Plans, wings and lift

[skeeterm5]

As I understand it the wing of a plane is shaped so as to create airflow at different speeds across the two surfaces, thus creating a pressure differential that then provides lift.

How does a plane fly upside down for any length of time?

S

[15peter20]

In simple terms the pressure differential works when the wing is upside down as well but is much less efficient and requires a large angle of attack (i.e. angle to the oncoming airflow). There is also Newtonian lift which is a result of the deflection of the air downwards at the rear of the wing in relation to the oncoming airstream - this again works either way up. It is not easily described without pics so wikipedia is a good bet.

Finally, aircraft spending a lot of time upside down (i.e. aerobatic aircraft) will typically have symmetrical airfoils which provide the same lift either way up given a sufficient angle of attack.

Quick description, happy to expand if required!

[SlipStream77]

My guess would be angle of attack?

[skeeterm5]

thanks

[Ian Lancs]

No no no - it's all to do with lift pixies and fairies (or at least that's what I was "taught" during my aero lectures years ago...

[Mario149]

Back in the day when I was doing my Aero Eng degree I seem to remember a lecturer explaining the faster/slower airflow bit as the noddy/slightly fake explanation for lift (like how electrons orbiting atoms are treated up to GCSE chemistry). Actual reason was "circulation" or some such over the wing, but I forget because it's now been 7 years since uni where I actually had to properly use my brain!

Can anyone shed any light on either of those?

[bbc]

How they don't work:

http://www.telegraph.co.uk/science/science-news/90...

How they do work:

http://iopscience.iop.org/0031-9120/38/6/001/pdf/0...

[Hooli]

Skyhooks.

[XG332]

Magic

[Xenocide]

Could you make a plane take off from an upside down conveyor belt from stationary?

[deadtom]

Xenocide said:

Could you make a plane take off from an upside down conveyor belt from stationary?

I think it's best if you leave now.

[Hooli]

Xenocide said:

Could you make a plane take off from an upside down conveyor belt from stationary?

Surely if the conveyor belt is upside down the plane will just fall?

[warp9]

A whoosh parrot. Non?!

[Ray Luxury-Yacht]

Don't you basterds dare start a plane / conveyer belt divergence now, or ever again.

Or it will be bedtime with no tea, you hear me?

[Ayahuasca]

All my old books on aircraft have the traditional 'curved upper surface, flat lower surface, Bernoulli effect' explanation for lift which I believe is now known to be bks. The reality is apparently much simpler - the wing just pushes the air down and so the wing goes up.

[1point7bar]

Fast air flowing over flat surface, also seen in ground effect.
Angle of attack is lift/drag ratio of aerofoil.

[anonymous-user]

More importantly, and never before answered, what happens if you try to ride a conveyor belt in a plane ????

[1point7bar]

Sore bits.

[Chuck328]

Max_Torque said:

More importantly, and never before answered, what happens if you try to ride a conveyor belt in a plane ????

Something like this?

http://www.youtube.com/watch?v=GFomB-3weho

[Otispunkmeyer]

I had a good link for explaining this.

I'll try find it.

Basic explanation was angle of attack and redirection of air particles. The wing basically deflects air from the bottom and top of the wing downwards. Equal and opposite reaction, some upward force. There is also a pressure difference across the wing but it's. It enough to lift or suck the aircraft into the air.

Something about the coanda effect:

http://karmak.org/archive/2003/02/coanda_effect.ht...

Still looking for the other link. Had a good animation of where particles end up after a wing passes through a region of particles at speed

Edited by Otispunkmeyer on Sunday 26th February 12:45