How does Bernoulli's principle Explain how airplane wings work?

Answer 1

Bernoulli's principle says that air moving faster over the top of the wing is of lower pressure. The difference in the speed of the airflow between the top and bottom of the wing is due to the difference in "chord" length of the wing top and bottom. The classical wing shape has a longer chord over the top of the wing than the bottom. So the air must move faster over the top than the bottom. The difference in speed creates a difference in pressure. This pressure difference "sucks" the airplane up into the sky. Problem is...it isn't true, or at least it isn't the only factor causing lift. In particular, if this was the only thing causing lift then it would be impossible for a plane to fly upside down since the long chord of the wing would be on the bottom and the pressure difference would "suck" the plane downward. Most planes can indeed fly upside down. One possible reason why an airplane might not be able to fly upside down is whether or not the airframe was designed for the wing to be loaded upside down. A 707 has been flown upside down, so very large aircraft not specifically designed for aerobatics can indeed be flown upside down. Furthermore, not all aircraft wings even have unequal chords. Indeed, the Wright flyer's wing had equal chords. Most paper airplanes have wings with equal chords. The low pressure is insufficient to lift the airplane. Instead the airplane lifts primarily because the wings thrust a large amount of air downward as it passes the wing. Newton's third law. This thrust (lift) only occurs when the leading edge of the wing is above the trailing edge. If the plane is flown upside down then, as long as the leading edge is higher than the trailing edge, the air is still thrust downwards and the plane still lifts. This can be easily shown with a piece of stiff flat (equal top and bottom chords) cardboard held out the window of a moving car. If the front edge is above the trailing edge then the cardboard is forced upwards. If the front edge is below the trailing edge the cardboard is forced downwards. It is humorous that airplanes have been flying for over a century, but many students are still taught a completely bogus explanation, involving just the Bernoulli principle, for the phenomenon. The above answer does not 100% explain the behavior of a wing. Other factors, including Bernoulli's principle also contribute. The balance between the importance of say downward thrust of the air flow, the Bernoulli principle, drag, normal operation speed, normal operation altitude, wing strength, weight and a host of other factors control the optimal wing shape for a given aircraft. If you look at fighter aircraft which have a thinner wing design and that of a commercial 747 which have a much thicker wing design, which one would have the greater lift capacity? Which one is designed for speeds of 300-400 MPH versus supersonic flight (up to perhaps Mach 2)? Which one is designed for aerobatic maneuvers? What is the relationship between the thrust of the engines and the weight of the aircraft? Those factors, and many others, have a large affect on the optimal wing shape for a particular aircraft.

Answer 2

Bernoulli's principle was published by Daniel Bernoulli in his book 'Hydrodynamica' in 1738. It states that for an iviscid flow, the speed increase of fluid and the decrease in pressure occurs simultaneously.

Answer 3

The faster a fluid (a liquid or gas) moves, the lower its pressure is. So, by causing a fluid to move faster, you reduce its pressure. Airplanes have wings with a flat underside and a slightly curved topside. As the airplane moves forward, the air passing straight along the bottom of the wing does not move quite as quickly relative to the wing as the air above the wing, which has to pass along the longer, curved path above the wing. Fluids exert pressure not just downward, but upward, so the higher pressure air below the wing pushes up on the wing more than the air above the wing pushes down, due to the difference in the speed of the air above and below the wing. If the wing moves forward quickly enough, the difference is great enough that the air actually pushes up on the wing with enough force to lift the plane upward.

Answer 4

In the flow of a fluid, higher speed creates a lower pressure. When air (a fluid) moves over an airplane wing, the air moving over the TOP of the wing has to travel further than air moving over the bottom, so it is sped up. This creates lower pressure ABOVE the wing, and higher pressure air UNDER the wing pushes the wing up. Same principle applies to wind blowing across a sailboat sails.

Answer 5

The wind over the upper surface of the wing travels faster and that creates a low pressure column of air, which makes the plane lift.

Answer 6

If air pressure is applied to an object the pressure on the bottom must be greater than the pressure on the top. <3

Answer 7

The different paths above and below the wings of an aeroplane, where the air flows creates a suction which lifts the plane of the ground.

Answer 8

cause it goes up and down