Airfoils play an important role in the function of most airplanes. Also known as aerofoils, they are cross-sectional shapes that promote lift. When inspecting an airplane’s wings, you may notice that they aren’t flat. Instead, they are curved. These curved, cross-sectional shapes are airfoils. To learn more about airfoils and how they work, keep reading.
#1) Increase Lift and Decrease Drag
Airfoils are designed to increase lift and decrease drag. As air flows over an airplane’s wings, they will create a pressure difference. The pressure will be higher on one side than on the other side. This pressure difference will increase the airplane’s lift and decrease its drag.
#2) Size and Shape Affect Lift
Both the size and shape of an airplane’s airfoils will affect its lift. All airfoils feature a cross-sectional shape. But the size of an airfoil, as well as its specific cross-sectional shape, will affect how much lift it produces. Some airfoils are able to produce more lift for the airplanes with which they are used than others.
#3) There’s a Suction and Pressure Surface
Airfoils have two surfaces: suction and pressure. Also known as the upper surface, the suction surface has lower static pressure and a higher velocity. The pressure surface, on the other hand, has a higher static pressure and a lower velocity. Suction and pressure surfaces are designed with different curvatures. The nuance in their respective curvature allows them to produce lift.
#4) Typically Require a Positive Angle of Attack
Most airfoils require a positive angle of attack. The angle of attack, of course, represents the angle at which the airfoil’s chord meets the air. As long as it’s positive, the airfoil will typically produce sufficient lift. With that said, some airfoils — particularly cambered airfoils — can generate enough lift to keep an airplane in the air with a neutral or zero angle of attack.
#5) Not Limited to Wings
When most people think of airfoils, they envision wings. Airfoils, however, aren’t limited to wings. Other components of an airplane can feature these same cross-sectional shapes. Propellers, for instance, often consist of an airfoil shape. If you inspect the blades on a propeller, you may notice that they aren’t flat. Like the wings on a typical airplane, they are curved.
In Conclusion
Airplanes are meticulously designed so that they can produce lift and, thus, stay in the air. Airfoils are one of the elements in an airplane’s design that’s responsible for their lift.
