Thursday Teaching {Flight}

 Project: Airplane Wings & Ailerons

Concept: Flight

 I actually want to get to two concepts today. The first involves pressure and how an airplane wing helps an airplane to fly. This can get a little complicated, so I'll just leave a simple explanation and experiment. If your kids aren't quite ready for that yet, skip on ahead to the Airplane Ailerons experiment. Enjoy!

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We know how an airplane is able to fly thanks to our good friend Daniel Bernoulli, who discovered a fact known fittingly as the Bernoulli principle.

Wikipedia says: The Bernoulli principle can be used to calculate the lift force on an airfoil if the behaviour of the fluid flow in the vicinity of the foil is known. For example, if the air flowing past the top surface of an aircraft wing is moving faster than the air flowing past the bottom surface, then Bernoulli's principle implies that the pressure on the surfaces of the wing will be lower above than below. 

I say: The pressure of a moving gas decreases as its speed increases.

Because the shape of an airplane wing causes the air to move faster above than below, there is lower pressure above the wing. Higher pressure underneath the wing pushes the wing up and produces lift.

 

You can test the Bernoulli principle using a business card and a match. Adults, always be the one in charge of the matches. This experiment really is a 2-person deal, so I'll have to wait until the husband comes home to show you pictures. But, you don't have to wait - try it now!

 

Hold a business card in front of your mouth with a lit candle on the other side of the business card. 

Blow hard onto the business card. What happens to the flame of the match? 

... It moves toward you, toward the business card!

This is because you are creating a moving gas between your mouth and the card. Because air is moving quickly, you are creating a lower pressure. 

There is no moving gas between the card and the match. Air is moving slowly, creating a higher pressure.

 The higher pressure pushes the flame toward the area of lower pressure.

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This second experiment comes from the book Potentially Catastrophic Science by Sean Connelly.

There are a few different 'flaps' on an airplane wing that control how the airplane is going to move. An aileron is one such 'flap'. Ailerons on a wing control the rolling of the airplane. 

Picture yourself in an airplane. The airplane turns left. Easy, right? Well, the airplane doesn't turn exactly like a car turns. First, you tilt a little to the left (or roll a little to the left) before you turn. Can you imagine that feeling of rolling a bit before turning? Ailerons control that rolling.

In this experiment, you will create 4 identical airplanes. However, each airplane will have a different aileron configuration. Below are paper airplane instructions if you need them.

Fold your 'flaps' (ailerons) to match the above planes and let them fly!

You should have the following results: 

* One will fly nose-up towards the ceiling before falling

* One will nose-dive into the ground

* One will perfectly spiral to the left

* One will perfectly spiral to the right

What did you learn?

For really cool paper airplane designs, check out these websites. Your kids will love them!

http://www.funpaperairplanes.com/

http://www.amazingpaperairplanes.com/Simple.html

 http://www.paperairplanes.co.uk/planes.php