Aerofoil

Aerofoil An aerofoil (or airfoil in American English) is a shape designed to generate lift when air flows over it. Aerofoils are fundamental components in the design of aircraft wings, helicopter rotor blades, propeller blades, and other devices that interact with air or other fluids.

Design and Function

The primary function of an aerofoil is to create a pressure difference between its upper and lower surfaces, resulting in lift. This is achieved through its shape, which typically features a curved upper surface and a flatter lower surface. The curvature of the upper surface causes the air to travel faster over it, reducing pressure according to Bernoulli's principle. The slower-moving air beneath the aerofoil maintains higher pressure, creating an upward force.

Key Parameters

Several parameters define the shape and performance of an aerofoil:

• Camber: The curvature of the aerofoil's mean line.
• Chord line: The straight line connecting the leading and trailing edges.
• Thickness: The distance between the upper and lower surfaces.
• Angle of attack: The angle between the chord line and the oncoming airflow.

Types of Aerofoils

Aerofoils can be classified into various types based on their design and application:

• Symmetrical aerofoils: These have identical upper and lower surfaces and are used in applications where lift is required in both directions, such as helicopter rotor blades.
• Cambered aerofoils: These have a curved upper surface and a flatter lower surface, providing higher lift and are commonly used in aircraft wings.

Applications

Aerofoils are used in a wide range of applications, including:

• Aircraft wings
• Helicopter rotor blades
• Wind turbine blades
• Propeller blades
• Automobile spoilers

Related Concepts

• Lift (force)
• Drag (physics)
• Bernoulli's principle
• Angle of attack
• Wing

See Also

• Wing
• Lift (force)
• Drag (physics)
• Bernoulli's principle
• Angle of attack
• Propeller
• Wind turbine