RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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jesus christ Paul - remove your head from your anus - Lift is directly proportional to velocity squared ( velocity of advance)
if the velocity of advance required for take off is not met - guess what the plane wont take off
the velocity of advance is attributed to the ground speed required at take off, and the air through which the plane is moving - remebering that the air can be completely stationary.
I know how a jet engine works; I know how lift is generated!
you are the one who does not have a clue - you are so set in other peoples views that you are blinded by anyone who comes up with justifiable reasons against yoru argument!
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Paul_J
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Registered: 6th Jun 02
Location: London
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quote:
Originally posted by dave17
quote:
Originally posted by Paul_J
quote:
Originally posted by LiVe LeE
Providing the plane moves forward at a fast rate, it will get lift and take off.
IT can't take off straight away as you say, as it'll be too slow for enough lift.
say 180 mph FORWARD? So even with the treadmill stuck at 180 mph in reverse. the force pushing the plane FORWARD - will get the plane to 180 mph eventually.
What i think your missing Paul is the plane will not be travelling forward in a sense, it is stuck on the spot. Because whatever speed the engines are putting out, the converoy belt matches
no what I think your missing mate, is that the question does not say the conveyor belt is matching whatever the engine is putting out.
It says it matches the speed of the plane.
Speed of the plane with full thrust and brakes on can be 0 mph. The thrust out of the back can still be 26400 lb ft. The conveyor belt at this stage will be 0 not the equivalent of the engines power.
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Greg_M
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Registered: 2nd Sep 03
Location: Grantham, Lincolnshire
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AND THE PENNY HAS DROPPED
I finally understand. yes it would take off
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Hammer
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Registered: 11th Feb 04
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quote:
Originally posted by dave17
quote:
Originally posted by Paul_J
quote:
Originally posted by LiVe LeE
Providing the plane moves forward at a fast rate, it will get lift and take off.
IT can't take off straight away as you say, as it'll be too slow for enough lift.
say 180 mph FORWARD? So even with the treadmill stuck at 180 mph in reverse. the force pushing the plane FORWARD - will get the plane to 180 mph eventually.
What i think your missing Paul is the plane will not be travelling forward in a sense, it is stuck on the spot. Because whatever speed the engines are putting out, the converoy belt matches
i can see quite clearly why people are thinkin this as its the crux of the difference in opinion which is cropping up.
The people that think the plane stays stationary...can you tell me what would happen if the conveyor underneath the aircraft is moving at five times the speed of the aircraft itself? discounting tyre blowouts and other variables
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Greg_M
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Registered: 2nd Sep 03
Location: Grantham, Lincolnshire
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The treadmill this is irellivant as the plane moves in parallel to the ground. the wheels make no diference whatsoever.
[Edited on 24-05-2006 by Greg_M]
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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but the speed of the planes velocity of advance comes from the engines - these engines, when the plane is on the ground transmits force through chassis of the aircraft to the wheels - otherwise they wouldnt rotate nor would they be needed!
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John
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Registered: 30th Jun 03
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quote:
Originally posted by Greg_M
the wheels make no diference whatsoever.
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Paul_J
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Registered: 6th Jun 02
Location: London
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quote:
Originally posted by LiVe LeE
jesus christ Paul - remove your head from your anus - Lift is directly proportional to velocity squared ( velocity of advance)
if the velocity of advance required for take off is not met - guess what the plane wont take off
the velocity of advance is attributed to the ground speed required at take off, and the air through which the plane is moving - remebering that the air can be completely stationary.
I know how a jet engine works; I know how lift is generated!
you are the one who does not have a clue - you are so set in other peoples views that you are blinded by anyone who comes up with justifiable reasons against yoru argument!
jesus christ I give up with this shit. I'm not an idiot you fuck wit. I know the plane must be moving, what I'm explaining is in the scenerio brad has proposed the plane will be moving.
Everyone thinks the plane will be stationary as it is in a equalibreum state. but according to brads statement / question - the plane will not be in a equallibirum state - AS the conveyor isn't matching the SPEED OF THE ENGINE's it's matching the SPEED OF THE PLANE's movement.
Tbh I really can't be fucked anymore.
It's pointless, John, Steve and few others get it.
Svn, Dave etc are correct based on the logic of their thinking - Yup you are all correct if the plane is stationary on a treadmill then it won't have lift and won't take off. My point is based on the amount of thrust out of the back, it won't be stationary, but rather accelerating down the treadmill.
Can't be arsed anymore.
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Greg_M
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Registered: 2nd Sep 03
Location: Grantham, Lincolnshire
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the wheels are simply turned by friction of the surfac and a small amount of weight i would imagine.
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Jules S
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Registered: 24th Dec 03
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quote:
Originally posted by LiVe LeE
but the speed of the planes velocity of advance comes from the engines - these engines, when the plane is on the ground transmits force through chassis of the aircraft to the wheels - otherwise they wouldnt rotate nor would they be needed!
No they dont, that statement is about as inaccurate as it gets
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John
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Registered: 30th Jun 03
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They are only needed because there is no lift yet.
Say the plane had no wheels and was just lying on the treadmill.
After it overcame the force of the treadmill it would still take off.
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Paul_J
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Registered: 6th Jun 02
Location: London
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quote:
Originally posted by Greg_M
the wheels are simply turned by friction of the surfac and a small amount of weight i would imagine.
Awesome mate  nail on head
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dave17
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Registered: 3rd Sep 02
Location: Greater London
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Ok ok another way of looking at it then. Forget thrust/lb ft etc.
Lets focus on the wheels, as they are the part connecting the plane and the conveyor belt.
If the WHEELS are spinning at say, 100mph, then so is the conveyor belt. This is very much the same as you running at 10mph on a treadmill. If you MATCH th2 two speeds, they cancel eachother out, you will, in effect, be stationary.
IT doesnt matter HOW FAST you are running, you do not feel ANYMORE wind, as you are at a standstill.
Planes require wind/air to take off, there isnt ANY passing over/under the wings.
Now please tell me without these, how will it take off?
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John
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Registered: 30th Jun 03
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Dave thats right without the thrust.
Add the thrust to your situation then the plane takes off.
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Greg_M
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Registered: 2nd Sep 03
Location: Grantham, Lincolnshire
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no its no dave, forget about the wheel as i can see where you are comming from
Say the plane it sat on it under carrage. The belt would start to move and the plane would more back, but once the jet overcame inertia, it would move forward and take off.
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Jules S
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Registered: 24th Dec 03
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quote:
Originally posted by dave17
Ok ok another way of looking at it then. Forget thrust/lb ft etc.
Lets focus on the wheels, as they are the part connecting the plane and the conveyor belt.
If the WHEELS are spinning at say, 100mph, then so is the conveyor belt. This is very much the same as you running at 10mph on a treadmill. If you MATCH th2 two speeds, they cancel eachother out, you will, in effect, be stationary.
IT doesnt matter HOW FAST you are running, you do not feel ANYMORE wind, as you are at a standstill.
Planes require wind/air to take off, there isnt ANY passing over/under the wings.
Now please tell me without these, how will it take off?
So what you are saying is that if you are running on a treadmill and the treadmill matches your pace.....what happens if a force 100 gales startsblowing behind you?
You aint gonna get blown off the treadmill?
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Paul_J
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Registered: 6th Jun 02
Location: London
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quote:
Originally posted by dave17
Ok ok another way of looking at it then. Forget thrust/lb ft etc.
Lets focus on the wheels, as they are the part connecting the plane and the conveyor belt.
If the WHEELS are spinning at say, 100mph, then so is the conveyor belt. This is very much the same as you running at 10mph on a treadmill. If you MATCH th2 two speeds, they cancel eachother out, you will, in effect, be stationary.
IT doesnt matter HOW FAST you are running, you do not feel ANYMORE wind, as you are at a standstill.
Planes require wind/air to take off, there isnt ANY passing over/under the wings.
Now please tell me without these, how will it take off?
You can't forget the thrust coming out of the back. The difference between me running is the power is being put through the thing connected to the conveyor, same with a car on a rolling road. The difference here is there is something aside from the contact to the treadmill, that is the huge thrust out of the back.
As greg just realised. the conveyor merely matches the speed of the plane, not the forces involved. So the plane regardless of the speed of the conveyor will have more force than the conveyor and will move forward.
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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quote:
Originally posted by John
They are only needed because there is no lift yet.
Say the plane had no wheels and was just lying on the treadmill.
After it overcame the force of the treadmill it would still take off.
expand? and how?
and Jules Why is it inaccurate in any way? - what purpose do the wheels serve then?
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John
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Registered: 30th Jun 03
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If the plane had no wheels it would just need more power to overcome the friction of being on the ground before it was able to gain speed.
The wheels are just a handy way to overcome most of this friction and not damage the bottom of ur plane.
A plane on skis on water shows this.
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dave17
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Registered: 3rd Sep 02
Location: Greater London
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quote:
Originally posted by Jules S
quote:
Originally posted by dave17
Ok ok another way of looking at it then. Forget thrust/lb ft etc.
Lets focus on the wheels, as they are the part connecting the plane and the conveyor belt.
If the WHEELS are spinning at say, 100mph, then so is the conveyor belt. This is very much the same as you running at 10mph on a treadmill. If you MATCH th2 two speeds, they cancel eachother out, you will, in effect, be stationary.
IT doesnt matter HOW FAST you are running, you do not feel ANYMORE wind, as you are at a standstill.
Planes require wind/air to take off, there isnt ANY passing over/under the wings.
Now please tell me without these, how will it take off?
So what you are saying is that if you are running on a treadmill and the treadmill matches your pace.....what happens if a force 100 gales startsblowing behind you?
You aint gonna get blown off the treadmill?
No i wouldnt, because the conveyor belt would copensate for the rise in speed
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Jules S
Premium Member
Registered: 24th Dec 03
User status: Offline
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quote:
Originally posted by LiVe LeE
quote:
Originally posted by John
They are only needed because there is no lift yet.
Say the plane had no wheels and was just lying on the treadmill.
After it overcame the force of the treadmill it would still take off.
expand? and how?
and Jules Why is it inaccurate in any way? - what purpose do the wheels serve then?
they reduce the friction between the plane and the ground allowing the thrust to be more effective.
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Robin
Premium Member
Registered: 7th Jan 04
Location: Northants Drives: Clio 182 Cup
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I'm with Paul here
plane would move down the conveyor belt even if it was on skis
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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WIL PEOPLE THINK ABOUT WHAT THEY ARE SAYING
if your thoerys are correct what happens when you try and land on this moveing runway?
ACCORDING TO YOU WE WOULD STOP DEAD!!
you would carry on with momentum just like you would if you landed on solid ground.
FFS look at every article that google brings up, everyone that I have seen has concluded it would take off
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John
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Registered: 30th Jun 03
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quote:
Originally posted by dave17
quote:
Originally posted by Jules S
quote:
Originally posted by dave17
Ok ok another way of looking at it then. Forget thrust/lb ft etc.
Lets focus on the wheels, as they are the part connecting the plane and the conveyor belt.
If the WHEELS are spinning at say, 100mph, then so is the conveyor belt. This is very much the same as you running at 10mph on a treadmill. If you MATCH th2 two speeds, they cancel eachother out, you will, in effect, be stationary.
IT doesnt matter HOW FAST you are running, you do not feel ANYMORE wind, as you are at a standstill.
Planes require wind/air to take off, there isnt ANY passing over/under the wings.
Now please tell me without these, how will it take off?
So what you are saying is that if you are running on a treadmill and the treadmill matches your pace.....what happens if a force 100 gales startsblowing behind you?
You aint gonna get blown off the treadmill?
No i wouldnt, because the conveyor belt would copensate for the rise in speed
This has shown ur thinking is seriously flawed.
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Robin
Premium Member
Registered: 7th Jan 04
Location: Northants Drives: Clio 182 Cup
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Dave, you would be blown off the treadmill. the treadmill is irrelivant in your case
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