Plane on a Conveyer Belt

[qtipextra 5,000+ posts]

What the hell are you trying to explain then?

That the plane wont take off.

At this point, we are going over the same thing over and over, and it doesnt get us anywhere. That is why I have chosen not to try and prove my point any longer. But let it be known that I still stand behind my opinion that it will not take off.

 

[bikinpunk 10+ year member]

*assuming the wheels don't catch fire*

Jet propulsion is constant (in most cases). Lift (as I stated in pretty good detail) is due to velocity of the air at the wing. If the jet is providing constant thrust, and the wheels are moving, and the conveyor belt is moving you have friction at the wheels. However, the friction is not enough to overcome the constant thrust. And since lift is relative to airspeed (not landspeed) you have lift.

The riddle itself is kooky. I had to think about this for a bit and then I realized that if the belt is moving the plane is moving and vice versa; otherwise the entire "system" would be static and then you have no lift. As long as the jet engines are firing and get you up to the velocity you need to attain flight, I don't see any reason you won't have lift.

 

[UndercoverPunk 5,000+ posts]

Because my simple brain just plain can't handle the concept. What now?

 

[bikinpunk 10+ year member]

I'm not saying I'm dead right. It's just my logic and it seems to make sense.

I'll pose this question to my Aerodynamics & Propulsion profs tomorrow during my design course. I'd be interested to haer their thoughts. There's no definate answer, imo... too many variables. You really have to assume that the question is very straightforward, and from what I gather here, it's not.

 

[UndercoverPunk 5,000+ posts]

/sarcasm?

 

[bikinpunk 10+ year member]

/sarcasm?

You gotta use the //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif guy.

 

[squeak9798 5,000+ posts]

I have no idea what this setup is that you guys are talking about. I'm not going to read 8 pages of arguing to figure out wtf this setup is. But, since alot of people don't seem to understand the simple reasons why a plane will fly to begin with...
Lift is caused by pressure differential over & under a plane's wing. Bernoulli's equation. The pressure is inversely proportional to local velocity. Ideal Gas Law. As velocity of the air under the wing increases, pressure decreases... part1. part2... shape of an airfoil (wing) determines velocity under & over the wing. So, a wing with a flat bottom has higher velocity under the wing than it does over the wing (assuming it's not symmetrical, which it shouldn't be unless you don't want to fly) so you now have higher pressure under the wing than you do over the wing. High pressure below=bouyancy. Bouyance=lift.

So, it doesn't matter how the air moves under the wing, all that matters is that it does. So, essentially lift is due to velocity at the wing. With the proper velocity & airfoil shape you can get the plane off the ground.

So, now say you've put a plane on wheels and push it. You have velocity at the wings. This is the same situation as if you put a plane in a shopping cart, or on a conveyor. You get lift because you get velocity.

Edit: I'm dyslexic.

Actually, Bernoulli's principle is not the reason a plane can fly. It might play a small role, but it is not the primary cause and is quite insignificant in comparison to the actual reason.

The reason a plane flies is essentially due to how it diverts the airflow. It diverts the airflow downward. Newton' Third Law; For every action there is an equal and opposite reaction. The action is the diversion of airflow downward. The reaction is lift. When air is directed downward, the object moves upward.

Though I'm no aeronautical engineer.....from what I understand Bernoulli is essentially no where in the calculations relating to wing design.

 

[IamDeMan 5,000+ posts]

I am not going to attempt to expain my reasoning behind my opinion. It is apperant that none of you see what I am actually trying to get accross. This may be due to the fact that I am not explaining my point very good. Either way, we will find out on the 30th.

It's a good thing we don't get your point, because then we'd all be retards.

 

[IamDeMan 5,000+ posts]

That the plane wont take off.
At this point, we are going over the same thing over and over, and it doesnt get us anywhere. That is why I have chosen not to try and prove my point any longer. But let it be known that I still stand behind my opinion that it will not take off.

I will continue to "imply" that your opinion matches the intelligence of a 3 year old.

 

[qtipextra 5,000+ posts]

OK. I actually thought long and hard about this last night, in bed.

After running many different senarios through my head, I am finally able to realize that the plane speed in the air can be matched to the speed of the belt and the plane will still move forward, and will have air flow over the wings. The BS I was talking about a connection between plane and belt? WTF was I walking about? Eh I don't know why it took so long for me to realize it.

 

[bikinpunk 10+ year member]

Actually, Bernoulli's principle is not the reason a plane can fly. It might play a small role, but it is not the primary cause and is quite insignificant in comparison to the actual reason.
The reason a plane flies is essentially due to how it diverts the airflow. It diverts the airflow downward. Newton' Third Law; For every action there is an equal and opposite reaction. The action is the diversion of airflow downward. The reaction is lift. When air is directed downward, the object moves upward.

Though I'm no aeronautical engineer.....from what I understand Bernoulli is essentially no where in the calculations relating to wing design.

You're right, but due to Bernoulli's principal you have the reasons for lift.

I could try to dig up my old tests and notes and prove it to you, but you can just take my word and we can agree to somewhat disagree.

 

[ngsm13 5,000+ posts]

LAwl.

nG

 

[shortyg83 10+ year member]

OK. I actually thought long and hard about this last night, in bed.
After running many different senarios through my head, I am finally able to realize that the plane speed in the air can be matched to the speed of the belt and the plane will still move forward, and will have air flow over the wings. The BS I was talking about a connection between plane and belt? WTF was I walking about? Eh I don't know why it took so long for me to realize it.

Dont feel so bad I was blind at first too. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Fast1one 10+ year member]

Dont feel so bad I was blind at first too. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

So was I, but for no more than a minute, goodness...
Glad you figured it out, your still a tard though //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[DBfan187 5,000+ posts]

so it wasn't on last night? I dvr'd it anyway.