploads/88fcbd28d5.gif
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
2006-12-26 11:45:21
Valium500mg.
Member
+3|6560
Krouser is right, all that will be affected by the treadmill is the tires which are free to rotate at what ever speed they need to, It's a physics thing. The engines make thrust thus pushing the plane forward the wheels are merely there to reduce drag during takeoff, when the plane moves forward at 10 MPH the treadmill will do 10 MPH in the opposite direction making the wheels go 20 MPH or your on a moving walk way with Rollerblades on and your Buddie is on the regular carpet walkway pulling you with a rope you will go forward like a water skier, they amount of force needed from your Buddie will be affected by the condition of your blades.
Chew on that.
Best gift this year a book elegant universe by Brian Greene

Last edited by Valium500mg. (2006-12-26 11:55:43)

2006-12-26 11:46:21
viper313
One Shot, One Kill
+53|6861|Minnesota
http://www.uploadfile.info/uploads/88fcbd28d5.gif
Thats just sick!
2006-12-26 11:47:54
heggs
Spamalamadingdong
+581|6607|New York
it doesn't matter a damn thing how fast the plane is moving on this treadmill. if there is no airflow, there is no lift. if you put this same plane on this same treadmill with airflow at the treadmill's speed, NOW we would have lift being generated.

and if the treadmill did theoretically compesate for friction, the plane would still not take off. the speed of the plane doesn't matter so much as it's airspeed.


you are basically dealing with a fluid dynamics problem here. the fluid (air) is not moving around the wings of the plane. if you don't have any fluid flow, you don't have lift.


ATG: concerning your last post:

Would not the thrust of the engines eventually render the plane in effect weightless?
no. the thrust force would equal the drag force and render the plane stationary. this is a basic physics problem with forces in different directions.

Allowing it to fly?
no. it has nothing to do with position, but how much air flows over the wings' surface. the engines on a plane merely push or pull the plane along so that the wing can do the work of providing lift.



read spray_and_pray's post. he explains what is going on well. i can second that as i've taken classes in aerodynamics and fluid mechanics.

Last edited by heggs (2006-12-26 11:57:23)

Remember Me As A Time Of Day
2006-12-26 11:48:30
King_County_Downy
shitfaced
+2,791|6816|Seattle

You make my head assplode viper

If you were female, I'd call you a cunt. Can't Understand Normal Thinking
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
2006-12-26 11:52:25
viper313
One Shot, One Kill
+53|6861|Minnesota

King_County_Downy wrote:

You make my head assplode viper

If you were female, I'd call you a cunt. Can't Understand Normal Thinking
Sorry, I cant help it if i'm smarter than you.

Last edited by viper313 (2006-12-26 11:53:02)

2006-12-26 11:56:56
tupla_s
.
+455|6811|Finland
Yes, 'cos it's a F-35 and it could go up

And even if it wasn't: However fast the treadmill turns, the wheels will just turn faster until there's sufficient speed to take off because thrust is produced by something other than the wheels

Last edited by tupla_s (2006-12-26 12:01:14)

2006-12-26 12:01:55
Valium500mg.
Member
+3|6560
you are still missing the point that the wheels don't drive the plane, they are rollers nothing more the engines will still push the plane to take off speed. Think about the wheels when a plane lands, they are not spinning until they touch the ground
2006-12-26 12:09:41
King_County_Downy
shitfaced
+2,791|6816|Seattle

Valium500mg. wrote:

you are still missing the point that the wheels don't drive the plane, they are rollers nothing more the engines will still push the plane to take off speed. Think about the wheels when a plane lands, they are not spinning until they touch the ground
it's useless, they can't understand it.
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
2006-12-26 12:09:52
GunSlinger OIF II
Banned.
+1,860|6863
i dont know about a plane but im sure a helicopter will see wheels up
2006-12-26 12:11:18
Wolfren
Member
+6|6883|USA

RandomSchl wrote:

d3athwi5h4 wrote:

No, the plane being stationary wouldn't create any lift
oops sorry thats only if the wheels propelled it. Yea it would take off but with the belt always matching the speed of the wheels and the plane still moving  forward at a more than 100 mph I bet that belt would be flying too.

Last edited by Wolfren (2006-12-26 12:13:57)

2006-12-26 12:11:36
heggs
Spamalamadingdong
+581|6607|New York

tupla_s wrote:

Yes, 'cos it's a F-35 and it could go up

And even if it wasn't: However fast the treadmill turns, the wheels will just turn faster until there's sufficient speed to take off because thrust is produced by something other than the wheels
read my post please.
Remember Me As A Time Of Day
2006-12-26 12:14:42
GunSlinger OIF II
Banned.
+1,860|6863

King_County_Downy wrote:

Valium500mg. wrote:

you are still missing the point that the wheels don't drive the plane, they are rollers nothing more the engines will still push the plane to take off speed. Think about the wheels when a plane lands, they are not spinning until they touch the ground
it's useless, they can't understand it.
you sold me.
2006-12-26 12:16:26
ATG
Banned
+5,233|6748|Global Command

heggs wrote:

it doesn't matter a damn thing how fast the plane is moving on this treadmill. if there is no airflow, there is no lift. if you put this same plane on this same treadmill with airflow at the treadmill's speed, NOW we would have lift being generated.

and if the treadmill did theoretically compesate for friction, the plane would still not take off. the speed of the plane doesn't matter so much as it's airspeed.


you are basically dealing with a fluid dynamics problem here. the fluid (air) is not moving around the wings of the plane. if you don't have any fluid flow, you don't have lift.


ATG: concerning your last post:

Would not the thrust of the engines eventually render the plane in effect weightless?
no. the thrust force would equal the drag force and render the plane stationary. this is a basic physics problem with forces in different directions.

Allowing it to fly?
no. it has nothing to do with position, but how much air flows over the wings' surface. the engines on a plane merely push or pull the plane along so that the wing can do the work of providing lift.



read spray_and_pray's post. he explains what is going on well. i can second that as i've taken classes in aerodynamics and fluid mechanics.
What we need is a brainiac to post some funky equations looking tingies.
2006-12-26 12:19:52
heggs
Spamalamadingdong
+581|6607|New York
if you haven't taken any engineering or physics courses you won't understand anything i post anyway. it's easier to explain the theory behind it.
Remember Me As A Time Of Day
2006-12-26 12:20:59
viper313
One Shot, One Kill
+53|6861|Minnesota
Why doesn't someone make this into a poll.  I think it would be interesting to see the numbers!
2006-12-26 12:29:33
Jasp
Bongabilla
+171|6881|The Outer Circle
A diagram to see if people understand,

https://www.qfom.com.au/images/how_wings.gif

To put it simple, there is NO airflow over the wing on a treadmill, the wheels are there only for movement on the ground. For the aircraft to takeoff the aircraft would have to equal the opposite force, and then over that speed to its Vr speed.

Eg: Treadmill @ 200mph opposite speed,

If the aircraft had a takeoff speed of say 200mph (no less),

Then for it to takeoff the aircraft would have to have a measured ground speed of 400mph, to counteract the movement of the 'ground'

Now I hope that makes some sense as I am half soaked
https://static.bf2s.com/files/user/11882/holteendersig2.jpghttps://forums.bf2s.com/img/avatars/11508.gif
2006-12-26 12:32:45
ATG
Banned
+5,233|6748|Global Command
Is that your sister in your sig?
Can I date her?
2006-12-26 12:41:25
Jasp
Bongabilla
+171|6881|The Outer Circle
If it were i'd be locked up!

Last edited by TPM-J45P3R- (2006-12-26 12:41:42)

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2006-12-26 12:46:25
acidkiller187
Member
+123|6849

TPM-J45P3R- wrote:

If it were i'd be locked up!
Sick bastard .... But Alla's, so would I
2006-12-26 12:47:23
Kung Jew
That one mod
+331|6964|Houston, TX
1. apply forehead to desk

2. lather, rinse, repeat till mild concussion occurs.

3. Thank ATG for smoking out a brain fart that has snarled the attention of so many bf2s members.

KJ
2006-12-26 12:48:46
ATG
Banned
+5,233|6748|Global Command
My pleasure.   
2006-12-26 13:02:55
Krauser98
Extra Green Please!
+53|7049|USA! USA! USA!
OMG.  If I could start flaming people and not get banned, I think I would.  Instead, I would like to thank all the people who are supporting my answer. 

All you people who say something about friction, you're crazy.  Have you ever taken a physics class?  Wheels create what is known as static friction.  Basically (I'm not a physicist here, so I could use some help here) it means that the wheels have a constant grip on the ground and when a car's axle turns the wheel that grip pushes the car forward.  When a car "peels out" it has overcome the static friction and the wheels are just sliding on the ground.  In this scenario we are talking about a plane though.  The friction between the wheels in the ground remains the same as it would regardless of the speed of the ground or treadmill.  What the wheels do for the plane is negate the friction between the ground and the plane so that it can move forward when the engines provide thrust.  The thrust does not come from the wheels moving.  There is no axle tied between the jet and the wheels, nor are there any cables which make them spin.  If you turned an airplane upside down and fire up the engines, the wheels probably wouldn't spin very much.

Up north I believe it is very common for a plane to take off on ice, they just have skis on them.  This would be similar to your treadmill question in that the wheels wouldn't be useful (if you still believe the wheels are what makes a plane move forward then they would just slide on the ice.)  Also, sea planes take off in water that is moving the other direction all the time...  If you still believe a plane can not take off on a treadmill I'll get my professor / pilot dad to write a short paper about it and I'll post it on the internets (but it will be really boring).

Edit:  I posted this w/o realizing there was a second page.  I'm not changing anything though.  For all of you people who claim the treadmills speed will keep the plane stationary, will you please explain to me how it is affecting the air traveling through a jet or prop?  Because those are pushing off the air (not the ground), which makes the plane move forward, which makes the air move around the wings (not because the jet / prop pushes the air past the wings, but because the planes forward motion makes the air move past the wings), which creates lift, which makes the plane fly.

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