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Demos: 2C-08 Air Foil

This demonstration illustrates the lift on an airfoil, although it is somewhat misleading when related to real airplane wings. In this demo, the air flows over the wing but is prevented from flowing under the wing by a barrier. Thus there is a lower pressure above the wing and, because the wing is very light (Styrofoam), it is lifted.

Directions: Direct the stream from the air hose over the top of the wing. Adjust the angle of the air flow for optimum effect.

Suggestions for Presentation: Caution the students that this is a very misleading demonstration, as it relates to real airplane wings. In this case, there is decidedly a difference in air pressure and the wing is lifted. In real airplanes, there may be some lift effect due to the Bernoulli effect, but the primary lift comes from the direct impact of the air on the underside of the wing, which is angled slightly upward. Ask the students this: Suppose the Bernoulli effect were the main factor in lift and the wing is cambered to effect this result. What would happen if the plane tries to fly upside down? Planes do fly upside down quite successfully.

Applications: It probably isn’t a good idea to relate this to airplanes for the above reasons, but perhaps a closer analogy is the wind blowing between the main and jib on a sailboat.

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Last Updated: Nov 30, 2023 11:25 AM

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