Final answer:
The dihedral angle on the wings of birds and airplanes provides lateral stability during flight, ensuring the craft returns to a neutral position after disturbances. The upward angle creates a self-stabilizing effect due to the variation in lift produced. This is integral to the aerodynamics of flight and is supported by the functional adaptation of wings in nature and engineering.
Step-by-step explanation:
The wings of both birds and airplanes have a dihedral angle for stability during flight. The term 'dihedral' refers to the upward angle of the wings relative to the horizontal plane. This angle is critical for stabilizing the aircraft or bird laterally (roll stability), helping it to automatically return to its neutral flying position after a disturbance, such as a gust of wind. The effect can be imagined as a see-saw, where the wing with a higher altitude will experience more lift due to the dihedral angle, returning the aircraft to level flight.
Aerofoils, which are the shape of wings and propeller blades in both nature and engineering, contribute to this stability. Airplane wings make use of Bernoulli's principle and conservation of momentum to generate lift. The aerofoil's curved surface causes air to flow faster over the top, reducing pressure and thus resulting in an upward force. In birds, the intricate adaptation of feathers creates the necessary lift and thrust for flight. Primary feathers, especially, provide thrust, while the flexibility of the feathers reduces drag. In insects, the evolution of wings represents an entirely new trait, contributing to the effective control of flight.
Thus, the dihedral angle plays a significant role in the aerodynamics of flight, offering structural and functional advantages to flying animals and man-made aircraft alike. This angle is one of the key aspects ensuring that birds and airplanes can maintain stability during flight while responding effectively to the dynamics of the air around them.