Mr Revhead[RL] Posted December 18, 2005 Report Posted December 18, 2005 stolen from various places. Imagine a plane is sat on the beginning of a massive conveyor belt/travelator type arrangement, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation. There is no wind. Can the plane take off? Explain why it can, or cannot, take off? also for the purpose of this question it is assumed all engineering possibilities eg the belt is possible. Quote
ancullen Posted December 19, 2005 Report Posted December 19, 2005 Surely it can't, because as it is not moving, it is not generating any wind resistance, therefore the correct air pressure cannot build up underneath the wings, therefore it cannot fly. Of course, you've probably got some tricky reason as to why it will fly, but I'll stick with my answer. Until Redwarf comes and explains exactly why it will/won't work Quote
James Posted December 19, 2005 Report Posted December 19, 2005 (edited) the convayer belt would have no effect on the aircraft, since unlike a corolla the aircraft does not reliy on the ground to move, there is no drive line attched to the wheels. The aircraft would use the air to push its self and not the conveyer and thus gain speed for take off. The only problem I can see with this setup is that the wheel berings will fail pematurly due to excess rotations cause by the conveyer belt manitaing the same speed I reread the question and I get the impression that the belt is designed to keep the wheels still. "The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation. " and the belt is moving in the same direction as the aircraft. any way an aircraft don't care how fast its wheels are spinning as long as its air speed is right it will take off :D Edited December 19, 2005 by James Quote
Jason Posted December 19, 2005 Report Posted December 19, 2005 (edited) I duno if I'm missing something, but when the convey goes in the opposite direction, its canceling out any movement therefore the toatal movement is 0, the wheels only provide free movement until the plane has enough speed to lift it self off the ground (created by wind passing over the wings, low pressure and so on) in all the planes ive seen, the jets do not create the wind, but just propel the plane forward. So all the energy thats been put in trying to move the plane foward (jets) has just been wasted since the convery is absorbing all its forward speed. Edited December 19, 2005 by Jason Quote
James Posted December 19, 2005 Report Posted December 19, 2005 (edited) I duno if I'm missing something, but when the convey goes in the opposite direction, its canceling out any movement therefore the toatal movement is 0, the wheels only provide free movement until the plane has enough speed to lift it self off the ground (created by wind passing over the wings, low pressure and so on) ? I was thinking along the same lines, any ways as I said before it would not matter which way the conver was moving, the plane does not reliey on the the speed of the belt, just the speed of the air Edited December 19, 2005 by James Quote
Jason Posted December 19, 2005 Report Posted December 19, 2005 (edited) Yes, but that air speed is created by the planes forward motion through air, made possible by freewheeling. >>> (Jet Propulsion) <<< (belt) No net speed = No air flowing over wings = no low pressure Edited December 19, 2005 by Jason Quote
Mr Revhead[RL] Posted December 19, 2005 Author Report Posted December 19, 2005 what causes a planes forward motion? have a think about that...... Quote
Jason Posted December 19, 2005 Report Posted December 19, 2005 (edited) the jets... well as far as i know any way Edited December 19, 2005 by Jason Quote
Mr Revhead[RL] Posted December 19, 2005 Author Report Posted December 19, 2005 yes, or a propeller, both use the same basic principle, and medium to create thrust.... keep thinking :D Quote
ancullen Posted December 19, 2005 Report Posted December 19, 2005 The jets or propellors, depending on the type of plane. I suppose if that's the case, then the wheels won't rotate as the conveyor belt will match the speed of the plane as it is dragged along by the propellors/jets. Therefore the wheels will have nothing to do with the speed of the plane, and the plane will attain the required speed and air pressures due to the propellors/jets. It will then take off. Quote
Jason Posted December 19, 2005 Report Posted December 19, 2005 (edited) The wheels are only turning because of the trust created by the engines, right? (going foward) They are not blowing on the wings. The way I see it, is that the wheels are only there to support the plane until it has enough speed to take off and can be supported by its own air speed? Then how can a plane take off if its net speed is 0? Edited December 19, 2005 by Jason Quote
TRAV-KE55 Posted December 19, 2005 Report Posted December 19, 2005 Thye plane still takes off becuase the planes forward thrust (motion) is done by the turbines or propelloers, the wheels have no drive so they just free wheel on the conveyor. Howevr the wheels probally explode due to excessive RPM therefor wounding the plane and skiding to a burning pile of shit at the end of the conveyor/runway and because the conveyor is travelling at the same speed in the oppisite direction it will then shoot the remaining fuesalage backwards down the runway beacause the conveyor cannot slow down fast enough, in turn the rapid change in direction will cause massive internall injurys to the passengers organs killing all on board. So i ask you this people, was this experiment worth killing hundreds of inocent civilian passengers for a ridle?? Its all bout the passengers people. PS: The concords wheels did fly apart wounding the plane, but it did still take off and fly 2 kms, so yes the plane will still take off. You questions have been answered. Trav Quote
Jason Posted December 19, 2005 Report Posted December 19, 2005 (edited) I still have one. A plane that is stationary. But with its jets at an infinite speed. Still take off?? There would be such minimal air passing over the wings? Unless there is some sort of inane vetri effect going on that I don’t know about? another eg. if you have a jet powered go kart. There is no driving force on the wheels, just the trust of the jet. You put it on this conveyer belt. Start it up, it dosnt move. If you stick you hand out of the side of the kart. Is there any wind? (Excluding the rush of air coming from the belt) Edited December 19, 2005 by Jason Quote
ancullen Posted December 19, 2005 Report Posted December 19, 2005 If it's jets are going wouldn't they be thrusting the plane forward and therefore creating airflow over the wings, hence making the plane fly? Quote
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