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Wings and FlightHave you noticed the curved shape of a bird’s wing? An airplane’s wing is curved also. A wing is designed for flight. It has a special shape called an airfoil. An airfoil shape is used on wings, fans and propellers. The airfoil shape gives a lifting (aerodynamic) force when the air flows around it.
An airfoil has a thicker leading edge (front end) and a very thin trailing edge (back end). In between the leading edge and the trailing edge, an airfoil is curved on both the top and the bottom surfaces. Usually though the top surface has more of a curve than the bottom surface. When a surface is curved like that, we say that it has camber.
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An
airfoil uses Bernoulli’s Principle. Since the top surface of the wing
has more camber (curve) than the bottom surface, the air flows faster
over the top of the wing than it does underneath. The faster airflow over
the top of the airfoil has lower pressure than the airflow underneath.
With greater air pressure underneath and lower air pressure on top, the
airfoil will lift. Bernoulli’s Principle was discovered by the scientist
Daniel Bernoulli. He discovered that fast flowing fluids (in this case,
water), had lower pressure than slower flowing fluids. This also held
true for airflow.
