Please let me remind all of you--this material is copyrighted. Though partially funded by NASA, it is still a private site. Therefore, before using our materials in any form, electronic or otherwise, you need to ask permission.
There are two ways to browse the site: (1) use the search button above to find specific materials using keywords; or,
(2) go to specific headings like history, principles or careers at specific levels above and click on the button. 
Teachers may go directly to the Teachers' Guide from the For Teachers button above or site browse as in (1) and  (2).

Airfoil Experiments - Level 1

EXPERIMENT 1

Equipment:

• Strip of notebook paper or newspaper, about 2 inches wide and 10 inches long
• Book
• Paper clips

The force that lifts an airplane and holds it up comes in part from the air that flows swiftly over and under its wings.

Make an airfoil (wing) by placing one end of the strip of paper between the pages of the book so that the other end hangs over the top as shown in diagram A. Move the book swiftly through the air, or blow across the top of the strip of paper. It flutters upward.

Hold the book in the breeze of an electric fan so the air blows over the top of the paper.

Take the strip of paper out of the book. Grasp one end of the paper and set it against your chin, just below your mouth. Hold it in place with your thumb and blow over the top of the strip. The paper rises. Try the same thing after you have fastened a paper clip on the end of the strip. See how many paperclips you can lift in this way.

It doesn't matter whether you move the air over the strip of paper by blowing or whether you move the paper rapidly through the air - either way it rises.

Press to see Animation for paper airfoil.


Bernoulli's principle states that an increase in the velocity of any fluid is always accompanied by a decrease in pressure. Air is a fluid. If you can cause the air to move rapidly on one side of a surface, the pressure on that side of the surface is less than that on its other side.

Bernoulli's principle works with an airplane wing. In motion, air hits the leading edge (front edge) of the wing. Some of the air moves under the wing, and some of it goes over the top. The air moving over the top of the curved wing must travel farther to reach the back of the wing; consequently it must travel faster than the air moving under the wing.  Therefore the air pressure on the top of the wing is less than that on the bottom of the wing.
Press to see Animation for Bernoulli's principle.

Many believe that use of Bernoulli's principle to explain lift is incorrect because flat wings (such as seen on balsa wood airplanes, paper planes and others) also create lift.  Please read How planes fly: the physical description of flight or Section 4.1 of Level 2 as well to get a fuller understanding of the creation of lift.

Send all comments to allstar@fiu.edu
© 1995-2008 ALLSTAR Network. All rights reserved worldwide.

Funded in part by

From Raytheon Aviation Educational Materials

Updated: March 12, 2004