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Author Topic: Physics of flight?  (Read 19969 times)

Offline Viggen

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Physics of flight?
« on: October 16, 2006, 06:08:50 PM »
There is a question that is troubling my little mind... We all know how a wing works and that it produces lift. But if the aircraft is flying upside down, then the wing must produce downforce instead of lift. Now how is it possible for aircraft to fly upside down?? Is it the forward motion from the engine/engines, or what is the effect/physic that makes this possible??

Can someone explain this in laymans terms, so i can understand it.  :)
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Patrik S.

Offline Gripen

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Re: Physics of flight?
« Reply #1 on: October 17, 2006, 08:20:44 AM »
i thought that the air going over the wings and the speed from the engine kept the plane flying normally, so upside down would be the same?

the engines are still propelling it, which makes the wind go over the wings, so wouldnt it be the same, just a little more touchy if you aimed the nose down,  the plane would basically fall!

i dont know
im not aeronautical engineer

Offline Webmaster

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Re: Physics of flight?
« Reply #2 on: October 17, 2006, 07:02:27 PM »
Ok, let me start with saying that I am not an aerospace engineer either, nor a pilot. Not sure if there is an easy answer. But don't forget the control inputs and pitch level, it's not just a matter of wing profile. Even when you are flying right side up, you have to balance your pitch to your speed by using the trim. Your lift is reduced by having the inverted wing, but it's not completely converted into a downforce, the wing still creates lift only with lesser effect, which may not be enough to keep you flying unless you adjust your pitch and speed. Because you adjust the pitch of your aircraft, you can still generate enough lift to keep flying, depending on your speed and aircraft characteristics of course. In fighter jets, the wings are flatter, speed contributes more to lift than the wing profile, and the computer will make adjustments for you.

I think we need an aerospace engineer on this forum to provide some better drawings and explanations  :(

« Last Edit: October 22, 2006, 09:25:54 PM by Webmaster »
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Offline Viggen

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Re: Physics of flight?
« Reply #3 on: October 17, 2006, 07:54:52 PM »
Ok. So what i have understood, its basicly down to the forward motion/speed of the aircraft that makes it possible.  Why this idea entered my mind was mostly because of racingcars. Their wings produce alot of downforce, enough to drive upside down through a tunnel when they reach speeds over 290 Km/h. It just hit me that you should get lift here instead of downforce if you are driving upside down.  ???

There is big diffrences between wings on a formula one car versus airplanes, but the ground concept they build wings on is the same. If if im not completly wrong and way out there. ;)
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Re: Physics of flight?
« Reply #4 on: October 18, 2006, 02:40:12 PM »
It just hit me that you should get lift here instead of downforce if you are driving upside down.  ???

Yeah, but they are upside down, so that lift is downforce onto the ceiling...
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Offline Viggen

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Re: Physics of flight?
« Reply #5 on: October 19, 2006, 12:10:35 AM »
Not if its upside down, because of the shape of the wing....Ahhhh!! This drives me nuts....  :o Guess im just to stupid to understand this. hehe, no wonder im unemployed at the moment.  ;D
« Last Edit: October 19, 2006, 12:16:47 AM by Viggen »
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Patrik S.

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Re: Physics of flight?
« Reply #6 on: October 19, 2006, 01:25:28 AM »
They got wings to push the car down, so when it is inverted, it pushed them up... the force then sticks the cars to the ceiling of the tunnel instead of the road....

Unemployed? So you should have time to fnish the Viggen section,  >:D Hehe, sorry, that's too bad man. Maybe work abroad is an option, like Finland or Norway?
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Offline Gripen

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Re: Physics of flight?
« Reply #7 on: October 19, 2006, 12:02:19 PM »
hey you could make you own Military Aviation Forum thing, and be the WM of that

a little competition never hurt no one!

Offline Viggen

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Re: Physics of flight?
« Reply #8 on: October 19, 2006, 01:54:23 PM »
Maybe i just need to to get back to school...
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Offline Viggen

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Re: Physics of flight?
« Reply #9 on: October 19, 2006, 10:11:09 PM »
I asked a friend of mine who fly planes about this today. Guess what???  Our dear webmaster was right again, i got the same answer from my friend.  The wing will still produce lift if you are upside down, you will just need to adjust the power, give it more throttle and rudder input (dive).  It is not just the shape of the wing that makes it possible, it is all combined.  :)

No more sleepless nights for me... Thanks to you two rascals!  :D

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Patrik S.

Offline Gripen

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Re: Physics of flight?
« Reply #10 on: October 20, 2006, 07:54:40 AM »
Question: Whose the rascals

And random thing: dont let the wings fall off otherwise you are sooooo f****d!!!

Offline Webmaster

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Re: Physics of flight?
« Reply #11 on: October 20, 2006, 06:59:15 PM »
I asked a friend of mine who fly planes about this today. Guess what???  Our dear webmaster was right again, i got the same answer from my friend.  The wing will still produce lift if you are upside down, you will just need to adjust the power, give it more throttle and rudder input (dive).  It is not just the shape of the wing that makes it possible, it is all combined.  :)

No more sleepless nights for me... Thanks to you two rascals!  :D

Right, and I now see some problem in both answers, of course it's not the rudder (yaw moving), but the stick (pitch) and this controls not the ailerons I have drawn on the wings, but the elevators on the horizontal tail planes or the entire tail planes and/or canards on some aircraft. You might have to use the rudder in propellor driven aircraft though, to compensate for the drift because of the power up.
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