Aeroplanes Flying

[Progenitor A]

I think that this might have been discussed before
Some conventional explanations tell us that it is the Venturi effect where air flows over a longer distance over the top curve of the cross section of a wing in comparison to the shorter distance it flows over the flatter surface curve of the bottom of the wing.

This differential in speeds causes a difference in pressure that causes an upward pressure on the wing, and it lifts


That may well be so, but when the same wing is placed upside down in the air stream (the areoplane is flying upside down) then the aircraft should be forced downward, shouldn't it?
But aeroplane happily fly upside down so there must be another force at play in addition to the Venturi effect - indeed this new force totally overwhelms any Venturi effect when the aerolane is flying upside down

This mechanism is, I believe, the pressure upward of the air being forced downward by the wing and has nothing to do with the Venturi effect

I raise the question again because Cambridge University has just produced a video that apparently repudiates the Venturi effect

www.telegraph.co.uk/science/science-video/9035320/How-aeroplanes-wings-really-work.html

[robinpike]

I didn't understand the point being made in the video?

It shows that the air above the wing does move faster than the air below the wing!

As to your question about planes flying upside down, the plane is flown upside down with the wing having an angle of attack, and it is this that keeps the plane up.

[Progenitor A]

Jan 27, 2012 19:04:13 GMT 1 robinpike said:

I didn't understand the point being made in the video?

It shows that the air above the wing does move faster than the air below the wing!

As to your question about planes flying upside down, the plane is flown upside down with the wing having an angle of attack, and it is this that keeps the plane up.

The 'angle of attack' keeps the plane up?

Don't think so!

[principled]

Nay.
i'd like to discuss this later this week when I have regular Internet. I've had a quick look at the video and it shows that the speed of the air above the aerofoil is faster than that below. so I can't quite see what the correction by the professor is all about.
P