Taking Flight

AviationAerodynamicsFlightAtoms & MoleculesFluids

Most of us have been building paper airplanes for as far back as we can remember, either in an attempt to cure boredom or while trying to catch someone's attention on the other side of the room. But when we fold up sheets of paper for flight, how can we build the ultimate in aircraft?

Explore what makes a good paper airplane to learn about the physics of flight and aerodynamics.

Materials Needed:

Paper of various weights and thicknesses, such as plain white paper, construction paper, cardstock Paper clips Stapler Scissors stopwatch

Doing the Activity:

If you’re working on this experiment by yourself, start by crafting a number of different paper airplanes. Try using different folding patterns to change the design, or try to build the same type of plane using different kinds of paper. You can also try adding extra weight with paper clips or staples, or cutting slats in the back of the wings. For inspiration on different paper airplane designs, check out http://www.paperairplanes.co.uk/planes.php If you are working in a large group, everyone can build their own paper airplane by using different folding patterns, types of paper, and extra weights. With your collection of planes in hand, let the flying begin! Start flying the planes and record both how long they stay in the air and how far they fly. Think about why some planes flew further or stayed up longer, with the help of the explanation below. Head back to the drawing board and try to design an even better plane, using what you've learned!

What’s Happening:

It may be easy enough to make a paper airplane that flies at least a little bit.

As you fold paper into wings, you're providing the structure for lift, which is the upward force on the plane from the air streaming below. When the lift is stronger than the force of gravity, the plane can stay up in the air.

To build a more efficient aircraft, however, there are some specific things to keep in mind.

Archimedes' Principle: An object surrounded by air is buoyed up by a force equal to the weight of the air displaced. In other words, the heavier the plane is, the broader the wing span needs to be to displace more air. When you change the weight of the plane (if you use a heavier paper or add paper clip weights), you'll need to compensate by changing the type of wings you build for your plane.

Bernoulli's Principle: The faster a fluid (such as air) moves, the less pressure that fluid exerts. The wording sounds complicated but the idea is simple: if you increase the speed of the air flowing over the wing compared to the air flowing under the wing, you will generate more lift to drive the plane upwards.

You can speed up the airflow above by adding surface area to the top of the wing (this is why the tops of wings on planes are slightly curved). This is what cutting slats in the back of your paper planes accomplished!

Air Resistance: Friction produces drag, which fights against the forward motion of the plane. In order to minimize this drag resistance, a plane should have a sleek and aerodynamic design so that the front of the plane encounters the minimum surface of air. Think of a pointed nose and slim smooth body!

Why it Matters:

While the lessons in this Lab experiment could help you take victory at your next paper airplane-making competition, they are based on ideas engineers use every day when designing full-sized aircrafts. In order to develop fuel-efficient planes out of different metal materials, engineers must consider the plane's weight, wing span and geometry.

Airplanes designed for different functions can have very different structures; think about how different commercial airplanes look compared to some fighter jets. What properties do you think the engineers considered the most valuable when designing these different planes?

References:

Adapted from an experiment posted by Lori Stewart on education.com

Alyson Kenward

I am a science writer from Calgary, Alberta and have recently begun to manage The Lab section of CurioCity. Having just completed my PhD in chemistry, I am now looking forward to sharing science with others through my writing. In my spare time, I keep busy training for and racing half-marathons and my secret pleasure is trying to work through each month's Food and Wine recipes with my partner Jeff.