The Ancient Chinese discovered that kites with curved surfaces flew better than kites with flat surfaces. A wing needs to have camber: the top needs to be slightly curved, like a bump, and the bottom is straight.
This is called an airfoil. Airfoils are designed to generate as much lift as possible with as little drag as possible. Here’s how you make an airfoil:
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Materials:
First, you set up how wide you want your wing to be. This is a chord line. One point on the chord line is the leading edge and one is the trailing edge.
Now add camber by pushing up the top surface until it curves. Now push that bump to the left so it’s more curved at the leading edge. How thick you make this will depend on how fast your wing is going to go and how much lift you need.
Now add the same thickness under the camber line to make the lower surface. Now you have an airfoil!
The airfoil uses Bernoulli’s principle. The top surface of the wing has more camber than the bottom surface, which means that air will flow faster over the top than it does underneath. This means that there’s less air pressure above the wing than under it, and this difference in air pressure makes lift.
How much lift? Well that depends on the airfoil shape, the size and shape of the wing, the angle it makes with the air, the density of the air, and how fast it’s going. Airplanes designed to fly slow have thicker airfoils than supersonic aircraft because the air flows slightly differently at fast versus slow speeds. Airplanes flying at high altitudes have less air molecules to generate lift in the same amount of air as lower flying planes.
If you’ve ever heard of “stalls”, it’s different when an airplane stalls than when a car stalls. What happens when a car stalls? The engine stops, right? If the engine stops in an airplane, it’s called an engine failure, not a stall. A stall is when the air stops flowing over the wing. The engine in an airplane can stop but air can still go over the wing, right? During an engine failure, a propeller airplane turns into a glider, which still can fly. So a stall happens when the wing tips up so high that air can’t flow over the top, so there’s no lower pressure and therefore no lift. If there’s no lift, the airplane turns basically into a rock and falls.
[/am4show]
This is called an airfoil. Airfoils are designed to generate as much lift as possible with as little drag as possible. Here’s how you make an airfoil:
[am4show have='p8;p9;p10;p37;p93;' guest_error='Guest error message' user_error='User error message' ]
Materials:
- index card
- tape
- skewer or pencil
First, you set up how wide you want your wing to be. This is a chord line. One point on the chord line is the leading edge and one is the trailing edge.
Now add camber by pushing up the top surface until it curves. Now push that bump to the left so it’s more curved at the leading edge. How thick you make this will depend on how fast your wing is going to go and how much lift you need.
Now add the same thickness under the camber line to make the lower surface. Now you have an airfoil!
The airfoil uses Bernoulli’s principle. The top surface of the wing has more camber than the bottom surface, which means that air will flow faster over the top than it does underneath. This means that there’s less air pressure above the wing than under it, and this difference in air pressure makes lift.
How much lift? Well that depends on the airfoil shape, the size and shape of the wing, the angle it makes with the air, the density of the air, and how fast it’s going. Airplanes designed to fly slow have thicker airfoils than supersonic aircraft because the air flows slightly differently at fast versus slow speeds. Airplanes flying at high altitudes have less air molecules to generate lift in the same amount of air as lower flying planes.
If you’ve ever heard of “stalls”, it’s different when an airplane stalls than when a car stalls. What happens when a car stalls? The engine stops, right? If the engine stops in an airplane, it’s called an engine failure, not a stall. A stall is when the air stops flowing over the wing. The engine in an airplane can stop but air can still go over the wing, right? During an engine failure, a propeller airplane turns into a glider, which still can fly. So a stall happens when the wing tips up so high that air can’t flow over the top, so there’s no lower pressure and therefore no lift. If there’s no lift, the airplane turns basically into a rock and falls.
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